Yet another will my psu question do thread

BeansBeans

Righto will be building a system along these lines. Wondering which power supply to go for.

Phenom 2 X3 720 BE
1x Samsung 1tb f1 HDD
MSI 790FX-GD70 mainboard
4Gb OCZ platinum DDR3
Sapphire 4890 Toxic crossfire
Noctua NH-U12P cpu cooler
Probably an SSD a few months down the line (although i assume that wouldnt be an inffluence).

Bear in mind i will probably overclock the cpu to 3.2Ghz-3.4Ghz obviously see how it goes. Nothing major.

The main issue is adding another 4890 toxic over the next few months. I will overclock both cards. Apparently no problem going over 1000Mhz with those cards.



So will a Gigabyte GE-S800A-D1 ODIN GT 800W Power Supply Unit Do the job or would i be better off with a Corsair hx850.

These are the 12v rails on the Gigabyte +12V1@18A,+12V2@18A, +12V3@25A, +12V4@25A
The Corsair has only one +12v@70a (isnt multi rail a good thing?)


The reason im interested in the Gigabyte is the low price and low noise. It got a great review off bit-tech as well so sure why not (also love Gigabyte for some reason).
The Corsair is less of an unknown but pricier and its not noted for being quiet.

I realise going on about noise may seem ironic when im intending to use 2 4890 Toxic but i will leave it on as i sleep so will stick in a fan controller too and dont want the psu fan to be whining away (girlfriend will murder me).

So will the 800w Gigabyte be fine or will i want the Corsair hx850. Surely i wont need anything larger will i?



Sorry for the incredibly long winded post (late at night with rum on board). :rolleyes:

StopNotWorking

A good 650w PSU would hold all that up fine. In short yes OP your PSU will do fine.

BeansBeans

StopNotWorking wrote: »

A good 650w PSU would hold all that up fine. In short yes OP your PSU will do fine.

A 650w would be running rather tight wouldnt it?

Anyway thanks for the input. I think ill go with the Gigabyte.

StopNotWorking

Mmmm tight enough. I can't see it pushing 500w. If you wanna go better safe then sorry then do. I have a corsair 750 and its a great psu. Very messy though, try get something modular if you can. See the picture thread thats been stickied. Modular is really the way to go.

BeansBeans

StopNotWorking wrote: »

Mmmm tight enough. I can't see it pushing 500w. If you wanna go better safe then sorry then do. I have a corsair 750 and its a great psu. Very messy though, try get something modular if you can. See the picture thread thats been stickied. Modular is really the way to go.

Ya im not entirely sure on the requirements of all the parts but i remember reading a similar example system needing a 500 pre crossfire, with the second one adding another 200w. But then the fact the two cards and the cpu would be overclocked are throwing me off.

Although that could be a 4870x2 in which case i blame my memory for my idiocy.

Im a little thrown off by the the single rail on the corsair.

Theyre both modular the Corsair TX are non modular, HX are modular. My last psu was modular as well, i certainly wouldnt go back to the mess of cables. I find cable management a horrible chore so any shortcut helps. Actually one reason i was thinking of going for a Coolermaster CM690 case was the cable retention clips built in, haha.

I am in a permanantly confused state about PSUs.
My original intention was to go for a BeQuiet 700w ill probably just order one of these before i change my mind again .

Thanks again.

marco_polo

BeansBeans wrote: »

A 650w would be running rather tight wouldnt it?

Anyway thanks for the input. I think ill go with the Gigabyte.

If you were adding in a second HD4890 later better to go higher than 650W. In fact a word of warning my Corsair 650 wouldn't even have enough power connectors for two cards (only 2*4 connectors) so I presume there is a fair chance others PSU in the same range would be similar.

StopNotWorking

A few "sli ready" PSUs wouldn't have enough connectors for two 4890s. They need in total 4 6/8 PCI-E cables right? My 750 has enough but ATI package molex-pci-e converters so you could hook a second one up. Dodgy though.

Solitaire

+1 on the 750W - those Toxics have a higher power requirement than normal HD4890s and also have one 6pin and one 8pin PEG connectors instead of two 6pin :eek:

great

I out all your info into the pro psu calculator here and it gave this result... if u want me to change any of the parameters just reply back and ill do it tomorrow

BeansBeans

Thanks all for the help.

Looks like ill grab the Gigabyte Odin.
There are two 6+2 pin PCiE connectors, and two 6 pin PCIE connectors, so fine for 2 cards.

Oh the PSU calculators.... I dont entirely trust them to be fair. Although the cpu wattage seems fairly accurate. But the voltage would probably be about 1.475 for that overclock if i remember correctly.

Actually some solid info on this issue here guru3D have never really taken notice of that site. But they made it clear in simpletons terms for me there. Additional ones of these cards 190w = 16 amps per card.

Sorted thanks

Solitaire

I have one thing to say about the Overclocking Result: LOLOLOLOLOLOLOLOL

Ignore the Calculator, its results have no grounding in real life. I particularly love how it assumes that every Hertz increase past stock apparently doubles the current draw of the device. Semiconductor Maths Fail FTL.

And guru3d are also talking horse[CENSORED]. 190W/12V ~16A. Fine. But what idiot thinks a HD4890 needs 190W?! What was that? AMD? Oh, ignore them, they've been barking mad for years

BeansBeans

Good to know. I assume the toxics wont have a huge difference.