RAM Disk Puts New Spin On the SSD
theraindog writes "Although the solid-state storage market is currently dominated by flash-based devices, you can also build an SSD out of standard system memory modules. Hardware-based RAM disks tend to be prohibitively expensive, but ACard has built an affordable one that supports up to 64GB of standard DDR2 memory and features dual Serial ATA ports to improve performance with RAID configurations. And it's driver-free and OS-independent, too. The Tech Report's in-depth review of the ANS-9010 RAM disk pits it against the fastest SSDs around and nicely illustrates the drive's staggering performance potential with multitasking and multi-user loads. However, it also highlights the device's shortcomings, including the fact that SSDs are more practical for most applications."
Without RAM, this costs $380 which is probably more than double the RAM itself if you don't use anything to extravagant. I know other companies offered these in the past, with the similiar high price, always to act as a harddrive with a battery for backup. It was always easy in linux to make a portion of your memory act as a ramdisk, however many motherboards often didnt enough ram slots to make it appealing to split memory up like that.
I wonder if a company like Apple can instead, on its laptops for instance, just move to SSD for its laptops since they are becoming seemingly cheap, exclusively (for OEMs) license a technology like MFT, and get a real speed edge on other makers. I think it would make more sense than a ramdisk where the bandwidth of ram vs the hard drive channel seems overkill.
so, this is just as worthless as Gigabyte's i-RAM.
1993 was fun. A few buddies and I built out a hardware ram disk with an unused 486 and some serial cables. Granted, it didn't come in as a native HDD, or even as a linux file system, but we built a little API that made it work reasonably well in software with standard file operations and even a crappy little "directory" structure. It worked fairly well... for some reason Mondo2000 pops into my mind.
meh
This seems like it would be an excellent solution for a swap drive and for a c:\temp or /tmp directory.Fair enough as swap *nix OSes will reap little benefit, but Windows seems to hit swap no matter how much RAM you have so there should be some significant performance gains there.
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Skimming the article, I'd summarize as follows:
Real world performance not radically better than fast traditional HDs or SSD solutions, and you can't power off your PC for the night. (Unless you backup to flash every night.)
I'd say this is a niche product, but could be a very good one for a chosen few applications.
.: Max Romantschuk
It seems that with a little firmware it could be coaxed to do some content addressability. Considering that it is 10x faster inside than the peak of the SATA interface. It seems to me that there is a lot of potential. I always liked the ram disks when they were popular ISA cards and this could be the thing that could use the full power of USB 4.0 [sic]. Applications could be changed to take advantage of this speed. If lists and SQL databases could be sorted on the drive without CPU overhead, it could be very useful.
"However, it also highlights the device's shortcomings, including the fact that SSDs are more practical for most applications."
I'm sure that there is some sort of typo somewhere. Since when is being "...more practical for most application..." considered a shortcoming?
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woa is the day you have a 64gig hdd made up of ram sticks and one goes bad....happy hunting grasshopper.
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Yay, a RAM HD! I'd like to see the pagefile dig into this - Microsoft must be foaming at the mouth. Sorry if that seems like trolling, but I've had it up to here with the constant and painful HD thrashing that Windows always seems to enjoy doing (and probably their less than perfect implementation of it).
Why OpalCalc is the best Windows calc
In the real world benchmark, the only place where it shines is during file copy operations. It's on par with Intel's SSD when measuring OS load time, game level load times and other application benchmarks. The battery only hold 16GB for 4 hours too, you'll need that CF card to backup to (which is a neat feature, just the press of a button to backup and restore). Any way, I'd gladly take it for free.
Isn't it better (easier, faster) to just put 64 GB of actual RAM into your system (and if needed use part of it as a ramdisk), and using a normal drive for storage? You could have an enormous amount of disk cache!
Would you rethink your definition of fail if they were using a Sony laptop battery?
I can't see why I'd use this rather than just putting more memory in my machine...
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I have a high-load mail server that uses a 2G RAM disk (a Curtis Nitro!Xe) for the queue. It looks like a normal 3.5"/1" high SCSI drive with a SCA hot-swap connector. It was made before high-density CF cards, so it has a 2.5" notebook hard drive inside for storage after shutdown (it has a battery to start the drive, dump the RAM, and shut down). We've had this in service for almost 5 years, and it has really made a difference.
The point to a RAM disk is not necessarily bulk data throughput, but I/O operations per second. Mechanical drives are limited to 100-200 random IOPS or less, while the RAM disk can easily hit 100,000.
Any drive can fail, that's why you do backups. Maybe put them in RAID-0 and pray the batteries don't all go :). At least rebuilding would be quick.
My university used RAM disks back in the day - it was the only way to get decent performance on older machines. The computers didn't even have hard disks in. My brother (who went to the same university) has a story where he sped up his large FORTRAN compiles by a factor of 10 just by working out how to use the RAMDisk (which was only ever used by the PXE-style boot procedure and then hidden from the OS) for his own purposes and people couldn't work out how he was doing it because he still took stuff home and brought it in on floppy. This is a nice hark back to those times.
The killer, however, is the price... the price of a PC, basically, before you add the RAM. If you're REALLY serious, you'll have machines that can just take the extra RAM directly and do this in software. If you're not willing to pay that much, well, nothing will work for you but a few bits of extra RAM and a fast SSD for the same price won't go amiss. However, if you occupy the middle ground... this still doesn't seem worth the effort. It'd be cheaper to just buy an SSD, some extra RAM for cache and maybe even a cheap PC to throw it all in (if NanoITX supported 8Gig chips, this device could almost be made obsolete overnight).
The interconnect too - yes, it emulates a SATA drive but it emulates two as well and fails to do anything significant with them. So you'd need a RAID0 setup, with independent SATA setup, and an expensive device, with lots of even more expensive RAM just to be a fraction of a second quicker than an off-the-shelf SSD in the same machine. The people for whom it's worth it won't want to be bothered with all this.
The CF Backup feature is fantastic. I love the idea. But 20 minutes is a long time to wait if the battery is only four hours worth when it's brand new (four hours? At least 24 would have been useful and given you a chance to actually do something with it). You would want to be backing up anything this thing held anyway, so you don't really gain anything because the CF is the most inconvenient backup because of its manual nature.
I can't see a situation where 64Gb of fast storage is worth that amount of money + time + hassle + 64Gb of RAM + potential firmware problems + interface cabling + ... The bottlenecks in anything serious are going to be elsewhere.
First of all, I absolutely love these devices. It's a great idea that's been well executed, and yes, they're a niche product, but we've one or two apps that would notice the increase in speed from these, and if I had the money I'd buy a whole bunch of them to stick in our servers. ... except that you don't get 5.25" bays in an awful lot of modern rack mounted servers. Certainly none of our new kit has them; all that space is taken up with hot swap 3.5" or 2.5" drives.
And that's what kills it for me. Even if I'm looking at a new server I'd have to make sacrifices to fit one of these. My first choice for a new storage server is going to be one with 24x 2.5" drive bays. I'd have to sacrifice a full 8 drive bays to make room for one of these, and it's just not worth it. Not when I can buy an Intel SSD for the same price, loose just one bay, and have it hot swap to boot.
And even worse, there are PCIe devices just around the corner, with 3-4x the read and write speed of any SATA device. Those will drop straight into any of our current servers, no problem at all.
So unfortunately, much as I love the ANS-9010, I just can't see any reason to buy one :(
How does this thing handle getting the power cord yanked in the middle of a large write operation?
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"I'd bother, because most of *my* tasks are disk I/O bound"
I totally agree. For some tasks its very useful. (If we had memory that was the speed and no write deterioration like it was DRAM, but non-volatile like Flash, then that kind of memory would make this DDR2 based product obsolete, but until that time, its very interesting. Maybe there's hope in time for Memristor based memory, but for now this product does have some advantages).
I was interested in Gigabyte i-RAM but its too limited at only 4Gb.
I have wondered how practical it would be to create an open hardware project like this product, based around FPGA and DDR2 (or maybe DDR3 as that will likely be cheaper within the next I guess about 18 months and taking over from DDR2). Does anyone know of any existing open projects like this?
There are 10 kinds of people in the world... those who understand binary and those who don't.
Compare 350$ (device) + 300$ for memory for a 32GB drive versus 4 x 600$ Intel SSDs.
I got one of these in our lab, and can answer questions on it. Had both units... the 6 slot version and the 8 slot version. This thing is the spiritual successor of gigabytes's iRAM. It takes bog standard DDR2 RAM as storage and lets you connect it as a SATA drive.
A few of the things it improved on the old iRAM.
*DDR2 supported ram, with 6-8 slots, taking up to 4G sticks.
*A fair sized battery.
*A CF backup slot.
*RAID friendly, multiple SATA ports on 8 slot model.
*Uses 5.25" bay rather than PCI slot.
*ECC
First off, no special device driver was needed - the drive was OS agnostic. Every mainboard and controller card I used saw it the device like any other SATA hard drive you might plug in.
The RAM slots take bog standard DDR2 RAM. The documenation mentions speeds of 400/533/667/800 are all supported. Benchmarks with 533 and 800 grade RAM produced identical benchmarks, so faster RAM does not appear to have any impact. I also mixed and matched faster and slower DDR2 modules without issue.
Just like most mainboards, the RAM needed to be installed in pairs if over one stick was used.
Unbuffered ECC or non-ECC modules are both supported. Registered RAM was not. I tried to pull eight 4GB sticks from one of my Sun boxes to give the 'full montey' test. No joy. Had to stick with the far cheaper RAM.
There was an interesting option for these who wanted to have ECC but used 'regular' non-ECC RAM. Eleven percent of the memory could be reserved for error correction. Again, all hardware based - just move a jumper. Performance metrics between ECC and 'simulated ECC' had negligible differences.
The 8 slot model has two SATA ports. By setting a jumper, you could have the entire RAM capacity as one large drive on one SATA port or split it as two independent drives. If you splid the drive you had to have an even number of RAM sticks installed. Another jumper would dumb the interface down to SATA1 speeds rather than SATA2. Never tested that....
Did test RAID-0, however. (grin) The synthetic benchmarks don't hit this device's sweet spot - database usage. Reads are fast. Writes are just about as fast. The RAID controller really makes a difference, as my 3Ware card performed significantly faster than with the mainboard based RAID. Using a EVGA 780i mainboard, it was not crushingly faster than a trio of velociraptors.
For anyone who has installed XP, you know the wait between hitting the 'workgroup' and the first reboot? Just over two minutes. By far the fastest install I've ever done. The OS also started faster than any other disk or SSD system I've used.
The CF bay was a nifty option. The question came up - what if I want to shut my machine down overnight? You can. If you have a CF card with more capacity than your RAM, it will back up the disk image automagically. You can also push a button to back up the current 'drive image' to CF, and another to restore the image. (I was able to go back and forth from Linux and Windows very easily).
Anyhow, tis a fantastic high speed scratch disk or OS disk when write speed matters. For those of us who already maxed out RAM, this covers the gap between RAM drive sharing RAM with the mainboard and fast disk.
+++ UGUCAUCGUAUUUCU
Get the device down to about $50 and I'll think about buying one. I don't see any reason a device like this is $380. That's just crazy.
bork bork bork!
Maybe if the battery life were longer than 4 hours, I'd be willing to overlook the fact this thing is based on volatile memory. But if I can't even shut down the machine overnight (and it takes ~15 minutes to restore 32GB from flash) then AFAIC this "SSD" is strictly a novelty.
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With this, we'd also be lucky enough to lose our data too
That's why it has a CF slot. Leave a CF card in the slot, and if the shit hits the fan, go press the "Backup" button, which will take less time than your UPS' power.
Ah, Amiga old buddy, I miss you.
This sound's like DKB's Battdisk. Next to a Video Toaster and SuperGen, the Amiga 2000s best friend. It took a machine from the slowest booting system in the age to the fastest.
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That is pretty mediocre.
For DDR2, maybe, for fixed disk usage? Still pretty good compared to spinning disks or even flash.
Of course, RAM disks are not anywhere near new. I remember looking at one a while back that used plain old SDRAM. That's a bit hard to find today; it's often actually cheaper to get DDR2 today than DDR. In higher capacities as well.
Of course; this brings up the question of 'what's the use?' - Seriously, unless you have something weird going on, just install a 64 bit OS and put the extra memory directly into your system.
Looking at all those benchmarks; except for the most artificial disk-thrashers; benchmarks for all were within 1-10%. Lost looked to be less than 5% difference between max and min.
I don't read AC A human right
At the university we've been playing around with a new storage system that has ridiculous capacity and speeds. It uses 120 1TB drives to create a striped 100 TB storage system with redundancy. Fast writes are made through the interface directly into the RAM for one of the control computers. These computers each have 32GB of RAM and write the data onto the hard disks over a longer time than the initial dump to memory. You can get effective transfers up to 10 Gbps through the fiber channels. The best part is that this system uses off-the-shelf components with a custom build of Linux to handle IO. It appears as a standard high capacity network drive.
You can get devices like this for at least a decade, possibly much longer. The primary advantages of FLASH are low price, high reliability and battery-less non-volatility.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
It takes one bay for the RAM drive with built in battery, but they could have an additional full drive bay expansion battery with a jumper cable connector to give it a much longer hold time with the machine shut down.
I'd use this for some of the math research I do. I currently run something for hours at a time and could save to disk every couple hours. If the computer were interrupted mid cycle, it would be garbage anyway.
Random reads *and* writes would be super fast. I imagine some guys working with video would love this.
I also wouldn't mind having my games on RAM so everything loaded 20x faster.
t
What does battery filure leading to total data loss have to do with it being a solid state device?
When I was a poor, poor college student (not much different now, actually) I had a RAM drive in the 386 I cobbled up. Even a 10meg hard drive was prohibitively expensive, but I had memory. So, I set up a 3.5" floppy to create a ram drive on boot up, copy Procomm plus and text.exe into the RAM drive. Then I could log into GEnie and copy data. Typing "exit" saved my data and allowed me to power down. Oh, the job of batch files...
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Bandwagon jumpers are not welcome among real Mac users. Keep your filthy PC fingers to yourself.
Did you just find the "Any Key"?
I have a key combination for you. It'll tell your computer to work for you while you just sit there and collect money. Just press the Alt key, Ctrl key, and Delete key all at the same time!
mOOF
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Not knowing anything about memory buses really makes this hard to comment, but I'm pretty sure you need lots of pins to interface memory.. And you need space on the motherboard, also such a motherboard wouldn't be massmarket. All these things costs lots of money (and is available for large quantities of money).
This solution is beautiful because it's simple and inexpensive ($200 for 16GB), max costs is 8x4GB modules.
Though I think you have a point that there should be a new class of I/O interface that can handle these types of disks better. Perhaps as tiered memory, where some of it is slower than the rest.
$200 is just for the memory, sigh..
Cool thing is you can cold boot memory from these as well, so back when you needed to reboot your computer because of memory corruption you could boot really fast by using ram disk..
I don't think "solid state" means what you think it means.
Seems simple for me really, .tars and writes back to the SSD. I was going to re-write(engineer) the app to use memory caching but this would be simpler, and so is what I'm going to do.
I boot from SSD and all my files are on SSD. This is scratch disk for the gob of small reads and writes my system does (connected to some lab hardware), when a job is done it
-nB
whois gawk date unzip strip find touch finger mount join nice man top fsck grep eject more yes exit umount sleep dump
Which ofcourse isn't really an option anymore when your talking about a server which is not constantly being monitored by someone close enough to hit the button or for any site with more the a few servers.
It's fine however as boot disk containing static data. You know, the kind of stuff you'd restore from a disk image anyway. If you want fast booting servers, or something to serve your static data really fast this might be an option.
well i pass your test, but i'll go ahead and still GTFO. MACs are for trolls (evidently)
When PCs were still young there were add-in cards for memory, I still have some of these dinosaurs laying around. Certainly it makes sense that daughter boards could be made to create RAM disks that just plug into an empty slot on the PC, or in a case with some really wide and fast pipe for a laptop.
Most of the posts say what's the point, I'd rather stuff it into my regular RAM.
ZFS could use something like this for the ZIL/etc if it's faster then existing drives.
Battery backup means it keeps the content. Can it flush the ram to flash when the power goes out? Then load it back into its ram when the batt. is back up. That'd be perfect! No wear on the flash + protection from power outages.
Hey, my PCjr had a RAM disk. Worked pretty damn well too. I guess good ideas never stop working!
I'm a 2000 man.
DRAM loses it's data when power is switched off. Battery backups and other fail-safe features designed to keep data persistent in DRAM based disks might be considered too risky.
If your computer is off and the battery backup fails - you will have a freshly 'wiped' hard disk within a few seconds/minutes.
Which is why DRAM 'disks' are only really good for temporary data - like your download of the specification for a DRAM 'disk'.
Her lips were softer than a duck's bill, but her quacks
This is still just RAM pretending to be a hard drive, SATA in this case...
Let me know when they produce a NAND based flash memory card that plugs directly into the PCI bus for ridiculous IOPS...
Oh, wait... they've already done that... it's called FusionIO...
FusionIO is the only real SSD solution right now if you need to push > 80k IOPS.
These aren't the cheapest things out there, but if you run large databases and need to get your database to actually be per formant... an array of these is the way to go.
A bunch of ram pig-tailed off of SATA is just horrifically slow in comparison...
-- Dave
up 12 days, 22:30, 2 users, load averages: 993.20, 994.21, 994.56
*makes note to limit user processes...
You mean the FusionIO {drool} isn't the most expensive thing out there?
The cost of that cleanup, of course, will be borne by taxpayers, not industry.
Ideal for developers who work on huge projects. You can put all your .o files and the compiled binary on the RAM disk and the compilation/linking performance should be marvelous. And if there is a power failure, you can always just recompile everything. I will seriously consider getting one of these...
At least they aren't until you put 16 cores in one box and share the I/O across all the cores, running 40 p2v servers.
Then all tasks are I/O bound. 1/16th of a 4Gbit SAN connection is 32MB/s. 1/40th is 10MB/s in practice. That's sad. That's 1980's I/O.
Why bother?
1. Money.
2. Desire to excel.
Why bother to do anything, really?
Help stamp out iliturcy.