Problems with Graid external 2tb HD

Hey Guys got a question you might be able to answer. First of all my specs

System 1
Q9550
Asus p5e3 Premium MB
8gb Ram
Vista 64bit
&
System 2
Q9650
Asus P5E ws
6gb Ram
Vista 64bit

Now to the problem. I am using a GRaid 2tb hard drive. On the first system and it freezes up everything for about 20 seconds every 30 seconds or so while editing(conected via esata). On the second system same connection same software same updates i have no problems. I tried hooking up the drive via firewire to system #1 and can edit and transfer files etc.. without any problems.

Any ideas? I'm about to go and buy another esata card because firewire isn't fast enough to edit multiple HD streams at once.

Thanks Alot