We return now to that classic block storage benchmark, Storage Performance Council (SPC) results*. There have been only two new SPC submissions since our last report, namely the Oracle Sun Storage 6780 and HP StorageWorks 6400 EVA (with SSD) for SPC-1 and SPC-1/E respectively. You may recall that SPC-1/E is an energy monitored version of the SPC-1 test so we have been combing the two test results into one series
The chart that has changed most since our last report is LRT results.
The new HP 6400 EVA with SSDs showed up at #8 on this chart. Not as good as the TMS SSD runs but not bad for a mid-range subsystem. The EVA supported RAID 5 and had 8-73GB SSDs which put it on the small side. Nonetheless, the EVA SSD subsystem was priced around ~$121K US, which puts it at ~$350/GB pricy for storage today but this is SSD.
This chart also changed with the addition of the Oracle Sun 6780 with 146GB/15Krpm FC drives but I would defy anyone from showing us what has changed. For the discerning among you, the Oracle subsystem shows up at around 62K IOPS with an LRT of ~1.8msec and costing ~$43K US.
The SPC-1/E benchmark submissions report on IOPs/Watt measurements taken at Nominal, Medium and High daily workloads. As one can see the HP EVA with SSDs did fairly well at the Medium and High workloads but as it’s SSD based storage we would expect it to. But the Nominal workload IOPs/W for the SSD subsystem is worthy of discussion.
SPC defines moderate and heavy workloads at 50 and 80% of maximum reported performance respectively and then defines
- Nominal daily workload as 16 hours of idle time and 8 hours of moderate workload,
- Medium daily workload as 6 hours of idle time, 14 hours of moderate workload and 4 hours of heavy workload, and
- High daily workload as 0 hours of idle time, 6 hours of moderate workload, and 18 hours of heavy workload.
As one can see the subsystem will determine the levels of IOPs used to determine nominal, medium, and heavy. Curent results show two things about the HP EVA SSDs
- The idle power consumption of HP EVA SSDs is pretty high compared to the Xiotech’s systems.
- The relative lack of power difference between nominal (465.0w) and high (471.9w) workloads for SSDs punishes them in the nominal usage scenario.
For the three current SPC-1/E benchmarks (Xiotech Emprise 5000 with 146GB drives, Xiotech Emprise 5000 with 600GB drives and the new HP StorageWorks EVA with SSDs) we show a new bubble chart depicting power and IOPS for medium and high workloads. The smallest bubble pair shown above is the Xiotech with 146GB, the middle size bubble pair is the Xiotech with 600GB and the largest bubble pair is the HP EVA with SSDs.
So why don’t we see a significant increase in power consumption with the SSDs. We have discussed this before but SSD power consumption doesn’t increase much as you drive it harder. So the 50% IOPS rate consumed ~469 watts and the 80% IOPS rate consumed about ~473 watts. Unclear why the SSD subsystem actually consumed more power than the other two disk drive subsystems but realize the EVA was a fully configured storage subsystem with FC attached SSDs and 8GB of cache (not to say the Emprise subsystems were not).
The other charts for SPC-1 and SPC-2 were unchanged and have all been covered in prior reports. SPC benchmark submissions have been slowing down of late. Unsure but this might be indicative of new products coming out, delaying submissions.
SSD storage energy profiles are certainly different than hard drives. I would have thought that any SSD subsystem would consume less power than a comparable hard drive subsystem. But that certainly wasn’t the case for the Xiotech vs. HP EVA. Nonetheless, the EVA SSD subsystem did put up some interesting response times and on a iops/Watt basis it did very well in the medium and high daily workloads.
We can only hope for more SPC-1/E test submissions. It’s exactly the same as the SPC-1 testing except for the power monitoring and it would supply power consumption metrics as well as performance with the same submission. Makes sense to me, but I don’t have to pay for the monitoring equipment.
As always if you have any suggestions on how we can improve our SPC or any performance analysis, please don’t hesitate to drop us a line. Our contact information can be found in the footer of this page.
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A PDF version of this can be found atSCI 2010 Aug 27 Latest Storage Performance Council (SPC) results analyzed
Silverton Consulting, Inc. is a Storage, Strategy & Systems consulting services company, based in the USA offering products and services to the data storage community.