One Tough Act to Follow

What have I gotten myself into? The SSD Anthology I wrote back in March was read over 2 million times. Microsoft linked it, Wikipedia linked it, my esteemed colleagues in the press linked it, Linus freakin Torvalds linked it.

The Anthology took me six months to piece together; I wrote and re-wrote parts of that article more times than I'd care to admit. And today I'm charged with the task of producing its successor. I can't do it.

The article that started all of this was the Intel X25-M review. Intel gave me gold with that drive; the article wrote itself, the X25-M was awesome, everything else in the market was crap.


Intel's X25-M SSDs: The drives that started a revolution

The Anthology all began with a spark: the SSD performance degradation issue. It took a while to put together, but the concept and the article were handed to me on a silver platter: just use an SSD for a while and you’ll spot the issue. I just had to do the testing and writing.


OCZ's Vertex: The first Indilinx drive I reviewed, the drive that gave us hope there might be another.

But today, as I write this, the words just aren't coming to me. The material is all there, but it just seems so mature and at the same time, so clouded and so done. We've found the undiscovered country, we've left no stone unturned, everyone knows how these things work - now SSD reviews join the rest as a bunch of graphs and analysis, hopefully with witty commentary in between.

It's a daunting, no, deflating task to write what I view as the third part in this trilogy of articles. JMicron is all but gone from the market for now, Indilinx came and improved (a lot) and TRIM is nearly upon us. Plus, we all know how trilogies turn out. Here's hoping that this one doesn't have Ewoks in it.

What Goes Around, Comes Around

No we're not going back to the stuttering crap that shipped for months before Intel released their X25-M last year, but we are going back in the way we have to look at SSD performance.

In my X25-M review the focus was on why the mainstream drives at the time stuttered and why the X25-M didn't. Performance degradation over time didn't matter because all of the SSDs on the market were slow out of the box; and as I later showed, the pre-Intel MLC SSDs didn’t perform worse over time, they sucked all of the time.

Samsung and Indilinx emerged with high performance, non-stuttering alternatives, and then we once again had to thin the herd. Simply not stuttering wasn't enough, a good SSD had to maintain a reasonable amount of performance over the life of the drive.

The falling performance was actually a side effect of the way NAND flash works. You write in pages (4KB) but you can only erase in blocks (128 pages or 512KB); thus SSDs don't erase data when you delete it, only when they run out of space to write internally. When that time comes, you run into a nasty situation called the read-modify-write. Here, even to just write 4KB, the controller must read an entire block (512KB), update the single page, and write the entire block back out. Instead of writing 4KB, the controller has to actually write 512KB - a much slower operation.

I simulated this worst case scenario performance by writing to every single page on the SSDs I tested before running any tests. The performance degradation ranged from negligible to significant:

PCMark Vantage HDD Score New "Used"
Corsair P256 (Samsung MLC) 26607 18786
OCZ Vertex Turbo (Indilinx MLC) 26157 25035

 

So that's how I approached today's article. Filling the latest generations of Indilinx, Intel and Samsung drives before testing them. But, my friends, things have changed.

The table below shows the performance of the same drives showcased above, but after running the TRIM instruction (or a close equivalent) against their contents:

PCMark Vantage HDD Score New "Used" After TRIM/Idle GC % of New Perf
Corsair P256 (Samsung MLC) 26607 18786 24317 91%
OCZ Vertex Turbo (Indilinx MLC) 26157 25035 26038 99.5%

 

Oh boy. I need a new way to test.

A Quick Flash Refresher
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  • Bonesdad - Sunday, October 10, 2010 - link

    Been over a year since this article was published...still very relevant. Any plans to update it with the latest products/drivers/firmware? There have been some significant updates, and it would be good to at least have updated comparisons.

    Well done, more more more!
  • hescominsoon - Thursday, February 17, 2011 - link

    Excellent article but you left out sandforce. I'm curious if this was an oversight or a purposeful moission.
  • PHT - Friday, September 28, 2012 - link

    This article is fantastic, the best I ever read about SSD.
    Any follow up with new SATA III drives and new controllers like SandForce, new Indilinx etc.?
    I will be glad to see it.

    My Best
    Zygmunt
  • lucasgonz - Wednesday, October 16, 2013 - link

    Hello everyone.
    This post is quite old but I hope someone can answer.
    I am concerned about the life of my ssd (sandisk extreme 240). I performed partitions ignoring the issue of the level of wear and partitions. I have it for one year ago with a 30gb partition and one with 200GB. I wanted to use large drive for data but I did not have time for that and just use the first 30gb partition . My question is if the ssd may be damaged by using only a little segment. DiskInfo shows 10tb reading 18 tb and writing.
    sorry my poor English.
    Thanks for any help.
  • Ojaswin Singh - Monday, January 13, 2014 - link

    Hey,This is the most informative article i have ever read.Can You Please clear Out Some Of my Doubts:-
    1.Does Playing Video Games or Running Programs add to Writing on the SSD
    2.Is 1 Write Cycle=Filling 120GB of SSD once
    3.I really write on my HDD a lot(Seriusly a Lot) So how much life cycle can i expect from Samsung 840 SSD(Neither Pro nor EVO) I mean for how much time can i expect it to be writable
    Please Help me cause i want the speeds of SSD but i want it to last for me too
    Thanks,
    Ojaswin

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