Sequential Read/Write Speed

Finally, to the roundup. We’ll start with the traditional tests. Using the latest build of Iometer I ran a 3 minute long 2MB sequential write test over the entire span of the drive. The results reported are in average MB/s over the entire test length:

Sequential write speed was what all SSD makers focused on in the early days of consumer drives. The JMicron lesson taught us that there's much more to system performance than sequential write performance, and most have learned. Regardless, sequential write speed is still very important and as we can see here the majority of drives do very, very well. The high end Indilinx drives approach 190MB/s, while Intel's SLC X25-E actually breaks 200MB/s.

The same can't be said for Intel's mainstream MLC drives, both of which are limited to 80MB/s. While it doesn't make the drives feel slow in real world usage, it is a significant blemish on an otherwise (as you'll soon see) flawless track record.

The standings don't really change with the drive in a used state. The Indilinx drives all fall around 15%, while the Intel drives stay the same.

Ha! Read speed is ridiculous on these drives. See the wall at around 260MB/s? We're hitting the limit of what's possible over 3Gbps SATA. Expect read speeds to go up once we start seeing SATA 6Gbps drives and controllers to support them.

Why You Absolutely Need an SSD Random Read/Write Speed
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  • Anand Lal Shimpi - Monday, August 31, 2009 - link

    Maybe I should compile these things into a book? :)

    Here are my answers about some stuff:

    1) There's a spec for how hard drive makers report capacity. They define 1GB as 1 billion bytes. This is technically correct (base 10 SI prefix as you correctly pointed out). The HDDs also physically have this much storage on them, they are made up of sequentially numbered sectors that are easily counted in a decimal number system.

    All other aspects of PC storage (e.g. cache, DRAM, NAND flash) however work in base 2 (like the rest of the PC). In these respects 1GB is defined as 1024^3 because we're dealing with a base 2 number system. There are reasons for this but it goes beyond the scope of what I'm posting :)

    Intel adheres to the same spec that the HDD makers use. But the X25-M is made up of flash, which as I just mentioned is addressed in a base 2 number system. There's more flash than user space on the drive, it's used as spare area, woohoo. I think we're both on the same page here, just saying things differently :)

    2) We'll see a 320GB drive, just not this year. I don't know that the demand is there especially given the weak economy.

    Dreams do sometimes come true... ;)

    3) Perhaps, but I don't like the idea of a drive doing anything but idling when it's supposed to be...idle. This does funny things to notebook battery life I'd think.

    4) This is true. There's also another thing you can do with the jumper (and perhaps some additional software): flash any indilinx drive with any firmware regardless of vendor :)

    5) I had to throw out a lot of data because of variations between runs. It ended up being a combination of immature drivers, immature benchmarks and some OS trickery. The setup I have now is very reliable and provides very repeatable results with very little variation. While I run everything three times, the runs are so close that you could technically do only one run per drive and still be fine.

    6) I wouldn't count WD and Seagate out just yet. It may take them a while but they won't go quietly...

    7) Samsung makes a ton of money from SSD sales to OEMs, they don't seem to care about the end user market as much. If end users start protesting Samsung drives however, things will change.

    In my opinion? Once Apple falls, the rest will follow. If Apple will migrate to Intel (possible) or Indilinx (less likely), we'll see the same from the other OEMs and Samsung will be forced to change.

    Or I could be too pessimistic and we'll see better performance from Samsung before then.

    8) Agreed :)

    I'll finish here too :)

    Take care,
    Anand
  • Reven - Monday, August 31, 2009 - link

    Anand, dont listen to the guys like blyndy who diss on the anthologies, I love them. You can find a basic review anywhere, its the in-depth yet simple to understand stuff like these anthologies that make me visit Anandtech all the time.

    Keep it up, dude!
  • Anand Lal Shimpi - Monday, August 31, 2009 - link

    Thank you :)
  • EasterEEL - Monday, August 31, 2009 - link

    I have a couple of questions regarding the Intel® SATA SSD Firmware Update Tool (2832KB) v1.3 8/24/2009.

    Does this firmware enable TRIM within the SSD to work with Windows 7?

    If AHCI is enabled in the BIOS (but not RAID) does Windows 7 use it's own drivers with TRIM? Or does it load Intel’s Matrix Storage Manager driver which does not support TRIM as per the article note below?

    "Unfortunately if you’re running an Intel controller in RAID mode (whether non-member RAID or not), Windows 7 loads Intel’s Matrix Storage Manager driver, which presently does not pass the TRIM command. Intel is working on a solution to this and I'd expect that it'll get fixed after the release of Intel's 34nm TRIM firmware in Q4 of this year."

  • Anand Lal Shimpi - Monday, August 31, 2009 - link

    That update does not enable TRIM. The TRIM firmware is in testing now and it will be out sometime in Q4 of this year (October - December).

    If AHCI is enabled in the BIOS and you haven't loaded Intel's MSM drivers then it will use the Windows 7 driver and TRIM will be supported.

    Take care,
    Anand
  • uberowo - Monday, August 31, 2009 - link

    I do have a question however. :D

    I am building a gaming pc, and I am buying ssd disk/s. Would I benefit from getting 2x80gb intel gen2s and using raid0? Or should I stick with a single 160gb?
  • Anand Lal Shimpi - Monday, August 31, 2009 - link

    While I haven't tested 2 x 80GB drives in RAID-0, my feeling is that a single SSD is going to be better than two in RAID going forward. As of now I don't know that anyone's TRIM firmware is going to work if you've got two drives in RAID-0.

    The perceived performance gains in RAID-0 also aren't that great on SSDs from what I've seen.

    Take care,
    Anand
  • Ardax - Monday, August 31, 2009 - link

    A naive guess would be that it depends on the workload. For lots of sequential transfers a RAID-0 should shine -- particularly on reads -- because you're spreading the transfers out over multiple SATA channels.

    Losing TRIM is a problem. Finding a controller than can handle the performance is entirely likely to be another.
  • uberowo - Monday, August 31, 2009 - link

    Thanks a lot for taking the time to answer. Not to mention making this awesome site. :)
  • Anand Lal Shimpi - Monday, August 31, 2009 - link

    You guys take the time to read it and make some truly wonderful comments, it's the least I can do :)

    -A

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