SPECsfs2008 NFS SSD/NAND performance, take two – chart-of-the-month

SCISFS120623-010(002) (c) 2012 Silverton Consulting, Inc. All Rights Reserved

For some time now I have been experimenting with different approaches to normalize IO activity (in the chart above its NFS throughput operations per second) for systems that use SSDs or Flash Cache.  My previous attempt  (see prior SPECsfs2008 chart of the month post) normalized base on GB of NAND capacity used in a submission.

I found the previous chart to be somewhat lacking so this quarter I decided to use SSD device and/or Flash Cache card count instead.  This approach is shown in the above chart. Funny thing, although the rankings were exactly the same between the two charts one can see significant changes in the magnitudes achieved, especially in the relative values, between the top 2 rankings.

For example, in the prior chart Avere FXT 3500 result still came in at number one but whereas here they achieved ~390K NFS ops/sec/SSD on the prior chart they obtained ~2000 NFS ops/sec/NAND-GB. But more interesting was the number two result. Here the NetApp FAS6240 with 1TB Flash Cache Card achieved ~190K NFS ops/sec/FC-card but on the prior chart they only hit ~185 NFS ops/sec/NAND-GB.

That means on this version of the normalization the Avere is about 2X more effective than the NetApp FAS6240 with 1TB FlashCache card but in the prior chart they were 10X more effective in ops/sec/NAND-GB. I feel this is getting closer to the truth but not quite there yet.

We still have the problem that all the SPECsfs2008 submissions that use SSDs or FlashCache also have disk drives as well as (sometimes significant) DRAM cache in them.  So doing a pure SSD normalization may never suffice for these systems.

On the other hand, I have taken a shot at normalizing SPECsfs2008 performance for SSDs-NAND, disk devices and DRAM caching as one dimension in a ChampionsChart™ I use for a NAS Buying Guide, for sale on my website.  If your interested in seeing it, drop me a line, or better yet purchase the guide.

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The complete SPECsfs2008 performance report went out in SCI’s June newsletter.  But a copy of the report will be posted on our dispatches page sometime next month (if all goes well).  However, you can get the SPECsfs2008 performance analysis now and subscribe to future free newsletters by just using the signup form above right.

For a more extensive discussion of current NAS or file system storage performance covering SPECsfs2008 (Top 20) results and our new ChampionsChart™ for NFS and CIFS storage systems, please see SCI’s NAS Buying Guide available from our website.

As always, we welcome any suggestions or comments on how to improve our analysis of SPECsfs2008 results or any of our other storage performance analyses.


2 Replies to “SPECsfs2008 NFS SSD/NAND performance, take two – chart-of-the-month”

  1. Ray,
    as it turns out I've been doing some similar work for some blog posts that I've yet to write around cache effectiveness for different workload profiles and working set sizes. If you're interested I'd be happy to share the spreadhsheet I've been working on (mostly from SPC-1 as this unlike SPEC allows you to vary the working set sizes vs IOPS).. Part of the challenge is coming up with metrics that provide predictive or other value that actually correlate with reality. I cant say I'm happy with what I've come up with so far, but I'd be happy to share the draft results if you're interested.

    Regards
    John

    1. John,Thanks for your perceptive comment.I would be happy to collaborate with you on this. It's extremely hard to extract SSD, cache and drive effectiveness from the noise in storage benchmarks today but I believe it's definitely worth the effort. Not sure how I would design a different benchmark to do a better job at this but that's probably worth considering. Good luck on your research. My contact information is on my blog and website if you are interested in pursuing this further.Ray

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