SSD Aging: Read Speed is Largely Unaffected

Given the nature of the SSD performance-over-time “problem” you’d expect to only pay the performance penalty when writing files, not reading. And for once, I don’t have any weird exceptions to talk about - this is generally the case.

The table below shows sequential read performance for 2MB blocks on new vs. “used” SSDs. I even included data for a couple of the hard drives in the "Used" column; for those numbers I'm simply measuring transfer rates from the slowest parts of the platter:

2MB Sequential Read Speed New "Used"
Intel X25-E   240.1 MB/s
Intel X25-M 264.1 MB/s 230.2 MB/s
JMicron JMF602B MLC 134.7 MB/s 134.7 MB/s
JMicron JMF602Bx2 MLC 164.1 MB/s 164.1 MB/s
OCZ Summit 248.6 MB/s 208.6 MB/s
OCZ Vertex 257.8 MB/s 250.1 MB/s
Samsung SLC   101.4 MB/s
Seagate Momentus 5400.6 77.9 MB/s -
Western Digital Caviar SE16 104.6 MB/s 54.3 MB/s
Western Digital VelociRaptor 118.0 MB/s 79.2 MB/s

 

The best SSDs still transfer data at over 2x the rate of the VelociRaptor.

Read latency is also extremely good on these worn SSDs:

I left the conventional hard drives out of the chart simply because they completely screw up the scale. The VelociRaptor has a latency of 7.2ms in this iometer test with a queue depth of 3 IOs; that's an order of magnitude slower than the slowest SSD here.

Since you only pay the overhead penalty when you go to write to a previously-written block, the performance degradation only really occurs when you’re writing - not when you’re reading.

Now your OS is always writing to your drive, and that’s why we see a performance impact even if you’re just launching applications and opening files and such, but the penalty is much less tangible when it comes to read performance.

New vs Used SSD Performance The Verdict
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  • jay401 - Wednesday, March 18, 2009 - link

    yeah, he wants "more expensive than" or "too expensive for". Reply
  • Spoelie - Wednesday, March 18, 2009 - link

    Second page as well:

    missing charts before and after this paragraph:

    "The chart above shows how much faster these affordable MLC SSDs were than the fastest 3.5” hard drive in sequential transfers. But now look at random write performance:"
    Reply
  • Spoelie - Wednesday, March 18, 2009 - link

    chart 1 on page 2 now shows sequential read but the paragraph is changed to mention random read ;)

    page 21: As far as I know, this is THE one of THE only reviews

    Some very surprising benchmark results for the ocz vertex, I thought the new firmware tanked sequential read speeds (to 80-90) based on the explanation beforehand, but not according to the actual graphs.
    Reply
  • Spoelie - Wednesday, March 18, 2009 - link

    third page, first table, first column: SSD and HDD entries are switched Reply
  • mikaela - Tuesday, March 16, 2010 - link

    yeah great info. also great resource Reply
  • Spoelie - Wednesday, March 18, 2009 - link

    page 19: I’d never reviewed it
    'd & -ed?
    Reply
  • HolyFire - Wednesday, March 18, 2009 - link

    "I'd never reviewed it" is correct. "I'd" here means "I had", it's Past Perfect tense. Reply
  • FishTankX - Wednesday, March 18, 2009 - link

    That should have bolded "too" Reply
  • FishTankX - Wednesday, March 18, 2009 - link

    Also, I think the velociraptor vs X-25 figures are swapped. 6 odd ms for the intel drive and 0.11ms for the velociraptor.. Reply
  • Natfly - Wednesday, March 18, 2009 - link

    Reply

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