Tying it All Together: SSD Performance Degradation

More spare area is better for random workloads, but desktop workloads aren’t random enough to justify setting aside more spare area to improve performance; most reviews don’t test in a used state, and more users would simply flock to lower price-per-GB drives with less spare area.

Drives that drop the most in performance from new to used state have the most to gain from the TRIM instruction. Depending on how you use your drive of course:

  % Performance Drop in Used State vs. New State
  4KB Random Write 2MB Sequential Write PCMark Vantage HDD Suite
Intel X25-E 64GB (SLC) 26.1% 5.4% 9.7%
Intel X25-M G1 160GB (MLC) 35.5% 3.8% 16.7%
Intel X25-M G2 160GB (MLC) 0.7% 2.2% 15.3%
OCZ Agility 128GB (Indilinx MLC) 44.8% 15.0% 4.4%
OCZ Summit 256GB (Samsung MLC) 72.4% 3.0% 23.6%
OCZ Vertex EX 128GB (Indilinx SLC) 60.5% 20.8% 0.8%
OCZ Vertex Turbo 128GB (Indilinx MLC) 44.0% 15.4% 4.5%
Patriot Torqx 128GB (Indilinx MLC) 44.6% 15.6% 3.5%


Depending on the scenario, all three controllers have a lot to gain from TRIM. Random write performance drops significantly for almost every single drive. The worst is the Samsung RBB controller, which lost over 70% of its performance between new and used states; Samsung needs TRIM.

Intel made some significant improvements going from the G1 to G2 drives, the new drive loses no performance in our random write test. This is thanks to firmware tweaks and having twice as much DRAM to track data in; the more data the Intel drive can keep track of, the better it is at organization, management and garbage collection. From a pure performance standpoint, the G2 might actually be better for server workloads than the X25-E. In terms of lifespan however, the X25-E has the G2 beat.

Only the Indilinx drives lose an appreciable amount of performance in the sequential write test, but they are the only drives to not lose any performance in the more real-world PCMark Vantage HDD suite. Although not displayed here, the overall PCMark Vantage score takes an even smaller hit on Indilinx drives. This could mean that in the real world, Indilinx drives stand to gain the least from TRIM support. This is possibly due to Indilinx using a largely static LBA mapping scheme; the only spare area is then the 6.25% outside of user space regardless of how used the drive is.

Both Samsung and Intel have a lot to gain from TRIM. Samsung’s performances goes from utterly unacceptable to reasonable (but not price justified) with TRIM. Intel’s performance goes from class-leading to more, er, class-leading.

The Instruction That Changes (almost) Everything: TRIM Used vs. New Performance: Revisited


View All Comments

  • nemitech - Monday, August 31, 2009 - link

    opps - not ebay - it was NEWEGG. Reply
  • Loki726 - Monday, August 31, 2009 - link

    Thanks a ton for including the pidgin compiler benchmarks. I didn't think that HD performance would make much of a difference (linking large builds might be a different story), but it is great to have numbers to back up that intuition. Keep it up. Reply
  • torsteinowich - Monday, August 31, 2009 - link


    You write that the Indilinx wiper tool collects a free page list from the OS, then wipes the pages. This sounds like a dangerous operation to me since the OS might allocate some of these blocks after the tool collects the list, but before they are wiped.

    Have you received a good explanation for Indilinx about how they ensure file system integrity? As far as i know Windows cannot temporarily switch to read-only mode on an active file system (at least not the system drive). The only way i could see this tool working safely would be by booting off a different media and accessing the file system to be trimmed offline with a tool that correctly identifies the unused pages for the particular file system being used. I could be wrong of course, maybe windows 7 has a system call to temporarily freeze FS writes, but i doubt it.
  • has407 - Monday, August 31, 2009 - link

    It: (1) creates a large temporary file (wiper.dat) which gobbles up all (or most) of the free space; (2) determines the LBA's occupied by that file; (3) tells the SSD to TRIM those LBA's; and then (4) deletes the temporary file (wiper.date).

    From the OS/filesystem perspective, it's just another app and another file. (A similar technique is used by, e.g., sysinternals Windows SDelete app to zero free space. For Windows you could also probably use the hooks used by defrag utilities to accomplis it, but that would be a lot more work.)
  • cghebert - Monday, August 31, 2009 - link


    Great article. Once again you have outclassed pretty much every other site out there with the depth of content in this review. You should start marketing t-shirts that say "Everything I learned about SSDs I learned from AnandTech"

    I did have a question about gaming benchmarks, since you made this statement:

    " but as you'll see later on in my gaming tests the benefits of an SSD really vary depending on the game"

    But I never saw any gaming benchmarks. Did I miss something?
  • nafhan - Monday, August 31, 2009 - link

    Just wanted to say awesome review.
    I've been reading Anandtech since 2000, and while other sites have gone downhill or (apparently) succumbed to pressure from advertisers, you guys have continued to give in depth, critical reviews.
    I also appreciate that you do some real analysis instead of just throwing 10 pages of charts online.
    Thanks, and keep up the good work!
  • zysurge - Monday, August 31, 2009 - link

    Awesome amazing article. So much information, presented clearly.

    Question, though? I have an Intel G2 160GB drive coming in the next few days for my Dell D830 laptop, which will be running Windows 7 x64.

    Do I set the controller to ATA and use the Intel Matrix driver, or set it to AHCI and use Microsoft's driver? Will either provide an advantage? I realize neither will provide TRIM until Q4, but after the firmware update, both should, right?

    Thanks in advance!
  • ggathagan - Wednesday, September 16, 2009 - link

    From page 15 (Early Trim support...):
    Under Windows 7 that means you have to use a Microsoft made IDE or AHCI driver (you can't install chipset drivers from anyone else).
  • Mumrik - Monday, August 31, 2009 - link

    but I can't live with less than 300GB on that drive, and SSDs in usable sizes still cost more than high end video cards :-(

    I really hope I'll be able to pick up a 300GB drive for 100-200 bucks in a year or so, but it is probably a bit too optimistic.
  • Simen1 - Monday, August 31, 2009 - link

    This is simply wrong. Ask anyone over 10 years if they think this mathematical statement is true or false. 80 can never equal 74,5.

    Now, someone claims that 1 GB = 10^9 B and others claim that 1 GB is 2^30 B. Who is really right? What does the G and the B mean? Who defines that?

    The answers is easy to find and document. B means Byte. G stands for Giga ans means 10^6, not 2^30. Giga is defined in the international system of units, SI.

    No standardization organization have _ever_ defined Giga to be 2^30. But IEC, International Electrotechnical Commission, have defined "Gi" to 2^30. This is supposed to be used for digital storage so people wont be confused by all the misunderstandings around this. Misunderstandings that mainly comes from Microsoft and quite a few other big software vendors. Companies that ignore the mathematical errors in their software when they claim that 80GB = 74,5 GB, and ignore both international standards on how to shorten large numbers.

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