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Conclusion

The SSD Workload Performance Analysis
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Our testing focused on three of the most powerful flash SSDs from Intel and Samsung, and was aimed at analyzing the performance impact of heavily changing workloads. This issue is becoming more and more important, as wear leveling and performance optimization algorithms try to adjust to certain workload types, probably causing other workloads to become slower than expected. Block-level fragmentation is the main issue here, as flash SSDs store data in pieces in a way that is different from your file system, as well as the way traditional hard drives operate.

Performance Issues

Our benchmark cycle alternated traditional throughput and I/O benchmarks three times, and added three more throughput test runs to see whether or not the SSDs are capable of returning from degraded throughput levels to the sequential performance levels you actually paid for. As expected, all SSDs showed a performance decrease, but only the two products based on MLC flash exhibited significant performance drops. The impact on I/O performance is typically small and acceptable, while throughput on the two MLC flash SSDs by Intel and Samsung suffered quite a bit.

Intel’s X25-M has been the fastest consumer drive and it typically still is, but only if you update the firmware with the latest available version. While the X25-M showed severe performance reduction in sequential writes after heavy I/O, it managed to handle the changing workloads much better with the latest firmware. Samsung’s PB22-J flash SSD also showed performance drops following the change of workload, but the drops were much smaller across the board.

And Solutions

We believe that firmware updates for flash-based SSDs could become more popular, and at least as important as software updates for your motherboard. There still is room for optimization, and all serious flash SSD vendors will take advantage of it. Hence, it makes sense to install the latest firmware version, not only to avoid severe performance drops, but also to make sure your SSD performance is maximized.

The other solution is to make sure that you don’t throw lots of changing workloads at your MLC flash SSD, as this does result in a noticeable performance impact. Such workloads would be intensive P2P downloads and activities that lead to fragmentation. While fragmentation on a file level, as you may be familiar with it, isn’t an issue for flash SSDs, block level fragmentation is. In such a case, the SSD has to store data across multiple flash cells; this requires frequent read, erase, and write processes, which is what takes the most time on MLC flash SSDs. This happens inside the flash SSD and cannot be influenced by the SATA controller or the operating system. At the same time, you should also avoid running conventional defragmentation tools on a flash SSD—they only appear to tidy up file storage, while actually contributing to block level fragmentation.

Finally, we want to remind you that a flash SSD, which doesn’t have to answer to drastically changing workloads, will not show performance drops as significant as in seen in this analysis. Temporary files and similar random information won’t become an issue unless they become a serious workload for the SSD. Fast SSDs, like those used for this article, are definitely faster than any conventional hard drive.

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  • 1 Hide
    mrubermonkey , April 27, 2009 7:16 AM
    Props to you guys for this review.
  • 3 Hide
    Tindytim , April 27, 2009 7:47 AM
    I really wish we were able to Thumb up or Thumb down articles. This one would get a large thumbs up from me.
  • 1 Hide
    chookman , April 27, 2009 7:58 AM
    Thumbs up on this one too from me. Although if anyone desires more in depth understanding of the problem i found the PC Perspective articles better in that aspect.

    Intel Firmware change
    http://www.pcper.com/article.php?aid=691

    OCZ Indilinx Chip
    http://www.pcper.com/article.php?aid=670
  • -9 Hide
    chookman , April 27, 2009 7:58 AM
    Thumbs up on this one too from me. Although if anyone desires more in depth understanding of the problem i found the PC Perspective articles better in that aspect.

    Intel Firmware change
    http://www.pcper.com/article.php?aid=691

    OCZ Indilinx Chip
    http://www.pcper.com/article.php?aid=670
  • -8 Hide
    chookman , April 27, 2009 7:59 AM
    Thumbs up on this one too from me. Although if anyone desires more in depth understanding of the problem i found the PC Perspective articles better in that aspect.

    Intel Firmware change
    http://www.pcper.com/article.php?aid=691

    OCZ Indilinx Chip
    http://www.pcper.com/article.php?aid=670
  • 5 Hide
    empstar , April 27, 2009 8:55 AM
    why don't show the HDD read / write data here together with SDD?
  • -4 Hide
    lire210 , April 27, 2009 10:56 AM
    this will not matter at all to servers until the price gooes down. the speed does not make sence in the 4+ bucks a gig. normal hd are safer just in the fact that you can put 7 hd and put it in a raid one fails o well. plus 800 bucks for 64gb o my god
  • 4 Hide
    snotling , April 27, 2009 11:29 AM
    lire210this will not matter at all to servers until the price gooes down. the speed does not make sence in the 4+ bucks a gig. normal hd are safer just in the fact that you can put 7 hd and put it in a raid one fails o well. plus 800 bucks for 64gb o my god

    Servers are actually where these drives makes the most sense, and you can RAID SSDs just like you RAID HDs... and about being "safe" well I would put my money on the technology with no moving parts!
  • 6 Hide
    xsamitt , April 27, 2009 12:27 PM
    I keep waiting for a reviews of new monitors.it seems we keep getting almost the same kind of topic every week lately.
  • 0 Hide
    rubix_1011 , April 27, 2009 1:37 PM
    I have to agree with most people on this one...a flashback to the really good reviews Tom's did in the past. A very relevant review for most people with some good data and testing steps.
  • 0 Hide
    arkadi , April 27, 2009 1:39 PM
    Well it like it was written specially for me. Grate job! One of the best articles i encounter in long time.
    I posted a question on storage configuration just few day ago, with no reply btw, with exactly the same thing on my mind. Hope we can go deeper with that, and talk how we can take an advantage of what we learned here in different situations with diffident storage/system configuration's, combining SSD with regular drives, raid configurations, moving tmp/swap some programs etc.. to different drives etc...
  • -4 Hide
    arkadi , April 27, 2009 1:40 PM
    Well it like it was written specially for me. Grate job! One of the best articles i encounter in long time.
    I posted a question on storage configuration just few day ago, with no reply btw, with exactly the same thing on my mind. Hope we can go deeper with that, and talk how we can take an advantage of what we learned here in different situations with diffident storage/system configuration's, combining SSD with regular drives, raid configurations, moving tmp/swap some programs etc.. to different drives etc...
  • 1 Hide
    tipoo , April 27, 2009 1:45 PM
    Nice review. So will you guys be reviewing the 1TB PCI-Express OCZ SSD? :-)
  • 0 Hide
    Anonymous , April 27, 2009 2:50 PM
    So if your SSD starts to slow down, does a reformat get rid of that issue?
  • 0 Hide
    yourhighness , April 27, 2009 4:22 PM
    You guys had any problems with that Power Supply?

    I bought an OCZ Elite Extreme 800W PSU last year an dhad 3 of them die in 6 months....The RMA process was long and slow, but they eventually made it right by upgrading me to a PC Power and cooling PSU.
  • 2 Hide
    Area51 , April 27, 2009 4:49 PM
    lire210this will not matter at all to servers until the price gooes down. the speed does not make sence in the 4+ bucks a gig. normal hd are safer just in the fact that you can put 7 hd and put it in a raid one fails o well. plus 800 bucks for 64gb o my god

    You need to have a better understanding of the problem before you make statements like this...

    1. The number of HD required to get the same IOPS will put the total price to be higher than SSD's
    2. The power requirement is much higher for the number of HD that you need to get the same performance as a single Intel SLC SSD. This can drop the power consumption of a server significantly down from regular HD, and increase it’s performance.
    3. Remember that in many servers it’s not the capacity that matters, It’s the performance that is more important.
    4. Since SSD's can do a very nice job of simultaneous read, and write running multiple jobs is not derogated by the SSD's as it is with regular HD's.
    5. SMART command in SSD’s can give you a predictive failure analysis, something that you cannot do with HD’s, HD’s can only show you if the Drive is good or bad. This is very important since data can be copied before the drive goes bad.
    6. MTBF of SSD’s (at lease Intel’s) are much higher than HD’s. 2M hrs. vs 1.2M hrs on HD’s


  • 2 Hide
    krazyderek , April 27, 2009 11:06 PM
    wheres the OCZ vertex ?????
  • 0 Hide
    krazyderek , April 27, 2009 11:08 PM
    lire210this will not matter at all to servers until the price gooes down. the speed does not make sence in the 4+ bucks a gig. normal hd are safer just in the fact that you can put 7 hd and put it in a raid one fails o well. plus 800 bucks for 64gb o my god

    have you seen how much SAS drives are??
  • 0 Hide
    hustler539 , April 28, 2009 11:07 AM
    Good to see more review sites doing articles on these performance degradations, helps us make a better informed decision when purchasing new hardware.

    Here's another great article which gives you a good in depth look at it
    http://www.anandtech.com/storage/showdoc.aspx?i=3531&p=4
    a must read if you are thinking of upgrading to some of those new shiny ssds
  • -1 Hide
    hustler539 , April 28, 2009 11:08 AM
    krazyderekwheres the OCZ vertex ?????



    ^ a review of that is in the article as well
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