I recently bought 2 x Seagate 7200.11 500GB drives and have them in RAID 0 configuration.
They were about good for 3 weeks, but now they behave erratic. So I backed up my files, deleted the RAID and hooked them up as individual drives and ran SeaTools tests on them and they all passed with no errors reported from SMART.
I then re-raided them wioth 16kb strip size, re-installed windows and application and defragged with PerfectDisk 2008. It all seems fine now, but when I run a HDD Tach test it still shows very erratic performance, I notice this performance hit when I run games or other applications.
Have a look at this graph:
Is there any reason it would behave like this? Might one of the drives be failing? Why is it spiking like that?
You should re-strip to 128k (or whatever is default) which is the best performance for desktops. Then, use HD-Tune for your benchmark because you can set the strip size which will give you a more accurate benchmark. The spikes you see won't happen as much and your read/write averages will go up. It doesn't surprise me that games and other apps seem slower with a 16kb stripe.