Latest SPC-1 results – IOPS vs drive counts – chart-of-the-month

Scatter plot of SPC-1  IOPS against Spindle count, with linear regression line showing Y=186.18X + 10227 with R**2=0.96064
(SCISPC111122-004) (c) 2011 Silverton Consulting, All Rights Reserved

[As promised, I am trying to get up-to-date on my performance charts from our monthly newsletters. This one brings us current up through November.]

The above chart plots Storage Performance Council SPC-1 IOPS against spindle count.  On this chart, we have eliminated any SSD systems, systems with drives smaller than 140 GB and any systems with multiple drive sizes.

Alas, the regression coefficient (R**2) of 0.96 tells us that SPC-1 IOPS performance is mainly driven by drive count.  But what’s more interesting here is that as drive counts get higher than say 1000, the variance surrounding the linear regression line widens – implying that system sophistication starts to matter more.

Processing power matters

For instance, if you look at the three systems centered around 2000 drives, they are (from lowest to highest IOPS) 4-node IBM SVC 5.1, 6-node IBM SVC 5.1 and an 8-node HP 3PAR V800 storage system.  This tells us that the more processing (nodes) you throw at an IOPS workload given similar spindle counts, the more efficient it can be.

System sophistication can matter too

The other interesting facet on this chart comes from examining the three systems centered around 250K IOPS that span from ~1150 to ~1500 drives.

  • The 1156 drive system is the latest HDS VSP 8-VSD (virtual storage directors, or processing nodes) running with dynamically (thinly) provisioned volumes – which is the first and only SPC-1 submission using thin provisioning.
  • The 1280 drive system is a (now HP) 3PAR T800 8-node system.
  • The 1536 drive system is an IBM SVC 4.3 8-node storage system.

One would think that thin provisioning would degrade storage performance and maybe it did but without a non-dynamically provisioned HDS VSP benchmark to compare against, it’s hard to tell.  However, the fact that the HDS-VSP performed as well as the other systems did with much lower drive counts seems to tell us that thin provisioning potentially uses hard drives more efficiently than fat provisioning, the 8-VSD HDS VSP is more effective than an 8-node IBM SVC 4.3 and an 8-node (HP) 3PAR T800 systems, or perhaps some combination of these.


The full SPC performance report went out to our newsletter subscriber’s last November.  [The one change to this chart from the full report is the date in the chart’s title was wrong and is fixed here].  A copy of the full report will be up on the dispatches page of our website sometime this month (if all goes well). However, you can get performance information now and subscribe to future newsletters to receive these reports even earlier by just sending us an email or using the signup form above right.

For a more extensive discussion of block or SAN storage performance covering SPC-1&-2 (top 30) and ESRP (top 20) results please consider purchasing our recently updated SAN Storage Buying Guide available on our website.

As always, we welcome any suggestions on how to improve our analysis of SPC results or any of our other storage system performance discussions.