Hey..
Have been reading this thread past few days...am going to be really judgmental. Not sure if I have that authority. Well below are my comments:
LOL so u think u can run a i7 965 + HD5850 CFx on the Gigabyte 460W...
If so, then u hav a lot to learn about power supply, TDP and their affect on product life, dependency on cabinet temperature filter and cooling, the overall life of the entire system and so on.....
Why is this configuration even mentioned. The OPs system/future purchases are far from this. Does not make sense quoting i7 and 5xxxx (and that too Xfire)
I was as ignorant as u one day...then a guy nickamed(he's a god) "Sorcy" taught me about Power and PSUs..bah ...humbug
Yes, we all have gained knowledge somehow/somewhere. Though that does not mean, we got to be sarcastic to others about it.
LOL imagine a Core i7 and HD5850 X2 on a rig for browsing....


FYI - 'm not 15
Again no need to quote a configuration that is not even remotely to the OP.
I am just not that sure about the coolermaster 460W Real Power Pro (the one to go for rather than extreme power) or VX450 Corsair. What is the maximum power that can be consumed on the rig ?
Let's say what would be the total power draw for all the components
Processor (OC'ed)
Motherboard + RAM
GPU (Oc'ed)
HDD ( 1 or more , depending on disk capacity)
Optical drive under load (DVD burning process / Continuous data transfer)
Cabinet fans
let's say Tech_wiz has a system suggested in here with either the real power pro or vx450, what would be total load on the PSU ? Its better to have some headroom for more juice, just in case. As techalomaniac suggested, a 650W PSU would be really the most one can need, even if you have dual GPU's and loads of HDD's.
I know im being paranoid by including the fans and optical drive
Well Xeno, I have a saying "better to be paranoid then sorry". So lets draw up a power requirement chart for the OP:
CPU: 115W
RAM: 5W
GPU: 140W
HDD: 70W (2 @ 35w)
DVD - Burner: 15W
120MM Fan: 10W (2 @ 5W)
------------------------------------
Total: 355W
So as per this (and I have taken all upper limit approximations), a VX450 should be perfect for the OP. He still has head room for future plug-ins to his rig.
But I agree with you, a 650W supply is the better choice. With that, he will never have to live on the edge. With a 450W supply, once a couple devices are added, he will immediately reach his threshold. +++ As a rule with power requirements (be it PSU or UPS), the design should always have a +30% leeway to compensate for efficiency, heat loss, and future proofing.