5770 crossfire and 52A on 12V+

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
30 answers Last reply
More about 5770 crossfire
  1. Yes, it's fine, a HD 5770 needs some 10A max.
  2. Should be no problems, but I'd like to see the make and model of the PSU first.
    Not every unit can deliver what it promises and some makers are known to overinflate (lie) about the outputs of their products.
  3. I think this is legit review ;

    http://www.guru3d.com/article/radeon-hd-5770-review-test/11

    I own 5770 for almost year now...sure it's going to " run" (my previous psu was 650W 38A on single 12v rail) but you wont be playing,it wont be stable..just saying
    If you not going to OC. you will be ok..i guess
  4. Well first of all, your calculations are wrong. You do not simply add the amperage given on each 12v rail and say that's your total amperage. What power supply do you actually have?
  5. skolpo said:
    Well first of all, your calculations are wrong. You do not simply add the amperage given on each 12v rail and say that's your total amperage. What power supply do you actually have?


    but here's what it says in the link that ortoklaz just posted.......
    Quote:
    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
  6. kaspro said:
    but here's what it says in the link that ortoklaz just posted.......
    Quote:
    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


    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.
  7. ^+1
    If you got your mine set on CF or SLI your PSU wont do it
  8. Oh, is that what you think too skolpo that my PSU wont run it, and if that so, what PSU would you recommend guys?!!!!!!
    and Thanks for the help!
  9. dude..you dont have to be rude,just point out what you disagree with
  10. 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
  11. 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.
  12. the numbers on paper are not whats reality ,but if you like numbers here is 955 no oc.
    http://img16.imageshack.us/img16/2196/powerq.png

    Uploaded with ImageShack.us

    http://www.tweaktown.com/reviews/2983/his_radeon_hd_5770_1gb_video_card_in_crossfire/index14.html

    the bottom line is you want good stable power supply,why you want to second guess down the road?
  13. ^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?
  14. ok you ad HDDs +couple fans+nice heatsink+....good luck
    I'm not a hater i'm participater LOL
  15. 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.
  16. im running 3 hard drives, overclocked Phenom II x4 @ 3.68mhz. 3gb of Ram, etc, etc. and iv tested crossfire 5770's on a 650w. works fine. so i doubt you'll have a problem.

    850w is not necessary
  17. 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+
  18. 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.
  19. ct1615 said:
    1. he already has a PSU that will work!
    2. being technical is the point for recommending hardware....it is technology after all
    3. have you looked at the benchmarks for the ATI 5770 CF set up? It runs everything thrown at it at 1080p. Why would you upgrade in a year??
    4. if anything the ATI 5XXX series and the Nvidia GTS 450 & 460 show that cards are becoming more energy efficient.
    5. your last line makes no sense, no clue what you are trying to point out.

    P.S. I think the top of your head needs to be examined :whistle:


    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
  20. less then 6 monts
  21. wow
  22. Get back on topic chaps.
  23. Hey people, thank you alot for help..and i'm sorry that the topic took some aggressive ways..its just everyone want to prove his point...
    anyway i'm sorry now that i've become little confused

    for ct1615 said :
    Quote:
    FYI, your PSU has 42a on the 12v. you don't add the amps together on the 12v to figure out your total. It's based on the watts your 12v provides.

    so now, isnt that little low for it requires 55a on the 12v, or should i care for the watt for the 12v in my PSU produces 500w and i'm not gonna need more than 400w?!

    Thanks alot
  24. kaspro said:
    Hey people, thank you alot for help..and i'm sorry that the topic took some aggressive ways..its just everyone want to prove his point...
    anyway i'm sorry now that i've become little confused

    for ct1615 said :
    Quote:
    FYI, your PSU has 42a on the 12v. you don't add the amps together on the 12v to figure out your total. It's based on the watts your 12v provides.

    so now, isnt that little low for it requires 55a on the 12v, or should i care for the watt for the 12v in my PSU produces 500w and i'm not gonna need more than 400w?!

    Thanks alot

    The card does not and never will need 55a, no card uses that much.
  25. do you mean the single card or in crossfire?
  26. kaspro said:
    do you mean the single card or in crossfire?

    Have a read of this article it may clear things up for you as to how much power cards do or don't use.
  27. Thanks alot, i think i'll go for crossfire for my 5770, i even got on my box
    (ATI Crossfire Certified, SLI Certified)....and i even found on ati website that they require 600w for the 5830 and 5850 crossfire!!!!!

    Anyway thanks for everyone who helped.
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