These days any decent motherboard has some sort of RAID controller built into the chipset or added on as an extra controller. This means that the only cost of running striped or mirrored RAID is the price of the second hard drive. RAID 5 is a different game as you need two extra drives but nForce4 for Intel supports RAID 5 and Silicon Image has offered driver updates that add RAID 5 to its integrated controllers during 2005, so even RAID 5 doesnâ€™t necessarily have to cost a great amount. The question is, what benefit does it bring and do you get better RAID performance if you buy a dedicated controller card instead of using the integrated â€˜freeâ€™ chip.
We decided to check out the current state of RAID for PCs and assembled a test system.
We used an MSI P4N Diamond motherboard with nForce4 SLI chipset, a Pentium 4 processor model 670, running at 3.8GHz, 1GB of Samsung DDR2 667MHz RAM in two modules to give dual channel and Windows XP SP2.
We ran three sets of tests, first in a single drive then in numerous RAID configurations. The initial test was HD Tach, a theoretical benchmark tool for evaluating the average read/write speed of a hard disk and its maximum burst speed, though this latter figure has very little bearing on real world performance.
The second set of tests was a set of our own file transfer tests and the third set was PC Mark.
To begin we attached a WD740 Raptor drive to the integrated Sil3132 controller and ran HD Tach. We then used this as a source drive for the file transfer tests so the source hard disk wouldnâ€™t be the bottleneck
Next, we plugged an unformatted 400GB Seagate 7200.8 drive into the nForce4 SATA controller and ran HD Tach 3 to give us read, write and burst speed figures.
For file transfer speed testing, we formatted the Seagate and wrote 4GB of files from the Raptor to the target drive and then we renamed the files (to avoid caching) and read them from the Seagate back to the Raptor and timed the transfers to give us a real world test.
After that we unplugged the Raptor and installed Windows XP on the Seagate and then installed and ran PCMark05, including the HDD test.