Flash Memory for Swap file?

[Fabio]

I'm thinking about using my 4gb SD card for my swap file. Will it work? Flash memory via a USB 2.0 connection is faster than a 7200rpm HD right?

What are your thoughts?

 

[wanderer27]

I've been thinking about this myself lately. From what little looking I've done so far, it appears that transfer rates on SATA's are far faster than most USB Flash drives.

I probably need to look into this more though . . . .

 

[John]

It would be a bad idea.

[*]Your internal HDD should be much faster than a flash memory drive thru a USB 2.0 port
[*]Flash memory can only take so many writes, and swap will get through them in a very short period of time
[*]If you have enough system memory you won't be swapping that much anyhow

Leave the swap file alone and let windows manage it.

darn typos

 

[Ruptga]

I'm going to try the same thing soon, probably around Christmas.

It should be faster because the latency for flash is on the scale of a thousandth of a HDD's, even though the theoretical transfer speed is lower (480Mbps etc). If you have a 133x SD card, that comes out to 159.6Mbps (if the wikipedia page hasn't been vandalised recently). If you have an 80x SD card, the maximum speed should be 96Mbps.
Superfast HDDs like a Raptor will get something like 110Mbps of real burst throughput. The speed issue doesn't matter to me, because even if my flash card has lower transfer speeds, it has got to be better than my laptop's HDD.

The only real issue is how long the flash card will last before it dies. But you can have multiple swap file locations, set one for your flash and one for your HDD. My idea is that if the flash unexpectedly craps out, the computer will probably crash, but boot back up like normal because of the secondary swap file location. Anyway, wikipedia has a bit about how long flash should last. "most commercially available flash products are guaranteed to withstand 1 million programming cycles" I don't know how long a million cycles will last you, but it has been said that realistically that will be several years.
http://en.wikipedia.org/wiki/Flash_memory#Limitations

Just about forgot this, Vista will support this feature natively, and they'll be selling certified USB drives specifically for this purpose. It may be worth it to wait for the official stuff, then again it may only be a good idea for the paranoid, I really don't know how long flash will realistically last when used as an HDD.

 

[Goi]

Actually the MTBF of several solid state drives using nand flash are an order of magnitude higher than magnetic hard drives. I'm not sure about sd/cf and other flash media though. Transfer rates are indeed slower, but on average the access time is also an order of magnitude faster, but that depends on the flash media itself. I've seen figures ranging from like sub ms to around 60ms, so YMMV.

 

[Ruptga]

I have no idea what YMMV is, but that first part about lasting longer than HDDs is certainly interesting since it's the exact opposite of what everyone else is saying, where did you read this?

 

[Goi]

YMMV = your mileage may vary.

As for the first claim, just check out the specs of any SSD and compare that to the specs of a regular magnetic HDD. The former is something like 1M hours while the latter is usually about 300-500K hours.