SAS12 10k HDD vs SATA-III SSD

I have a server in production that is currently running some 2.4TB SAS12 10K HDD the show the following performance

  • Spindle Speed (rpm): 10,000 Rpm
  • Average Latency (ms): 2.9 Ms
  • Sustained Transfer Rate (outer To Inner Diameter, Mb/s): 270 To 117
  • Cache Multisegmented (mb): 256 Mb
  • External Transfer Rate: 1200 Mbps

I’m looking at upgrading to flash storage as I’ve had two drives fail in the last 3 months. figure flash has a lower failure rate since there are no moving parts. Another reason im looking at change is the 10K drive always seem to run HOT TNS usually shows these running around 40C.

I’m looking at some Sata drive that have the following performance

  • Seq. Read (128 Kb) : 520 Mb/s
  • Seq. Write (128 Kb) : 480 Mb/s
  • Rand. Read (4kb, Qd32) : 97k Iops
  • Rand. Write (4kb, Qd32) : 24k Iops

As far as I can tell even though the SATA SSD have a slower interface(6GB/s vs 12GB/s) they are still about twice a fast. I just wanted a sanity check that I am reading that correctly

Yes you are. There’s no way a spinning drive can make full use of even SATA 2 (3 gb/s). SATA 3, SAS 6 Gb/s and 12 Gb/s were introduced for SSDs (or, in the case of SAS, expanders putting the throughput of multiple drives in a single lane).

ok follow up question. I was also looking at some SAS SSD. I found these Toshiba CM5-R KCM5DRUG3T84
serversupply list them as SAS12 for the host interface but then show the interface as PCEI. When I look the cut sheet from toshiba I don’t see any mention of sas does that mean they are really U.2 and wont work with dell HBA330 sas controller?

another option I was looking at some Toshiba PM5-R KPM5XRUG3T84
they definitely seem to be SAS12.

Because of my homelab experience I’ve become the defacto IT guy at the small business I work for. I have less experience with the enterprise grade SSD/HDD but and wanting and trying to learn more as I really enjoy it both at home and work.

Correct: CR# are NVMe, PM# are SAS.

1 Like