2 tb array - 5 x 500GB in RAID 5

[marcosscriven]

Hi Guys

I am looking to create a RAID array, and wondering what disks to use? 500 GB seems to be the sweet-spot, at around 13 ppg (pence per gig). 750GB is around 17 ppg, and 1TB 19.7ppg. Looking at it this way, 1tb HDs are 50% more expensive.

Are there any mobos out there with decent real raid capacity for 5 sata disks, hot swapable? If not, what controller would you recommend?

Ta

Marcos

 

[rpstewart]

The main problem with mobo RAID5 support is that there aren't any boards out there with any form of hardware acceleration for the XOR parity calculations so the write speed will be poor - about 15-20Mb/s. Your next issue is going to be finding a board with 5 ports on the same controller, some of the P35 boards for example. However I'd recommend staying away from onboard solutions, even for storage the write speed isn't up to it for a 2Tb array.

The big question is what the array is going to be used for, if it's simply storage then something like a Highpoint RocketRaid 2320 will be fine, it isn't true hardware RAID but it's better than onboard - I get between 60 & 80Mb/s writes from mine. If you want to boot from the array as well then a decent write speed is vital so you'll need to look at some of the proper hardware cards from Areca, Adaptec or the like but expect to have to shell out £300+ for an 8 port one.

In both cases you'll need a free PCIe slot, 4x for the Highpoint or 8x (so a 16x slot) for the Areca or Adaptec.

 

[Dimension]

Your write speeds will not be that slow with a decent CPU

I had a RAID 5 array running for a couple of years on 5x 250gb maxtors and got consistent 50mb/sec write speeds on file transfers. I maxed out my raptors testing the read speed from the array at 60mb/sec
This was using a Windows software array on a dual xeon 2.8.

If your building a file store which will only see large file transfers then any software RAID card will do

If you want fast random I/O & decent feature set such as faster rebuild and hot swap I would look at the areca 1210 or 1220 series cards, these have fast processors onboard that take care of all the parity calculations. you should see read and writes in excess of 100mb/sec with one of those