5770 crossfire and 52A on 12V+

kaspro

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Hi, i just bought a sapphire 5770 and i thought that 600W is recommended for the crossfire, but then in alot of forums and a review i saw before i saw that the minimum 12V+ of the PSU is 55A, so my current PSU that i bought for this rig produces 52 on two 12V+ (30 + 22), so will that be enough for the crossfire

my current config:
CPU: AMD Phenom II X4 955
Mobo: Gigabyte 890GP
RAM: 4Giga DDR3 1600
1 HDD 500G SataII
1 DVD-RW
2 120mm Case Fans
 

kaspro

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but here's what it says in the link that ortoklaz just posted.......
That power supply needs to have (in total accumulated) at least 55 Amps available on the +12 volts rails.
which means the do calculate the total of the 12V+ amperage
 

skolpo

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You do not add the two rails together to get the total amps from a power supply. You take the 12v Watt output and divide it by 12. In your power supply, the output is 504. 504 divided by 12 is 42. You have 42Amps in the 12v rails.
 

skervy

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like the other few said should be fine with a quality psu. i seen this all over the place when i was picking my power supply. my future plans are to crossfire 5770 to so i picked the specs based on that. there is alot of setups with a 650w 52amp antec corsair yada yada working fine according to users. yours looks nice spec wise 80+ pfc so on and has 2 pci-e so your prolly good to go. even says on the table supported devices grtaphics card on each rail. if what the other guy said was correct about 10 amps you still have 12 left on the 2nd rail for the cpu er however that works i dunno :p sorry i started smokin half way into this post and rambling now lol

oh and to the other guy hes not being rude at all when your going around telling someone to purchase a 850w 170$ psu for crossfire 5770 lol
 

Timop

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Youll be fine, dual 5770s take ~160W and the CPU maybe ~120W OCed. Which runs you less than 300W on high GPU/CPU load.

Though Hec isn't the best company around, its high-end line is still capable of providing its rated power for the most part.
 

Timop

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^Thats the usage for the whole system, including the Mobo, GPU, Hard-drives and without factoring the PSUs efficiency, which proves my point that the stock 955 barely uses 100W on load.

Heres your picture by the way, it says with a 3.8Ghz i7, the whole system uses barely 370W on load. HX850 much?
2983_27.png
 

Timop

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HDDs use 5W each, fans barely use 3W and heatsinks use no electricity at all.

Unless you plan to run a RAID farm in your case (it only hold ~6 in most cases) or drill holes for a wind tunnel (usually a case holds 5 fan MAX at stock) the added power would be less than 45W.

Real world usages will be even lower due to the fact you will rarely read all 6 drives at the same time and 5 fans running at full speeds is pretty unbearable after a while.
 

ortoklaz

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the 850 was from top of my head ok ?"what PSU would you recommend guys?!!!!!! " you could post your favorite to, this is not the point..you guys get so technical and all this and that..but next year when he would want to upgrade to a lot more powerful set up,insted of spending 100$ extra now he will spend 250+
 

Timop

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Why? PSUs are not gonna magically increase in price next year.

Besides, Spending $250 now then $100 later is the same thing as spending $100 now and $250 later, with the second option he might even get better/newer products.
 

ortoklaz

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why in a year? because CF5770 is not that great,it's basically 5870 and there is more than GTS450&460,but you don't care you just want to prove that you know more