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Linux On Solid State Disk
Blah writes: "A while back Slashdot made reference to The Platypus Solid State Disk. The boys down at LinuxWorld.com.au have scored themselves one and given it a look over. The article has some pictures showing just how much SDRAM this thing has on it, as well as graphs which compare its IO and transfer rate performance against that of standard SCSI disk."
I don't think he's talking about systems actually required for flying the plane - things such as targeting systems (where information on which locations are planned targets could be valuable to the enemy) or map data (which would tell the enemy how much of their defense system has been located) would be more likely candidates for such treatment.
Then again, it could just be that the Air Force doesn't like sharing its sooper-sekret pr0n files with anybody else.
The US Air Force uses solid-state disks in at least some of its aircraft. They load the software right before takeoff. The idea is that, if the plan goes down or is captured, the pilot just has to power it down and all the software is lost, and then the plane is useless.
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Napster-to-go says "Fill and refill your compatible MP3 player", which is a lie. It's not MP3. It's WMA with DRM.
Why didn't they make this an AGP card? It's a dedicated port designed for fast I/O. I know that AGP is the reincarnation of VESA, but does anyone know any reason why this wouldn't work?
that they're talking about military things, do you? "I've got the ball" indeed....;-)
Vintage computer games and RPG books available. Email me if you're interested.
> A high percentage of my working day is spent waiting for compiles, as even a single change to a file requires on the order of five minutes of compiling and linking. A lot of that is file read/write time. If I could write it to memory-speed output rather than disk, I would be a happy man
Uh ? Put more RAM. Put even more RAM. And some extra RAM. Then use a ram disk for your object directory, and keep a lot of ram as the file cache. On a bsd, suppress atime update on the directory containing system include/libraries, or mount it read-only or copy it into a ram drive. Remove atime from you sources too.
> According to the task manager
Oh, I guess what your problem is. You use an OS that have a journaled meta-data filesystem (so sloow sync write for each file) and that have *very* high fragmentation (spend most of his time seeking).
Cheers,
--fred
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Bottom line is that you need to use the right tool for the job. Sometimes it's a SSD, sometimes its real disk.
Don't forget that ram disks generate less heat and use less power and have no moving parts compared to a drive array.
Quantum has had solid state drives for almost 4 years now. They pioneered the field and their scsi SSD's blow the doors off anything out there. And with an added benefit, it's native scsi, no special drivers needed, access times in the 50ns range, as opposed to the standard 5-7ms for even Cheetah drives.
"See, we plan ahead! That way, we never have to do anything now."
You are missing two things: speed and volatility.
1. SPEED: A Solid-State hard disk is made out of static RAM (SRAM) not the dynamic RAM (DRAM) that consitutes the user RAM in a PC. SRAM is what is used in on-chip cache and is MUCH faster than DRAM because it stores information actively and has physical amplifiers in each memory cell (usually SR-latches), rather than passively storing the information on a capacitor as in DRAM. Because of this it is also much more expensive and burns more power than DRAM. That is why these solid-state hard disks are so expensive.
2. VOLATILITY: When your computer crashes, or you shut it down, your RAM disk is GONE. This means you have to periodically write it to a physical hard-disk. With a solid-state hard disk, it looks to the computer just to be an amazingly fast hard drive, and no memory-management overhead is required. This is a big deal to large data warehouses and data mining operations.
The real selling point to the solid-state hard drive is the speed. Internal SRAM can operate upwards of 1 GHz, and although it can't communicate with the outside world at that speed of course, with advanced high-speed digital signaling technologies you can achieve latencies and throughput unheard of with regular hard-disks and even DRAM based RAM-disks.