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Paging File on a Compact Flash is Fast

Last response: in Storage
January 27, 2010 1:47:51 AM

Hello everybody!

I just made a cheap and efficient improvement, it may be useful to others.

The computer I presently use relies often on its paging file, because its i815ep chipset accepts only 512MB Ram, and W2k+Comodo+Avast already eat up 300MB. Firefox alone still fits in the remaining room, but not together with Google Earth for instance. And Ski Challenge alone is too big.

Sure, more recent machines have more room, but software developers have worked hard to use it up, haven't they? So using the paging file is still rather common. Just scale up all sizes accordingly.

I thought Windows would read and write many megabytes at once in the paging file, so only contiguous throughput would matter at the medium, and a mechanical disk would be best. But then I tried a Compact Flash card on a P-Ata adapter, and put the paging file there, and it's much faster.

This is observed when switching (Alt-Tab) between a big video game and the Explorer, or Firefox, or Internet Explorer... With the game using all available Ram for some time, the Hdd needs at least 5s to restore other applications (how boring!) while the CF does it in less than a second.

The Hdd is a J8080, same design as the 7k160, (among) the fastest P-Ata available. The best Sata have improved on it, but the J8080 is still as good as most of them.

The CF is a Lexar 300x 2GB, quite a good SLC, which cost me 17 euro. A Transcend 266x or an A-Data 266x would be equivalently fast. Here as well, CF with 600x speed exist, but I didn't try them, and they seem to be MLC with bad access times. The paging file can also be split among several CF.

Measured with IOMeter on 100MB space with 1 request at a time, random read and writes are:
176 io/s and 433 io/s for 4kB files on the J8080, but 4750 io/s and 46 io/s for the Lexar 300x;
19 MB/s read for 128kB files on the J8080, but 43 MB/s read for the Lexar 300x;
contiguous read and write is 78 MB/s on the J8080, but 44 MB/s and 33 MB/s for the Lexar 300x.
Also interesting is that a paging file won't update the directory often.

Win2k (and W95-98-Me) accepts to put the paging file on a removable media, like the Lexar and Adata CF. I believe Xp requires a fixed media, which would be fulfilled by the Transcend.

Putting Internet Explorer's temporary files on that same CF may improve also. I'll give a try.

And if the CF trespasses from the many writes, it's only 17 euros. SLC last long anyway.

This makes a quick, efficient and affordable improvement, especially for older machines but not only.
a b G Storage
February 11, 2010 11:48:25 PM

You should also take a look of YouTube videos recorded by people who run practically launch all their apps at the same time, but everything still moves quickly. Their secret sauce is that everything's on an SSD, which is also flash-based media with a faster and more direct connection to the rest of the computer.