Posted: Sat Jan 22, 2011 1:50 am Post subject: ATTO Disk Benchmark 74GB Raptor w/Supercache +works for SSD
Supercache with 512-1GB worth of RAM can improve the read speeds on a SSD and HD by unreal amounts for ATTO Disk Benchmark. HD's still suffer from the problem of access times, but SSD's don't have that problem. Also write speeds can be improved a lot as well if you turn on differed-write mode and suspend lazy writes, but a UPS is pretty much required for that or you risk losing data if you have a power outage not sure if that applies for SSD's though since they are non volatile.
For the best results 128-256KB cache page size and 512MB-1024MB cache size is ideal on a HD. For SSD's I found 64KB cache page size to be optimal with 352MB cache size ideal on the 32GB SSD I tested.
Oddly it only seems to help ATTO Disk Benchmark, but HDTune it doesn't appear to effect, but I'm not sure why that is. It's peculiar since RAMDISK's work with HDTune and supercache is basically a hybrid of a HD/SSD and RAMDISK kind of like these WD HD's are a hybrid of a HD and SSD.
Last edited by inmani on Wed Feb 09, 2011 5:15 pm; edited 1 time in total
For reference in the picture differed-write mode and lazy writes weren't turned on in that comparison because that test was using a 74GB raptor and I don't have a working UPS right now so not gonna risk turning that on for continuous use for that drive, but I could have turned it on for the test and write times would have substantially improved as well.
Here's one of a SSD I tested using it which had those settings on I figure since SSD's are non volatile it might not matter about the UPS for them with those settings though not 100% certain on that I'll probably find out later through testing eventually though.
Anyway as you can see the write speeds and read speeds are through the roof in this test with Supercache and it was only using 352MB worth of system RAM. The SSD used was a ADATA 32GB rated at 230MB READ/60MBWRITE.
I experimented more on a few different hard drives and types of hard drives rotational, SSD, and USB flash drives.
Using CPU-Z and looking at your CPU caches tab I found taking your cache size L1 width (32kb) and multiplying it by L2 being optimal if you have a L3 you'd use that rather than L2.
12MB L2 x 32 = 384MB and since it's 8-way I set my read ahead to 8 because it just seemed like it would sync perfectly rather than being async which is generally not ideal.
Fancy Cache I haven't tried, but is pretty much same type of program and I think would be optimal in the same way.
I didn't find any tangible benchmark improvements beyond 384MB caching for my setup, but below it it seemed to gradually trail off a bit sometimes more sometimes less depending on how it was set. It was still a marked improve though over no caching at all mind you.
This is totally worth doing if you have the ram to devote to a small cache on your drives it'll make them much more responsive in general.
I think this is exactly what SSD companies have started to do with controller caches on SSD's to speed up both I/O and raw bandwidth a lot though they needed faster SATA protocols along with more cache as well, but this is why SATA protocol hasn't really kept up it's light years behind curve in terms of where it should be because prior to SSD's traditional HD's couldn't saturate them anywhere close to the same way w/o resorting to unconventional raid-0 implementations.
I pretty much saw this coming with solid state devices for few years. This is why they are more and more switching to PCI-E and not just to power the device, but actually using the PCI-E lanes themselves now since SATA is too saturated. This is also why a bit of a mild PCI-E overclock which OC's SATA controllers as well will boost SSD performance SATA is bottle necked.
I'm really disappointed that there isn't any GPU VRAM volume caching software though Linux has a GPU ramdisk unfortunately no one's made one for windows which is silly. The bandwidth of GPU's and VRAM on them these days would make drive speeds insane they are even faster than system memory. ATI and Nvidia are sleeping on a great potential market avenue who doesn't want a faster more responsive system.
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum