PSU's... Power vs Make... What is sufficient?

[adam1712]

Okay so this is my proposed system...

Phenom X4 965BE @ 3.2 (Possible o.c to 3.6/3.8)
2 x 2Gig RAM DDR3 1333
Radeon 5770 (Future plan to xfire)
I think the rest is innaplicable?

I am building this pc via PCSpecialist and i have come down to power choice... i know 650W is more than enough for the basic system but if i was to crossfire AND overclock the CPU and possibly the GPU's would i need to for for an 800W psu? This is what i really need to know but also... The 650W is corsair whereas the 800W is presumably a less reliable brand... I know these both come down to one being more powerfull but would the fact the 650 is corsair come into the decision at all?

Put simply... If using an mildly oc 965BE and crossfired 5770's should i go for a corsair 650W PSU or a 'unbranded' 800W PSU? Thanks

 

[hunter315]

What 800W PSU are you looking at? unbranded doesnt tell me anything about the quality, there is so much variation in quality. At least fine out what the current rating on its 12V rails is.

The 650W corsair will be powerful enough to handle crossfire and overclocking, if the 800W unit is a super crap unit then it might not even be able to handle a single 5770, it really depends on the unit.

 

[adam1712]

What 800W PSU are you looking at? unbranded doesnt tell me anything about the quality, there is so much variation in quality. At least fine out what the current rating on its 12V rails is.

The 650W corsair will be powerful enough to handle crossfire and overclocking, if the 800W unit is a super crap unit then it might not even be able to handle a single 5770, it really depends on the unit.

Thats what i mean... Im new to pc building stuff and i have done a hell of a lot of looking into this stuff but PSU's is one thing i am clueless on, all i know is that corsair is a good make and a lot of people favour lesser power good brand over more power for cheaper. I dont know what you mean by the rating but i doubt i could tell you anyway... It doesnt give a make or model it just says 800W Quiet 80 PLUS Quad Rail PSU + 120mm Case Fan. But if your telling me i will be able to crossfire and overclock on the 650 corsair unit i will go for that, will it deffinately be okay? Thankyou by the way very helpfull.

 

[iam2thecrowe]

Its similar to speaker/amplifier ratings. Some marketing ploys will claim 1000w, 6000w! etc. but really theyre more like 20w RMS (continuous power) when you look at the details. Also the quality of components like capacitors etc. is not up to scratch in cheaper brands. They will not last for the long haul. Stick with well known brands like Antec, Corsair, Silverstone, thermaltake etc..

 

[adam1712]

Thanks for the advice guys realy helpfull! I sort of get the deal with a good quality PSU now compared to a cheap one, i will get the 650W Corsair, thankyou!

 

[unknown_13]

Yes don't waste money on 800W PSU's for 2x5770's