old HDDs ideas

quantumisation · 24 Feb 2007 at 20:49

i currently have 150gb and 250gb sata-1 HDDs but in my new system im looking for max speed and fault tolerance, so i was thinking about a raid-5 setup. my plan is to get something like 3x 300gb sata-2 drives, then allocate a small 50gb partition to the O.S and the rest to data storage. Just wondering what people think of that setup and where i could fit the old drives in. Ive not bought anything yet and its just an idea but im open to something better

rpstewart · 24 Feb 2007 at 21:24

Don't consider RAID5 for a boot drive unless you're willing to spend £300+ on something like an Areca 1220 card. The write speeds provided by motherboard based RAID5 are too slow for decent performance, task swapping and any other page file writes are excruciating.

You'd be better off going for a couple of decent HDDs (Seagate 7200.10s for example) in RAID0 and using your existing disks for backups.

naro · 25 Feb 2007 at 01:28

u might want to use your old system as a file server or something like that..

quantumisation · 25 Feb 2007 at 02:07

nah cant do that the old computer is getting given to someone. Its got a 3rd old IDE drive that i dont want so theyre getting that. I might do the raid0 2 new drives and use old drives as storage idea..although 350gb wont be enough so id end up having to buy a 3rd drive anyway. Why cant i do raid 5 without a controller card, looks to me that theres onboard controllers that can perform raid 5?

Davey D · 25 Feb 2007 at 08:33

quantumisation said:
..... Why cant i do raid 5 without a controller card, looks to me that theres onboard controllers that can perform raid 5?

none said you cant do raid 5 with onboard controller :rolleyes:

it was said that you will get a performance hit, since the controllers on mobo's aren't the best devices out there

rpstewart · 25 Feb 2007 at 09:44

Davey D said:
none said you cant do raid 5 with onboard controller it was said that you will get a performance hit, since the controllers on mobo's aren't the best devices out there

Holy huge sig Batman! 400x75px max plus one line of text please.

You're correct though. RAID5 provides redundancy by splitting the data into pieces, 2 for a 3 disk array, 3 for a 4 disk one etc, it then calculates a parity block based on an XOR calculation of the data blocks. The calculation of the parity is very CPU intensive and in mobo based RAID5 implementations this has to be done by the main CPU. As a result write speeds are severely limited (~15-20Mb/s) and CPU usage is very high.

quantumisation · 25 Feb 2007 at 10:23

thanks i had forgoten about the cpu usage for onboard so yea raid 5 is probably off the table. I thought controller cards werent that expensive but the cheap 1s only seem to do raid 0 and 1. If you implement raid 0 or 1 onboard how cpu intensive is that likely to be roughly? id still like to use raid somehow (maybe a stripe and a mirror)

rpstewart · 25 Feb 2007 at 10:30

RAID0 and 1 don't need any significant processing power behind them because the operations involved are simple so motherboard based solutions are fine.