Ante, just saying... save yourself the headache in a few years and get a new PSU. One that's been in service for 4-5 years + an overclock (albeit a modest one) is prone to random failure. You'd do yourself a great injustice to not just shell out a little more cash on a new power supply especially considering the weight of the new parts your putting into it.
Welch, that is very good advice indeed, thank you. In fact, the above scenario already happened - but thankfully it happened a few months ago! One day, after about 4 years of service, my OCZ 780W power supply (the one still in my signature below) simply could not supply enough juice to reliably power up the system any more. It would only turn on every third or fourth time I would press the power button! I bought a new, modular 800W PSU from Cougar, a German brand apparently only sold in Europe (I bought it in Germany).
As soon as I replaced the old OCZ PSU with the new one, my system started working flawlessly again. It still does, it just got really long in the tooth.
I forgot to update the PSU in my signature...
Regardless, you were absolutely right about the PSU getting flaky after this many years, Welch, thanks very much!
Asus P9X79 Pro, firstname.lastname@example.orgGhz w/Corsair H80, 16GB Corsair 1600MHz RAM, OZC 256GB SSD + OCZ128GB SSD + 4x Seagate 2TB, 2x Gainward GTX 670 2GB in SLI, LG GSA-4120B, Terratec Cinergy 2400DT, Cougar GX 800W PSU, Thermaltake Armor, Dell U2711