If you are referencing a claim made by Mark Thompson, there is an extensive discussion of it during one of the Security Now podcasts last year:
http://www.grc.com/sn/sn-284.txt Relevant bit: LEO: ...Mark Thompson. The following article from Microsoft says otherwise. It's blogs.msdn.com. It's a May 2009 article, "Support Q&A for Solid-State Drives." "Should the pagefile be placed on SSDs? Yes. Most pagefile operations are small random reads or larger sequential writes, both of which are types of operations that SSDs handle well. In looking at telemetry data from thousands of traces and focusing on pagefile reads and writes, we find that, one, pagefile.sys reads outnumber pagefile.sys writes by about 40 to 1." Well, that's good to know. That's interesting. So in other words, there's a lot more reading going on than writing, 40 times more. "Two, pagefile.sys read sizes are typically quite small, with 67 percent less than or equal to 4KB, and 88 percent less than 16KB. Three, pagefile.sys writes are relatively large, with 62 percent greater than or equal to 128KB and 45 percent being exactly a megabyte in size." This is Windows, of course, only we're talking about. This is how Windows behaves. "In fact, given typical pagefile reference patterns and the favorable performance characteristics SSDs have on those patterns" - in other words, SSDs are faster with reads, they're really great with lots of small reads because the seek time is zero - "there are few files better than the pagefile to place on an SSD." Well, that kind of makes sense. The issue really more is this thrashing of the SSD. But if the files are megabyte most of the time, does that ameliorate that? STEVE: Well, this is a perfect example of a person answering a question from their perspective, but not a different perspective. That is, if all you were asking was about performance, then I completely agree. But my focus has never been on performance in this discussion. It's been on burning the things out, which this doesn't address at all. LEO: So all of those extra writes, regardless of the size of the writes, are not good. STEVE: Correct. LEO: Reads we don't care about on an SSD. Lots of reading we don't care about. It's the writing we care about. STEVE: Correct, because writing is a physically fatiguing process for an SSD. LEO: You can say that again. As the author of 13 books - no, I'm just kidding. Never do it again. STEVE: And Mark Thompson and I have discussed this at length. He's performed the experiment of using an SSD for a swap file and watching it burn out the SSD. I mean, in a relatively short time it just killed it. And so, anyway, so my advice stands, which is, if you're using an SSD, hopefully before you have gone to the expense of using an SSD, which is still much more expensive than a hard drive, you will have invested money in as much RAM as your system can handle because RAM is much less expensive, and you'll get much more, you'll get huge benefit from going to the most RAM you can possible get. And if you've done that, then turn off pagefiles. And if the only drive you have is an SSD, I stand by my advice. I agree that, from a performance standpoint, the SSD is a perfect device for containing the pagefile. Unfortunately, Microsoft thrashes their pagefile. I mean, they're writing to it a lot. Yes, 40 times less than they're reading, but it's something that's going on all the time, pretty much. I mean, we've all seen, we've watched the hard drive light flickering there, like when nothing is going on. It's like, what is it doing? Well, who knows. But we know that it's writing to the pagefile, which it does a lot. So anyway, I think it's a perfect example of two different people with very different aspects of the problem that they're addressing. I'm looking at long-term life. Microsoft's looking at performance. --------- Brian On Thu, Mar 1, 2012 at 7:57 PM, Winterlight <[email protected]>wrote: > At 03:00 PM 3/1/2012, you wrote: > >> However, do NOT put a swap file on an SSD. And don't defrag them either - >> not only is it meaningless, but it can put excessive wear on the drive. >> > > Actually, Microsoft has a knowledge base article about precisely this, and > they state that the best possible place to put a swap file is, in fact, an > SSD. Once created swap files don't get written too very much... most of > the access is reads, not writes. Besides, I have had mine for almost three > years now with no problems. It will probably last another two or three > years ...or more, and by then I will get rid of it for the next great thing > ... maybe a speed of light drive! > > Another surprising thing is that SSDs are not that good for video > editing.You would think they would be, but there are just too many writes. > I have tried it and found it to be no better, if not slower then my Raptor. > My experience has been that the best thing to use for video editing is a > Ram drive, although a Raptor or Raptor RAID zero with lots of system RAM is > pretty damn good. >
