With the recent HD video editing I’ve been doing, I’ve been on the performance hunt. My old Asus A8N-E setup had two Western Digital WD1200JS SATA II hard disk drives, in a RAID 0 configuration. I ran three tests, all straight after booting, and HDTach gave me these average readings:

Burst: 148.3 MB/s
Average read: 95.6 MB/s
Random access: 18.7s
CPU: 7%

This seemed low to me, considering that SATA II has a theoretical maximum of 3Gbps = 384 MB/s. I asked online about this but was told that this was normal.

I still wasn’t satisfied, though. I was suddenly struck by something I read – the Asus A8N-E has two onboard SATA controllers, one for ports 1 and 2, one for ports 3 and 4. Now both my hard drives were connected to SATA ports 1 and 2. What if I switched one drive to the other controller? I opened up the case and changed the configuration to use to ports 1 and 4. Restarted and ran HDTach, three times as before:

Burst: 276.6 MB/s
Average read: 106.0 MB/s
Random access: 18.7s
CPU: 5.3%

Yes, I couldn’t believe it either. Burst speed went up by over 83%! More importantly, the average read went up over 10% – a significant boost. CPU utilisation also appeared to decrease, but this could be normal variation.

So if you have an Asus A8N-E and want to optimise your RAID configuration – check your drives are making full use of both available controllers. Of course, usual caveats apply – make a backup, etc. RAID arrays have a nasty habit of exploding, slaying all.