Gigabyte's i-RAM: Affordable Solid State Storage
by Anand Lal Shimpi on July 25, 2005 3:50 PM EST- Posted in
- Storage
i-RAM as a Paging Drive
One question that we've seen a lot is whether or not the i-RAM can be used to store your pagefile. Since the i-RAM behaves just like a regular hard drive, Windows has no problem using it to store your pagefile, so the "can you" part of that question is easily answered. The real question happens to be, "should you?"We have heard arguments on both sides of the fence; some say that Windows inefficiently handles memory and inevitably pages to disk even when you have memory to spare, while others say that you'd be stupid to put your pagefile on an i-RAM rather than just add more memory to your system. So, which is it?
Unfortunately, this is the type of thing that's difficult to benchmark, but it is the type of thing that's pretty easy to explain if you just sit down and use the product. We set up a machine, very similar to how we would a personal system, but tended to focus on memory hogs - web pages with lots of Flash, Photoshop, etc. Of course, we opened them all up at once, switched between the applications, used them independently, simultaneously, basically whatever we could do to stress the system as it normally would be stressed.
At the same time, we monitored a number of things going on - mainly the size of the pagefile, the amount of system memory used, the frequency of disk accesses, pagefile usage per process... basically everything we could get our hands on through perfmon to give us an idea if Windows was swapping to disk or not.
The end result? There was no real tangible performance difference between putting more memory in the system and using the hard disk for the pagefile or putting less memory in the system and using the i-RAM for the pagefile. Granted, if we had a way of measuring the overall performance, it would have shown that we would be much better off with more memory in the system (it runs faster, and it is accessed much quicker than off the i-RAM).
The only benefit that we found to using the i-RAM to store our pagefile was if you happened to have a couple GBs of older DDR200 memory lying around; that memory would be useless as your main system memory in a modern machine, but it'd make a lot better of a pagefile than a mechanical hard disk.
One more situation we encountered that would benefit from storing your pagefile on the i-RAM was those seemingly random times when Windows swaps to disk for no reason. But for the most part, our system was slower when we had less memory and stored the swapfile in it than when we had more memory and less swap file.
Adobe Photoshop is a slightly different creature as it keeps a scratch disk that is separate from the Windows pagefile. We tested Photoshop and used the i-RAM as our scratch disk, but in all cases it always made more sense to just throw more memory at Photoshop to improve performance where we ran out of memory. If the operations you're performing in Photoshop can fit into system memory, then you'll never touch the scratch disk.
Overall, based on our testing, the i-RAM doesn't make much sense as a paging drive unless you have the spare memory. The problem with "spare" DDR200 memory is that it is most likely in small 64MB, 128MB or maybe 256MB sizes, which doesn't buy you much space on an i-RAM drive. For most people, you're much better off just tossing more memory in your system.
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Sea Shadow - Monday, July 25, 2005 - link
I wonder if the OS is the limiting factor. They should run some tests using other os *cough* linux *cough*.What would be really neat is if they could design an i-Ram device that uses 2 HDD bays and supported 8+ GB of ram and ran from a standard molex.
sprockkets - Tuesday, July 26, 2005 - link
You people think about using Knoppix and copying to the drive? For that matter, that and stuff like damnsmalllinux and such can be run totally from system ram.Instead of using this though for a slient drive, you are better off using flash memory drives for that.
ViRGE - Monday, July 25, 2005 - link
Unfortunately if they did that, it would mean that your computer could never be turned off. As noted in the review, the card is currently still powered even if the machine is "off", due to the fact that when a modern ATX computer is off, it's actually more of a super-standby mode that leaves a few choice items powered on for wake-on events(LAN/modems, and the power button of course). All Gigabyte is doing here is taping in to the 3.3v line on the PCI slot that wake-on power is provided through, which is enough to keep the device powered up even when the system is in its diminished state.Molex plugs on the other hand are completely powered down when the system is "off", so it would be running off of battery power in this case. A lot of us leave our systems on 24/7 anyhow, but I still think they'd have a hard time selling a device that would require your computer to be off for no more than 16 hours at a time.
Gatak - Monday, July 25, 2005 - link
They could use the USB power. On most motherboards you can enable with a jumper or BIOS to supply standby power to the USB. Often the setting is called "Wake on USB" or "Wake on Keyboard" etcreactor - Monday, July 25, 2005 - link
"What would be really neat is if they could design an i-Ram device that uses 2 HDD bays and supported 8+ GB of ram and ran from a standard molex."Was thinking something similar myself as i was reading.
I think once ram modules are 4gb or larger, then this could be very useful. But not until it gets updated with sata2, ddr400 etc. When the time comes to build an HTPC then ill give this another look.
Nice article.
ranger203 - Monday, July 25, 2005 - link
Not to shabby, but i was honestly expecting like 3 second boots, & 5 second game load times... why is there only a 20% speed increase in some areas?Griswold - Thursday, July 28, 2005 - link
Because the data still has to be processed after being loaded - bandwith is obviously not the biggest bottleneck here.forwhom - Tuesday, July 26, 2005 - link
What I would be very interested in seeing is the performance of the thing using it as the source for encoding a dvd/mpeg... Most encoders are heavily disk-based and if it could reduce the time significantly it might be worth while - assuming that eventually they come out with one big enough to hold the source. There's now reasonable CPU encode performance, just have to get the data to/from it... maybe the i-drive would help..highlandsun - Monday, July 25, 2005 - link
Hmmm, the WD Raptor has a sustained transfer rate of 72MB/sec. So on a freshly formatted drive, with no fragmentation, it should still be half the speed of the iRam. But at $200 for a 74GB drive, then you could get a pair of these running in RAID0, which would run at around 140MB/sec anyway, and still have spent less than the cost of the iRam and 4GB of DDR DIMMs. It definitely seems like this product falls short.The use of PCI 3.3V standby power is clever. Perhaps a future version should just use a dummy PCI card to provide the power, connected to a 5" drive-size case with many more DIMM slots. If you can't cram at least 16 DIMMs in there, then the ability to use old memory is kind of wasted, since the old modules will have such small capacities.
Ultimately I think this type of product will always be a failure.
What they should do instead is make it a pass-through cache for a real SATA drive. So you plug the SATA controller into it, and plug it into a real SATA drive, and it caches all I/O operations to the real drive. That's the only way that you can get meaningful benefit out of only 4GB of memory. A card like this would turn any SATA drive into a speed demon; 4GB is definitely a decent size for most caching purposes.
highlandsun - Monday, July 25, 2005 - link
Of course the next logical step is to put the DIMM slots on the SATA controller card, so that access to cached data occurs at real memory speeds, not just SATA bus speed. This would only be a useful product for folks stuck on 32-bit systems, because otherwise it would be best to just increase the system memory instead. But there are plenty of 32-bit systems out there that would benefit from the approach.