Double post
Double post
Some tests on what I have access:
V3 120GB @ SATA3 - light server: Average 501MB/s, minimum 431MB/s
V3 240GB @ SATA3 - light server: Average 491MB/s, minimum 438MB/s
V3 120GB @ SATA2 - desktop, with 17GB of static incompressible data: Average 262MB/s, minimum 237MB/s
From my tests, I would say V3 120GB models can sustain at least 262MB/s read speed with incompressible data, but no more than 450MB/s. 240GB model had a much stable output around the average speed so it might sustain more.
Last edited by sergiu; 11-13-2011 at 06:02 AM.
That depends on what NAND is used, async is noticeably slower than synchronous.
The Force 3 120GB (async) used in the Endurance test drops to ~190MB/s using incompressible data (e.g. MP3)
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Hardware:
The file system on the OS has a cluster size. For instance if the cluster size were 64k then writing one byte writes 64k to the disk. Does this mean it would be best to keep cluster size the same as page size?Originally Posted by Ao1
Let's have a look.
Unaligned reads @64k block size.
Aligned reads @64k block size.
The surprising one for me though is 4k block size.
Unaligned
Aligned
What happened to my 900MB/s read speed?
Last edited by some_one; 11-13-2011 at 07:40 AM.
The nice thing with HD Tune is that you only have to run the read benchmark to find out the compressibility of the data on your hard drive at any given time. For a single drive (with TRIM) you can also see how much data on the drive has been compressed. For example in post #118 I placed 35.81GB of data on the drive. The drive benchmark however is showing that only 26GB of NAND was used.
Anyone with a SF drive that has been using it for their normal activities only has to run the read benchmark with the 4MB block setting to see how much their data has been compressed and how fast their read speeds are likely to be in real life applications.
With regards to aligned vs nonaligned in real life nonaligned writes/ reads occur all the time. Obviously the OS will try to make them aligned, but that does not mean it happens every time.
With regards to larger drives I suspect that once everything has been written to at least once the results would be the same.
Maybe you hit some request limit.
How have you made HDTune requests to be aligned for benchmark section? Seems I'm not lucky in finding the option...
@Ao1
Indeed, I believe HDTune is a good indicator on how effective is compression
900MB/s = 230,000 iops, that would be rather amazing at 4KB block size using just a few drives.
I expect 900MB/s would be possible at 16-32KB blocksize.
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Hardware:
AFAIK that option doesn't exist, you would have to ask the author to provide it.
You're right Anvil, 16k gets me back to 900MB/s, 8k ~650MB/s but of course the drive isn't as fast as that when real data has to be retrieved.
Look for the Extra Tests tab
Just an FYI in case anybody else was hunting for information, it appears that G. Skill also applied the throttling to their SF1200 drives much like OCZ, it's mentioned in their firmware update releases (for SMART monitoring of throttling) and I'm pretty sure I just triggered it by re-building (and re-imaging over) a RAID array. Write speeds went right to hell, right now my 4-drive raid 0 is slower than a single drive in a lot of tests even though it's 4k aligned right.
*sigh* I think I'm done with dealing with this sandforce silliness.
Huh, shouldn't your drives have thousands of hours on them now given how old they are.
Writing a couple of TiB during imaging at that stage should not have triggered any form of lifetime throttling. Your problem is probably elsewhere.
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