MIPS provides a much cleaner upgrade path going forward than ARM. MIPS64 is a very clean extension to MIPS32. All of the MIPS32 instructions behave the same except that they are sign extended to 64-bit. 64-bit ARM on the other hand has almost nothing in common with ARM32. The instruction encoding is totally different. The register definitions are also completely different. A lot of the things that made ARM ARM are gone such as conditional execution.
I have spent many years working with MIPS and the last three working for a 64-bit multi-core MIPS manufacturer. MIPS also allows for clean extensions to the instruction set by various vendors, something ARM does not allow. For example, my employer has added a lot of instructions using coprocessor 2 (COP2) to add encryption, hashing, CRCs and more without breaking standard MIPS compatibility since COP2 is typically reserved for vendor extensions.
MIPS page tables are also interesting. They are entirely managed by software, allowing the operating system to use whatever format they want for them. While some vendors have added hardware walkers they typically don't make much difference in performance.
MIPS32 is fairly old and many implementations don't provide cache coherency which is a pain in the butt and impacts performance but the ones I deal with (Cavium's OCTEON processors) are fully cache coherent.
As for doing encryption in the instruction set it allows full acceleration in user space without needing to deal with descriptors or DMA or userkernel transitions.
Perhaps the only thing I would get rid of is the branch delay slot. It no longer really buys anything. The MIPS tools are much more mature than ARM, especially for 64-bit support. There are 32 general purpose registers with register 0 always being 0.
With ARM64 most of the interesting ARM features are gone and in fact it looks a lot more like MIPS except that the instruction decoding is a lot more complicated. MIPS hasn't been standing still either. Extensions have been added for things like virtualization, 16-bit instructions (like Thumb) which usually don't buy you much and some multimedia extensions.
I periodically work on MIPS assembly language with some of the bootloader stuff I do. All I can say is it's a joy to work with compared to X86 and is quite elegant. It's nice when I can have just a couple dozen lines of assembly language put a stack in cache memory and go straight to 64-bit C code. At this point it's quite hard for me to beat recent versions of GCC when it comes to optimizing code.
I don't know why they're limiting their Warrior P-Class CPU core to 32-bits though. Moving to 64-bit MIPS is not very difficult. Personally I'd love to see 32-bit MIPS go away and just do 64-bit MIPS and use either the N32 or N64 ABI. N32 runs in 64-bit mode but with 32-bit addressing so you get all the advantages of 32-bit pointers and 64-bit registers.
My employer makes MIPS processors with up to 32 cores and soon will have 48 cores and fully support Linux.
While I don't believe 600,000 miles I do believe there should be no problems getting at least 200,000 miles. Even then, the degradation is gradual so it's not like it suddenly fails and you have a sudden unexpected huge expense.
Tesla offers a plan where for $12,000 you will get a new battery pack after 8 years. For every additional year you wait they knock off $1000. In my case I took a good chunk of that and bought a bunch of Tesla stock at $35. It's hovering around $185/share right now.
The A/C should need a lot less maintenance since unlike mode ICE cars the compressor is electric and is completely sealed. Since no hoses are needed to go to an ICE that vibrates and moves, leaks should be less likely. There's no clutch to wear out either. As far as electrical systems, I have never had a problem with any of my cars, my last being a 2007 Prius, which has a lot of electrical systems. In some ways Tesla is simpler. It lacks many of the sensors an ICE car has, i.e. knock sensors, mass air flow sensors, throttle controls, oxygen sensors, oil pressure, fuel gauge, etc.
What sensors it does have tend to be temperature sensors, voltage and current sensors. The model S does have a number of valves and pumps for coolant since the cooling system is more complex, cooling the motor, inverter, charging units and battery as well as tying into the A/C system. It changes the flow depending on conditions and whether it's warming or cooling the battery and the climate control system. This is one of the main reasons the Model S does not suffer the problems the Leaf does. There have not been reports of any significant loss of range in hot climates and the cooling system was tested in Death Valley.
To help the battery last longer typically it is not charged to 100%. While it is possible it is not recommended to do it all the time. The only time I do a range charge is if I know I'm going on a long trip, otherwise I let it charge to 80%. Also unlike the Leaf, there are no issues doing rapid charges at the Superchargers. The Leaf's battery suffers when using the high output Chademo chargers.
The Leaf is an example of how not to do batteries. The Leaf does not have proper cooling of the battery pack. Tesla has much better battery management with active cooling as well as they use a different chemistry. The energy density of Tesla's batteries is also much higher than the Leaf.
One of the people I spoke with at the Tesla factory said that the motor is lubricated for 12 years. Presumably after 12 years they need to add more grease. In the Model S I believe it is fairly easy to remove the electric motor and drivetrain from the chassis. In a video it shows them installing it as a single module to the chassis in under 5 minutes. Granted it will take more time than when they install it in the factory, but it should be a lot easier than an ICE car.
I took much of the money I would spend on the $12K replacement and bought a bunch of their stock at $35. It's the best investment I ever made. I don't think I'll need to replace the battery after 8 years.
Elon Musk stated that his goal is for Tesla to not make a profit out of service. My experience when I broke something on my car (so it wasn't handled by warranty) was that their repair cost was a fraction of what the local Toyota dealership would have charged me to make a similar repair.
There really is a lot less to go wrong.
No oil and filter changes. No spark plugs. The coolant should last a lot longer. No belts to replace. No fuel pumps to die, exhaust leaks or oil leaks to deal with. No gaskets to be replaced or leak. No smog and related components like catalytic converters to deal with. No transmission fluid to change or clutches to wear out. The brake pads should last a lot longer since most braking is regenerative. The car is very well engineered. They did not cut corners to reduce costs in terms of suspension and drive train. According to a friend of mine who works there (an engineer on the drive train) they significantly over engineered things since they had to get it right the first time.
While I have had some things fixed under service, those things typically fall under creaks and rattles which are understandable given that my car has a VIN a little over 5000. They've addressed most if not all of the issues in later VIN numbers.
A gasoline engine has far more mechanical parts and things to go wrong, a lot more pumps and hoses, parts rubbing against each other, etc.
As for the battery, from my research the cells should be good for at least 3000 full charge discharge cycles. If I'm extremely conservative in estimating 200 miles of range per charge (I get significantly more) that works out to 600,000 miles.
There are some things that may wear out faster, such as the pop-out door handles (the early versions had problems). The electric motor, as opposed to an internal combustion engine, has no friction points other than the bearings, and it has a lot less than a gasoline engine.
One of the issues I had was the 12V battery dying. They got a bad batch of lead acid batteries and I ended up with one of them. They called me up when they detected the problem in the logs to schedule its replacement.
As for software issues, they regularly update it to fix bugs and add new features. They do this over the air and allow me to choose if and when to install an update.
I can stream video perfectly using MHL through the micro USB connector on my phone using a $8 adapter while it is still able to charge at the same time. I can also just stream the video wirelessly directly to my TV by using standard protocols which Apple does not support.
Actually it is being rather optimistic in its estimate. It's assuming driving 55MPh with the cruise control on (where it reports 60). I get 50 with the EPA estimate, which is also a little optimistic so realistically I get a bit under 50 miles of charge with everyday driving which is about 60% highway, 40% city streets. 19kw will not propel the car for normal driving. The 50 miles is taking into account regenerative braking as well. Yes, you pick up energy going downhill, but it doesn't match the extra energy required going uphill. Then there's also the safety issue of hauling a trailer. Here in California the law is vehicles hauling a trailer are limited to 55MPH. Then you also have a thick cable that would have to plug in to the side of the vehicle and go to the trailer. Then there's also the safety issues of hauling a trailer around, especially when you have a car that goes 0-60 in 4.2 seconds and can brake from 60-0 in 108 feet. I don't know about you, but I certainly don't want to have to worry about a trailer behind me nor would I want to be limited to 55 when on many interstates the speed limit is 70. Charging at the super chargers is not an issue. Yes, it adds some extra time, but not a huge amount, especially when you consider it's free. Spend the money you would on gas getting a nice meal, or do a battery swap if you're in a hurry. It takes around 90 seconds.
I have an 80A 240V charger at home and the car reports the charging rate based on that. It is more like 50 miles of range per hour of charging. Plus if I haul a trailer around that will significantly reduce the range due to the added drag and friction involved, reducing the range further.
I agree, the Prius is rather ugly, though not nearly as bad as say the Leaf. I say this as a Prius owner who now drives a Tesla. (My Prius is very rarely driven now, not since June).
0 - 32F should not have a huge impact on range, maybe 20-25% with the Tesla. After all, they are pushing heavily into Norway. For heating it uses a combination of heat pump or resistive elements depending on what is needed so it's not nearly as bad as the Leaf, which only uses resistive elements from what I understand.
I have had no problem with road trips with my Tesla model S. The Supercharger network makes them quite doable. My last trip was from the Bay Area up to Lake Tahoe (destination at 7200'). Admittedly while it's a bit under 250 miles, I went from near sea level to 7200' and it was over 100F for much of the drive. I stopped in Folsom to get lunch while charging (for free). By the time we finished our burgers the car was ready to go.
Right now the biggest limitation is waiting for Tesla to further build out their Supercharger network. Apparently they have all the equipment and everything lined up but most of the delays are due to city permits. In at least one location in Texas they were prevented from installing one due to the local representative being in the pocket of the car dealerships. They are expanding their network so in the near future this won't be an issue for me.
Also, in the near future they will be offering battery swapping when driving down to Los Angeles where the delay is just over 90 seconds to swap out the battery with a fully charged one. On the return trip I will end up with my original battery back.
The Nissan Leaf is a different story. I have a good friend with a Leaf. Even for trips around the Bay Area he is always having to stop in various places to charge due to the car's limited range. To make matters worse, since Nissan doesn't have adequate cooling of their battery using the ChaDeMo chargers is hard on the batteries and the batteries lose capacity quickly in hot climates. Right now I would recommend not buying a Leaf. Lease one and wait until they improve their battery technology in the next year or so.
The J1772 connector is not really capable of running an electric car even at 240v/80A (19.2KW) at freeway speeds. If things ran at 100% efficiency it could produce 25.6HP.
There are advantages and disadvantages of 64-bit mode. In the case of ARM, having double the number of registers should add a noticeable improvement. The main disadvantage of using a 64-bit ABI is that now pointers consume twice as much memory and in the case of RISC processors, loading 64-bit constants into registers can take more instructions. There is ongoing work with ARM to provide a 32-bit ABI using the 64-bit mode, much like how MIPS has the N32 and N64 ABIs (most of my experience is with 64-bit MIPS but much of it applies to ARM). In the case of ARM, having twice the number of registers should make a noticeable improvement since unlike X86 most instructions don't operate on memory locations directly except via load/store.
One weakness of 64-bit ARM is the instruction set is very new and the tools are still maturing. It was not necessarily the best thought out instruction set either and the instruction binary encoding is overly complex, making a lot more work for the toolchain developers. The difference between ARM 32 and ARM 64 is far greater than the difference between X86 and X86_64.
I learned long ago after some close calls to back everything up. In my case for my desktop I store my data on a XFS partition stored on a RAID 5 hard drive array. I also am using Crashplan to back up all of my data, both to a removeable hard drive and to the cloud with over 3TB of data backed up. The nice thing about Crashplan is that it continually backs up, taking periodic snapshots so I can restore a previous version of a file if I wish. The main drawbacks of Crashplan are that it runs on Java and can be a memory pig. I pay $6/month for unlimited backup of up to 10 machines and have several computers backed up with them now. With the proper settings on my router I don't even notice all the backup traffic running in the background.
Since I have had sudden SSD failures in the past I also dump my root XFS filesystem weekly onto my RAID array (it takes under a minute to run xfsdump) and incremental backups nightly and those dumps get backed up on the cloud as well.
I have found the XFS tools to be quite good at recovery when things go really bad. When running software RAID 1 I had problems where drives would drop out of the array for apparently no reason and I have had several occasions where while rebuilding the other drive would pop out of the array. Switching to an Areca hardware raid controller with battery backed DRAM ended those problems (besides seeing a big performance improvement).
I have found the RAID controller to work well when drive failure occurs and it even recovered after human error (I accidentally disconnected one of the active drives while it was rebuilding and reconnected it).
I won't use btrfs yet. The last time I tried it about 6 months ago it was quite slow and I have a lot of concerns about the storage filling up due to COW that have not been adqeuately addressed as far as I could tell. I tried setting it up for a Cyrus IMAP server on an Intel SSD and it was unusably slow just untaring all the files so I ended up going back to XFS.
SSDs are still relatively new. I have had issues with some firmware versions and had one fail catastrophically after only 2 weeks of use. I have also had compact flash and SD devices suddenly fail. My experience is that usually mechanical hard drives give some warning (i.e. SMART) and they tend to last years. I have a server I just retired where the hard drive had 10 years on the clock according to SMART.
As the owner of a Model S I looked in to the battery longevity. The battery pack should be good for a minimum of 8 years and likely considerably longer. From what information I have been able to gather, the cells are good for 3000 full charge/discharge cycles. Being very conservative and giving 200 miles of range per full charge (which is usually a fair amount more) that works out to 600,000 miles.
Plus it has been shown that replacing a battery pack is trivial with an automated system that can replace a battery in about 90 seconds.
The maintenance should be considerably less. The motor won't need an "oil change" for 12 years according to a tech I spoke with at the factory. Tesla has also stated that their goal is to not make a profit on service and maintenance, which is a far cry from the dealerships.
Right now the only way to buy a Tesla is online through their web site. It was a far more pleasant experience than dealing with dealerships trying to get a car in the color with the options I wanted then having to haggle over the price.
The maintenance schedule suggests taking the car in once a year for service. The warranty covers everything, including wiper blades and brake pads. Brakes shouldn't need service since they're hardly used. About the only thing they have to do other than inspections are to rotate the tires, change the cabin air filter and the wiper blades. The only other part that might need servicing periodically is the lead-acid 12v battery.
There are far fewer things to go wrong mechanically with the car considering that there's no transmission (just two gears with a 9.71:1 gear reduction) and an induction motor. As it is, the entire drive assembly can be easily removed and replaced (it takes them under 5 minutes to bolt the whole assembly in place at the factory). There's coolant, but it probably needs changing far less frequently. The AC should be a lot less prone to leaking since there's no engine mounted compressor with flexible hoses. There's no spark plugs, oil pumps, fuel pumps, fuel filters, air filters (other than cabin), EGR valves, oxygen sensors, catalytic converters, etc to wear out. Similarly, there's no oil changes, problems with warped heads, valves, camshafts, piston rings or all the other parts that wear. The only thing that can basically wear is the differential and bearings and the standard suspension stuff.
Dealerships are just a way to insert middlemen where they're not needed, and they're a monopoly by design. Usually you can't put in a competing dealership within a certain distance of an existing dealership unless they sell a different brand of car. That gives dealerships a local monopoly.
I disagree. It will cause fewer problems when having to resample. For example, usually DVDs and blu-rays require a 48KHz sampling rate. The additional bits and bitrate are also useful when mixing or processing the audio later for those who choose to do so.
According to a talk I attended given by Elon they use their own chemistry (LiCoAl). They are also automotive grade and are not the same as the consumer cells. Apparently Tesla can also use other manufacturers if needed as well.
Yes. Each cell in the model S is around 3.1Ah which is pretty high as far as energy density goes. Panasonic has some new cells that are even higher (3.7Ah) though it may be some time until they are qualified or deemed reliable enough to use in a car.
No, the reason they use 7000 cells is for reliability and cost. Other car companies use much larger cells, however the cost for those larger cells is high and the energy density is a lot lower than what Tesla is doing.
The batteries have to be reliable and not catch fire or explode. In the case of the large cells most car manufacturers use, they use a very safe chemistry. The drawback is that the energy density is a lot lower and the cost is high. Tesla went a different route. They chose the 18650 cell for cost and safety reasons. The Tesla battery pack is designed so that if a cell explodes it doesn't cascade into other cells or cause the battery pack to fail. Tesla has a much higher energy density than other automotive battery packs out there and it has been estimated that they also have the lowest cost as well for that density, estimated to be a fraction of what Nissan is paying for their Leaf on a per-kwh basis.
Tesla's 18650 cells are different than the cells you see on Amazon. For one thing, they do not have the protection circuits built in. The protection circuit is for each group of cells in the pack. Second, they lack the bump on the positive terminal since a wire is welded to the positive terminal. Tesla has done a lot with the cell design to minimize the cost. While it is the same form factor as a laptop battery it is not the same. The chemistry is also a bit different in order to be suitable for an electric car.
It has been estimated that Tesla pays under $2 per cell but nobody except Tesla and Panasonic know the actual cost. Tesla also gets the economy of scale. They go through 3-4 million cells per week acording to one of the techs I spoke with at the factory.
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MIPS provides a much cleaner upgrade path going forward than ARM. MIPS64 is a very clean extension to MIPS32. All of the MIPS32 instructions behave the same except that they are sign extended to 64-bit. 64-bit ARM on the other hand has almost nothing in common with ARM32. The instruction encoding is totally different. The register definitions are also completely different. A lot of the things that made ARM ARM are gone such as conditional execution.
I have spent many years working with MIPS and the last three working for a 64-bit multi-core MIPS manufacturer. MIPS also allows for clean extensions to the instruction set by various vendors, something ARM does not allow. For example, my employer has added a lot of instructions using coprocessor 2 (COP2) to add encryption, hashing, CRCs and more without breaking standard MIPS compatibility since COP2 is typically reserved for vendor extensions.
MIPS page tables are also interesting. They are entirely managed by software, allowing the operating system to use whatever format they want for them. While some vendors have added hardware walkers they typically don't make much difference in performance.
MIPS32 is fairly old and many implementations don't provide cache coherency which is a pain in the butt and impacts performance but the ones I deal with (Cavium's OCTEON processors) are fully cache coherent.
As for doing encryption in the instruction set it allows full acceleration in user space without needing to deal with descriptors or DMA or userkernel transitions.
Perhaps the only thing I would get rid of is the branch delay slot. It no longer really buys anything. The MIPS tools are much more mature than ARM, especially for 64-bit support. There are 32 general purpose registers with register 0 always being 0.
With ARM64 most of the interesting ARM features are gone and in fact it looks a lot more like MIPS except that the instruction decoding is a lot more complicated. MIPS hasn't been standing still either. Extensions have been added for things like virtualization, 16-bit instructions (like Thumb) which usually don't buy you much and some multimedia extensions.
I periodically work on MIPS assembly language with some of the bootloader stuff I do. All I can say is it's a joy to work with compared to X86 and is quite elegant. It's nice when I can have just a couple dozen lines of assembly language put a stack in cache memory and go straight to 64-bit C code. At this point it's quite hard for me to beat recent versions of GCC when it comes to optimizing code.
I don't know why they're limiting their Warrior P-Class CPU core to 32-bits though. Moving to 64-bit MIPS is not very difficult. Personally I'd love to see 32-bit MIPS go away and just do 64-bit MIPS and use either the N32 or N64 ABI. N32 runs in 64-bit mode but with 32-bit addressing so you get all the advantages of 32-bit pointers and 64-bit registers.
My employer makes MIPS processors with up to 32 cores and soon will have 48 cores and fully support Linux.
While I don't believe 600,000 miles I do believe there should be no problems getting at least 200,000 miles. Even then, the degradation is gradual so it's not like it suddenly fails and you have a sudden unexpected huge expense.
Tolerance limits, making it overly strong.
Tesla offers a plan where for $12,000 you will get a new battery pack after 8 years. For every additional year you wait they knock off $1000. In my case I took a good chunk of that and bought a bunch of Tesla stock at $35. It's hovering around $185/share right now.
The A/C should need a lot less maintenance since unlike mode ICE cars the compressor is electric and is completely sealed. Since no hoses are needed to go to an ICE that vibrates and moves, leaks should be less likely. There's no clutch to wear out either. As far as electrical systems, I have never had a problem with any of my cars, my last being a 2007 Prius, which has a lot of electrical systems. In some ways Tesla is simpler. It lacks many of the sensors an ICE car has, i.e. knock sensors, mass air flow sensors, throttle controls, oxygen sensors, oil pressure, fuel gauge, etc.
What sensors it does have tend to be temperature sensors, voltage and current sensors. The model S does have a number of valves and pumps for coolant since the cooling system is more complex, cooling the motor, inverter, charging units and battery as well as tying into the A/C system. It changes the flow depending on conditions and whether it's warming or cooling the battery and the climate control system. This is one of the main reasons the Model S does not suffer the problems the Leaf does. There have not been reports of any significant loss of range in hot climates and the cooling system was tested in Death Valley.
To help the battery last longer typically it is not charged to 100%. While it is possible it is not recommended to do it all the time. The only time I do a range charge is if I know I'm going on a long trip, otherwise I let it charge to 80%. Also unlike the Leaf, there are no issues doing rapid charges at the Superchargers. The Leaf's battery suffers when using the high output Chademo chargers.
The Leaf is an example of how not to do batteries. The Leaf does not have proper cooling of the battery pack. Tesla has much better battery management with active cooling as well as they use a different chemistry. The energy density of Tesla's batteries is also much higher than the Leaf.
One of the people I spoke with at the Tesla factory said that the motor is lubricated for 12 years. Presumably after 12 years they need to add more grease. In the Model S I believe it is fairly easy to remove the electric motor and drivetrain from the chassis. In a video it shows them installing it as a single module to the chassis in under 5 minutes. Granted it will take more time than when they install it in the factory, but it should be a lot easier than an ICE car.
http://www.youtube.com/watch?v=VUgDcA1pZAM starting at around 40 minutes in.
I took much of the money I would spend on the $12K replacement and bought a bunch of their stock at $35. It's the best investment I ever made. I don't think I'll need to replace the battery after 8 years.
Elon Musk stated that his goal is for Tesla to not make a profit out of service. My experience when I broke something on my car (so it wasn't handled by warranty) was that their repair cost was a fraction of what the local Toyota dealership would have charged me to make a similar repair.
There really is a lot less to go wrong.
No oil and filter changes. No spark plugs. The coolant should last a lot longer. No belts to replace. No fuel pumps to die, exhaust leaks or oil leaks to deal with. No gaskets to be replaced or leak. No smog and related components like catalytic converters to deal with. No transmission fluid to change or clutches to wear out. The brake pads should last a lot longer since most braking is regenerative. The car is very well engineered. They did not cut corners to reduce costs in terms of suspension and drive train. According to a friend of mine who works there (an engineer on the drive train) they significantly over engineered things since they had to get it right the first time.
While I have had some things fixed under service, those things typically fall under creaks and rattles which are understandable given that my car has a VIN a little over 5000. They've addressed most if not all of the issues in later VIN numbers.
A gasoline engine has far more mechanical parts and things to go wrong, a lot more pumps and hoses, parts rubbing against each other, etc.
As for the battery, from my research the cells should be good for at least 3000 full charge discharge cycles. If I'm extremely conservative in estimating 200 miles of range per charge (I get significantly more) that works out to 600,000 miles.
There are some things that may wear out faster, such as the pop-out door handles (the early versions had problems). The electric motor, as opposed to an internal combustion engine, has no friction points other than the bearings, and it has a lot less than a gasoline engine.
One of the issues I had was the 12V battery dying. They got a bad batch of lead acid batteries and I ended up with one of them. They called me up when they detected the problem in the logs to schedule its replacement.
As for software issues, they regularly update it to fix bugs and add new features. They do this over the air and allow me to choose if and when to install an update.
I can stream video perfectly using MHL through the micro USB connector on my phone using a $8 adapter while it is still able to charge at the same time. I can also just stream the video wirelessly directly to my TV by using standard protocols which Apple does not support.
I'm sure law enforcement loves this. While they may not be able to force someone to give up their password, getting a fingerprint is easy.
Actually it is being rather optimistic in its estimate. It's assuming driving 55MPh with the cruise control on (where it reports 60). I get 50 with the EPA estimate, which is also a little optimistic so realistically I get a bit under 50 miles of charge with everyday driving which is about 60% highway, 40% city streets. 19kw will not propel the car for normal driving. The 50 miles is taking into account regenerative braking as well. Yes, you pick up energy going downhill, but it doesn't match the extra energy required going uphill. Then there's also the safety issue of hauling a trailer. Here in California the law is vehicles hauling a trailer are limited to 55MPH. Then you also have a thick cable that would have to plug in to the side of the vehicle and go to the trailer. Then there's also the safety issues of hauling a trailer around, especially when you have a car that goes 0-60 in 4.2 seconds and can brake from 60-0 in 108 feet. I don't know about you, but I certainly don't want to have to worry about a trailer behind me nor would I want to be limited to 55 when on many interstates the speed limit is 70. Charging at the super chargers is not an issue. Yes, it adds some extra time, but not a huge amount, especially when you consider it's free. Spend the money you would on gas getting a nice meal, or do a battery swap if you're in a hurry. It takes around 90 seconds.
I have an 80A 240V charger at home and the car reports the charging rate based on that. It is more like 50 miles of range per hour of charging. Plus if I haul a trailer around that will significantly reduce the range due to the added drag and friction involved, reducing the range further.
I agree, the Prius is rather ugly, though not nearly as bad as say the Leaf. I say this as a Prius owner who now drives a Tesla. (My Prius is very rarely driven now, not since June).
0 - 32F should not have a huge impact on range, maybe 20-25% with the Tesla. After all, they are pushing heavily into Norway. For heating it uses a combination of heat pump or resistive elements depending on what is needed so it's not nearly as bad as the Leaf, which only uses resistive elements from what I understand.
I have had no problem with road trips with my Tesla model S. The Supercharger network makes them quite doable. My last trip was from the Bay Area up to Lake Tahoe (destination at 7200'). Admittedly while it's a bit under 250 miles, I went from near sea level to 7200' and it was over 100F for much of the drive. I stopped in Folsom to get lunch while charging (for free). By the time we finished our burgers the car was ready to go.
Right now the biggest limitation is waiting for Tesla to further build out their Supercharger network. Apparently they have all the equipment and everything lined up but most of the delays are due to city permits. In at least one location in Texas they were prevented from installing one due to the local representative being in the pocket of the car dealerships. They are expanding their network so in the near future this won't be an issue for me.
Also, in the near future they will be offering battery swapping when driving down to Los Angeles where the delay is just over 90 seconds to swap out the battery with a fully charged one. On the return trip I will end up with my original battery back.
The Nissan Leaf is a different story. I have a good friend with a Leaf. Even for trips around the Bay Area he is always having to stop in various places to charge due to the car's limited range. To make matters worse, since Nissan doesn't have adequate cooling of their battery using the ChaDeMo chargers is hard on the batteries and the batteries lose capacity quickly in hot climates. Right now I would recommend not buying a Leaf. Lease one and wait until they improve their battery technology in the next year or so.
The J1772 connector is not really capable of running an electric car even at 240v/80A (19.2KW) at freeway speeds. If things ran at 100% efficiency it could produce 25.6HP.
There are advantages and disadvantages of 64-bit mode. In the case of ARM, having double the number of registers should add a noticeable improvement. The main disadvantage of using a 64-bit ABI is that now pointers consume twice as much memory and in the case of RISC processors, loading 64-bit constants into registers can take more instructions. There is ongoing work with ARM to provide a 32-bit ABI using the 64-bit mode, much like how MIPS has the N32 and N64 ABIs (most of my experience is with 64-bit MIPS but much of it applies to ARM). In the case of ARM, having twice the number of registers should make a noticeable improvement since unlike X86 most instructions don't operate on memory locations directly except via load/store.
One weakness of 64-bit ARM is the instruction set is very new and the tools are still maturing. It was not necessarily the best thought out instruction set either and the instruction binary encoding is overly complex, making a lot more work for the toolchain developers. The difference between ARM 32 and ARM 64 is far greater than the difference between X86 and X86_64.
I learned long ago after some close calls to back everything up. In my case for my desktop I store my data on a XFS partition stored on a RAID 5 hard drive array. I also am using Crashplan to back up all of my data, both to a removeable hard drive and to the cloud with over 3TB of data backed up. The nice thing about Crashplan is that it continually backs up, taking periodic snapshots so I can restore a previous version of a file if I wish. The main drawbacks of Crashplan are that it runs on Java and can be a memory pig. I pay $6/month for unlimited backup of up to 10 machines and have several computers backed up with them now. With the proper settings on my router I don't even notice all the backup traffic running in the background.
Since I have had sudden SSD failures in the past I also dump my root XFS filesystem weekly onto my RAID array (it takes under a minute to run xfsdump) and incremental backups nightly and those dumps get backed up on the cloud as well.
I have found the XFS tools to be quite good at recovery when things go really bad. When running software RAID 1 I had problems where drives would drop out of the array for apparently no reason and I have had several occasions where while rebuilding the other drive would pop out of the array. Switching to an Areca hardware raid controller with battery backed DRAM ended those problems (besides seeing a big performance improvement).
I have found the RAID controller to work well when drive failure occurs and it even recovered after human error (I accidentally disconnected one of the active drives while it was rebuilding and reconnected it).
I won't use btrfs yet. The last time I tried it about 6 months ago it was quite slow and I have a lot of concerns about the storage filling up due to COW that have not been adqeuately addressed as far as I could tell. I tried setting it up for a Cyrus IMAP server on an Intel SSD and it was unusably slow just untaring all the files so I ended up going back to XFS.
SSDs are still relatively new. I have had issues with some firmware versions and had one fail catastrophically after only 2 weeks of use. I have also had compact flash and SD devices suddenly fail. My experience is that usually mechanical hard drives give some warning (i.e. SMART) and they tend to last years. I have a server I just retired where the hard drive had 10 years on the clock according to SMART.
As the owner of a Model S I looked in to the battery longevity. The battery pack should be good for a minimum of 8 years and likely considerably longer. From what information I have been able to gather, the cells are good for 3000 full charge/discharge cycles. Being very conservative and giving 200 miles of range per full charge (which is usually a fair amount more) that works out to 600,000 miles.
Plus it has been shown that replacing a battery pack is trivial with an automated system that can replace a battery in about 90 seconds.
The maintenance should be considerably less. The motor won't need an "oil change" for 12 years according to a tech I spoke with at the factory. Tesla has also stated that their goal is to not make a profit on service and maintenance, which is a far cry from the dealerships.
Right now the only way to buy a Tesla is online through their web site. It was a far more pleasant experience than dealing with dealerships trying to get a car in the color with the options I wanted then having to haggle over the price.
The maintenance schedule suggests taking the car in once a year for service. The warranty covers everything, including wiper blades and brake pads. Brakes shouldn't need service since they're hardly used. About the only thing they have to do other than inspections are to rotate the tires, change the cabin air filter and the wiper blades. The only other part that might need servicing periodically is the lead-acid 12v battery.
There are far fewer things to go wrong mechanically with the car considering that there's no transmission (just two gears with a 9.71:1 gear reduction) and an induction motor. As it is, the entire drive assembly can be easily removed and replaced (it takes them under 5 minutes to bolt the whole assembly in place at the factory). There's coolant, but it probably needs changing far less frequently. The AC should be a lot less prone to leaking since there's no engine mounted compressor with flexible hoses. There's no spark plugs, oil pumps, fuel pumps, fuel filters, air filters (other than cabin), EGR valves, oxygen sensors, catalytic converters, etc to wear out. Similarly, there's no oil changes, problems with warped heads, valves, camshafts, piston rings or all the other parts that wear. The only thing that can basically wear is the differential and bearings and the standard suspension stuff.
Dealerships are just a way to insert middlemen where they're not needed, and they're a monopoly by design. Usually you can't put in a competing dealership within a certain distance of an existing dealership unless they sell a different brand of car. That gives dealerships a local monopoly.
I disagree. It will cause fewer problems when having to resample. For example, usually DVDs and blu-rays require a 48KHz sampling rate. The additional bits and bitrate are also useful when mixing or processing the audio later for those who choose to do so.
According to a talk I attended given by Elon they use their own chemistry (LiCoAl). They are also automotive grade and are not the same as the consumer cells. Apparently Tesla can also use other manufacturers if needed as well.
Yes. Each cell in the model S is around 3.1Ah which is pretty high as far as energy density goes. Panasonic has some new cells that are even higher (3.7Ah) though it may be some time until they are qualified or deemed reliable enough to use in a car.
Their battery packs are designed with little ones failing without causing any major problems.
No, the reason they use 7000 cells is for reliability and cost. Other car companies use much larger cells, however the cost for those larger cells is high and the energy density is a lot lower than what Tesla is doing.
The batteries have to be reliable and not catch fire or explode. In the case of the large cells most car manufacturers use, they use a very safe chemistry. The drawback is that the energy density is a lot lower and the cost is high. Tesla went a different route. They chose the 18650 cell for cost and safety reasons. The Tesla battery pack is designed so that if a cell explodes it doesn't cascade into other cells or cause the battery pack to fail. Tesla has a much higher energy density than other automotive battery packs out there and it has been estimated that they also have the lowest cost as well for that density, estimated to be a fraction of what Nissan is paying for their Leaf on a per-kwh basis.
Tesla's 18650 cells are different than the cells you see on Amazon. For one thing, they do not have the protection circuits built in. The protection circuit is for each group of cells in the pack. Second, they lack the bump on the positive terminal since a wire is welded to the positive terminal. Tesla has done a lot with the cell design to minimize the cost. While it is the same form factor as a laptop battery it is not the same. The chemistry is also a bit different in order to be suitable for an electric car.
It has been estimated that Tesla pays under $2 per cell but nobody except Tesla and Panasonic know the actual cost. Tesla also gets the economy of scale. They go through 3-4 million cells per week acording to one of the techs I spoke with at the factory.