PSU rating for mobo/cpu

I have recently upgraded (open to debate), to an Intel I5 3570k setup. I am carrying over my 700w OZC Stealth Xtreme II to this setup. I am giving my old kit to my children whos C2D 6320 gave up the ghost. I have spare, an Aopen 450w PSU, would this be enough to power the following, all at stock speeds: AMD Phenom II 1090T
AMD HD5770 Gfx card
ASUS M5A87TD EVO MOBO
4 Gig Patriot Gamer 1600Mhz Memory
1x80 gig sata 2 and 1x 250 gig sata h/d
1 x dvd writer.
If I disabled 2 of the cores in the bios would this help with power management?

My neighbour did give me an Evolabs 750w psu he had lying around (unused). Not knowing who this company is, I'm in two minds whether to use this instead.
Thanks in advance.

Have a look at these power calculators
ASUSTeK Computer Inc. -Support- Recommended Power Supply Wattage Calculator
Thermaltake Power Supply Calculator
they should tell you exactly what you need to know

The Jockster said:

My neighbour did give me an Evolabs 750w psu he had lying around (unused). Not knowing who this company is, I'm in two minds whether to use this instead.

If it is this I wouldn't touch it with a barge pole. Not 80+ certified, very cheap, unknown brand. More often than not, those things are utter rubbish that melt down when asked to provide more than 400W.

The 450 W one isn't a better company either, as it is the same as above but adds 7+ years on top.

If I had to choose I'd go with the 700w, but just because it is newer and that setup shouldn't need more than 550W (eyeballing). Check the calculator Jockster provided to see how much power you need.

If I disabled 2 of the cores in the bios would this help with power management?

yes, but it's not worth it imho.

Thanks for the replies. Well Im not feeling lucky, so I went ahead and ordered a 600w Corsair 600CXM fm Aria in the UK. Again, thanks for the help

A good choice.

bobkn said:

Sapphire (www.sapphiretech.com) recommends a minimum PSU of 500W for a single 5770. They don't specify a +12V current requirement, so that makes it harder to distinguish between good and bad 500W PSUs.

That seems absurd for a card that has no auxiliary power connections (<75 W max permissible power draw through the PCI-E X16 slot), but I'm not in a position to argue.

While card manufacturers tend to ask for 100-150 more watts than necessary as they don't know the rig and have to tell something they are sure will work with most rigs, that card does have a 6-pin auxiliary connector as it needs around 110 watts at 100% load.

Heck, even the 4670 in my rig has an auxiliary power connector (a molex).