Installing new drives in HP Compaq dc7600

tray8t

TS Rookie
Hello.
I am considering installing 2 new harddrives.
1.Agility 3 OCZ Solid State Drive 120gb
2.Seagate Barracuda XT 2TB 7200 rpm

I am currently on a WDC WD3200JD-22KLB0 320gb

Both the new harddrives are sata3,6gb/sec

Can I use both new drives,with no reduction in performance ?
Mainly for online gaming.:)