RAID 0 or 5 for Gaming

[JrFowler]

I am about to purchase a new gaming system, consisting of an e6300 and DS3 gigabyte mobo, 2gb of OCZ memory and I will also be running a 7800gs OC'uk card,

something im not sure about tho is the drives..

I have read in micro mart that the best performance out of hard drives u can have is to have them in a raid 5 array, consisting of 4 drives in this array, but on here I see you all talking about raid 0..

Would anyone care to explain the difference and in particular which array is better for the gaming system and do the arrays really make that much difference?

thanks

 

[Dist]

RAID 0 only stripes the data, so performance is increased at the cost of loosing any hdd means compleat loss of data.

RAID 5 is the same as raid 0, but generates parity information which means you can loose 1 hdd in the array, and use the remaining hdds to reconsturct the lost data onto a new hdd.

if you use onboard raid, then RAID 5 will use a bit of CPU usage as it has to calculate parity information when writing to the array, if you buy a RAID controller then that cpu usage is put onto that controller so shouldnt be a problem. Due to RAID 5 using parity information to allow failure of a single HDD, files will take up more space since not only does the file data have to be saved, but the parity has to be saved too.

 

[rpstewart]

RAID5 can give stunning performance but only with the right kit. To ensure redundancy in the event of a drive failing a RAID5 array consists of blocks of data and parity information striped across a minimum of 3 disks. If one drive fails the data blocks it contained can be recreated using the remaining data blocks and the parity information from the other drives. The problem is that the parity data is created by performing an XOR calculation on all the data for the corresponding block - this takes a lot of processing power. RAID5 is available on a lot of Nvidia and Intel based boards as an onboard solution but this relies on the main CPU for parity calculations. As a result the data write speed can be very low, about 15-20Mb/s accompanied by high CPU usage - certainly not ideal. If you want decent performance then you need to buy a dedicated controller card but a good one (Areca etc) will set you back upwards of £400. This buys you a dedicated XOR engine which removes the CPU overhead and can give you writes in excess of 100Mb/s with decent drives.

Now RAID0 is a lot simpler, the data is evenly spread across the disks in the array with no parity and therefore no redundancy - if one drive fails ALL the data is lost. Since there's no parity there isn't the performance hit in writes and the read speed is on a par with RAID5 (upwards of 100Mb/s with 2 drives, more drives = more speed but more risk of failure). You also only need 2 drives for RAID0 vs 3 for RAID5.

There's a lot of differing opinions on whether RAID0 is worthwhile for gaming, some folk swear by its ability to load level data quickly hence giving them a bit of a head start when playing online. Others don't like the risks or have been burned by failed arrays and prefer a single WD Raptor which uses a high spindle speed to give very quick access times.

The problem is determining the real world performance as opposed to benchmarks is difficult. Personally I've tried both RAID0 and single drive operation for my boot disk and I can't see much of a difference but then again I don't game much and only reboot occasionally so boot times to me are fairly irrelevant.