Lexar 80x flash RAID?

scalar · Post by **scalar** » Thu Dec 23, 2004 5:14 pm

Has anyone tried making a striped RAID array with Lexar 80x flash?

http://www.lexar.com/digfilm/compact_flash.html

This appears to have an effective speed of 12 megabytes/sec (96mbit/sec) per card.

I'm thinking that by setting it up with an IDE RAID controller, striping data across four of them in 4kb blocks may bring it nearly up to the performance level of firewire (384 mbit/sec).

As a network admin I know that a typical system rarely needs more than 4 gigs of space for Windows, MS Office, and some other apps, so it may be possible to build a fast and completely silent storage system with these cards.

-Scalar

ddrueding1 · Post by **ddrueding1** » Thu Dec 23, 2004 5:49 pm

DOn't forget that there is a limited number of times any part of a CF card can be read or written before it fails. I don't know the number exactly, but I know it wouldn't last more than a year of normal use unless you made some sepecific OS config changes (disabling virtual memory, etc.)

Becks · Post by **Becks** » Wed Dec 29, 2004 5:46 pm

Yea this is a neat idea, no one ever seems to try it out tho heh.

The problem is the number of writes... form some other post about this...
"A compact flash card is good for about 500,000 writes per sector. Industrial strength cards suggest about 2,000,000 writes per sector."

Dunno wtf industrial strength cards would be heh... but 500,000 writes is quite a bit... unless you have something being updated very often... almost a non-issue within 2 years or so. heh hell every year you could sell them on ebay (even if you use up 1/2 the writes no one will ever care.... who's going to take 200,000 pictures) and buy new cards.

You could have a networked drive where you stored often used things... over GbE it wouldn't be that slow. Most of my storage is on a linux computer int eh closet running samba... its kinda slow sometimes (when having to read alot of data, only 100mbit lan) but watching movies/playing music off it is fine... having all my documents and whatnot on there is not an issue.

Windows lets you pick where it uses temp/cache folders.... not sure if you can pick a networked drive or not.... but that would let you get those high write fiiles off the CF cards.

It'd be neat to see it done one day heh.

Becks · Post by **Becks** » Wed Dec 29, 2004 5:51 pm

OH yea it would be kinda expensive... so if you have the money... if you get one of those nicer raid cards with a empty slot of some sd ram for cache.. i wonder if u stuck 128/256MB on there if a file is being written to often the writes will be done to the raid's cache and cut down on the writes to the cf cards... dunno but whatever.

--edit---

also not sure if you can increase windows write behind cacheing for harddrives...
http://www.winguides.com/registry/display.php/55/
thats a start i believe...

also windows would let you use a networked drive as your swap file...
http://www.somacon.com/blog/page23.php
theres aplace testing it... using not hte nicest gbe cards... the intel ones actually perform alot better... they also test running a ramdisk on the samba server and using that as the swap on the windows client... kinda neat as well heh...

anyways if windows is happy with a networked drive as swap it shouldn't care about putting all its cache's and temp folders on a networked drive... that would be pretty cheap to do if you have another computer in the house.. $100 for 2 nics (Intel PRO/1000 MT)and use a crossover cable if u want to be cheap.. or another 100$ for a gbe switch... (jumbo packets help alot but not sure if windows will use them).

ANyways... hehe does make me want to switch to GbE when I'm moving files around and my network is maxxed out.

MoJo-chan · Post by **MoJo-chan** » Thu Dec 30, 2004 1:22 pm

You can disable the page file in Windows XP, but not in 2K. As long as you have about 512MB of RAM everything, even most games, should run fine. The page file is what chews your HDs the most. A compact flash card should last at least a few years without one.