On Sat, Nov 27, 2010 at 9:34 AM, Christopher George <cgeo...@ddrdrive.com>wrote:
> > I haven't had a chance to test a Vertex 2 PRO against my 2 EX, and I'd > > be interested if anyone else has. > > I recently presented at the OpenStorage Summit 2010 and compared > exactly the three devices you mention in your post (Vertex 2 EX, > Vertex 2 Pro, and the DDRdrive X1) as ZIL Accelerators. > > Jump to slide 37 for the write IOPS benchmarks: > > http://www.ddrdrive.com/zil_accelerator.pdf > > > and you *really* want to make sure you get the 4k alignment right > > Excellent point, starting on slide 66 the performance impact of partition > misalignment is illustrated. Considering the results, longevity might be > an even greater concern than decreased IOPS performance as ZIL > acceleration is a worst case scenario for a Flash based SSD. > > > The DDRdrive is still the way to go for the ultimate ZIL accelleration, > > but it's pricey as hell. > > In addition to product cost, I believe IOPS/$ is a relevant point of > comparison. > > Google products gives the price range for the OCZ 50GB SSDs: > Vertex 2 EX (OCZSSD2-2VTXEX50G: $870 - $1,011 USD) > Vertex 2 Pro (OCZSSD2-2VTXP50G: $399 - $525 USD) > > 4KB Sustained and Aligned Mixed Write IOPS results (See pdf above): > Vertex 2 EX (6325 IOPS) > Vertex 2 Pro (3252 IOPS) > DDRdrive X1 (38701 IOPS) > > Using the lowest online price for both the Vertex 2 EX and Vertex 2 Pro, > and the full list price (SRP) of the DDRdrive X1. > > IOPS/Dollar($): > Vertex 2 EX (6325 IOPS / $870) = 7.27 > Vertex 2 Pro (3252 IOPS / $399) = 8.15 > DDRdrive X1 (38701 IOPS / $1,995) = 19.40 > > Best regards, > Why would you disable TRIM on an SSD benchmark? I can't imagine anyone intentionally crippling their drive in the real-world. Furthermore, I don't think "1 hour sustained" is a very accurate benchmark. Most workloads are bursty in nature. If you're doing sustained high-IOPS workloads like that, the back-end is going to fall over and die long before the hour time-limit. Your 38k IOPS would need nearly 500 drives to sustain that workload with any kind of decent latency. If you've got 500 drives, you're going to want a hell of a lot more ZIL space than the ddrdrive currently provides. I'm all for benchmarks, but try doing something a bit more realistic. --Tim
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