Re: Consumer-grade vs enterprise-grade disk drives

Jeff,

> If we're looking at the same benchmark (File Server DriveMark), the
> fastest SCSI disk is 65% faster than the fastest SATA disk. The fastest
> SCSI 10K disk is 25% faster than the SATA.

I think it's misleading to compare drives on the basis of one benchmark.
One of the things I like a lot about storage review is the "Head to Head
Comparison" feature. If you use that, you see a completely different story:

http://www.storagereview.com/php/benchmark/compare_rtg_2001.php?typeID=10&te
stbedID=3&osID=4&raidconfigID=1&numDrives=1&devID_0=237&devID_1=263&devID_2=
259&devCnt=3

In particular, that the 2004 era Raptor is somewhere between the fastest 10K
RPM SCSI drive and the fastest (2005) 15K RPM SCSI drive on all but the
tests where TCQ is dominant (the two server quite benchmarks).

So, if you are doing high concurrent random IOs, you will still prefer the
more mature TCQ support in the SCSI drives. If you are doing large block
IOs, you will favor the SATA drive for it's faster transfer rate/RPM/$.

In the words of the editors in June 2004:

" In the end, the potential for SATA to invade the entry- and mid-level
server market is there. The performance is definitely there. If the Raptor's
reliability proves comparable to the competition and if the
infrastructure/support hardware surface, WD will have a viable contender."

> The 3Ware controllers are probably the worst ones you can get for
> database use. Their caches are slow (I didn't even know that was
> possible until I bought one), as are the XOR engines.
>
> After reading this very comprehensive benchmark:
>
> http://print.tweakers.net/?reviews/557

Great review - thanks for the link. I'm not seeing as harsh a conclusion
about the 3Ware 9500 adapter as you - in fact, it's at the top of the IO/s
on IOMeter Fileserver simulation and it's in the pack toward the top on most
all of the other benchmarks. The only benchmark it lags significantly on is
the RAID5 write test, which correlates with your point about a slow XOR
engine.

The Areca definitely looks to be the fastest with the highest scaling, but
not the fastest at writes either (#3 out of 7, the 3Ware is #4 out of 7).

> I purchased one of the Areca controllers with a large battery-backed
> cache. It is unholy fast. I recommend it.

Cool! Never heard of Areca before this - what did you pay for it? How many
drives? What kind of workload do you have? How do you measure performance?

- Luke