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Crossfire or SLI PSU?

Hpw big does my PSU have to be if I plan on doing an SLI or Xfire configuration for this year's GPUs? Around 750 watts? And is Thermaltake a good brand?
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  1. I go with Corsair. A 750W COrsair PSU can actually deliver 900W. What processor & graphics card do you plan on having?
  2. Currently using the XFX XXX series (750 watt). Very nice 80+ silver rated PSU with alot of modules, would reccomend this to anyone, they also do an 850 watt version which would easily allow sli/xfire.
  3. A 750W psu can't deliver 900W, but it is big enough for most SLI/Crossfire configurations. You do want to make sure its a quality psu, so that it will not kill your graphics cards.
  4. I have the XFX 750W XXX series.
    Simple put: awesome PSU
  5. totalknowledge said:
    A 750W psu can't deliver 900W

    A Corsair HX 750W can. Here:
    http://www.overclock3d.net/reviews/power_supply/corsair_hx750w_750w_atx_psu/3
    There are other reviews which will say basically the same. Here is the best:
    http://www.hardwaresecrets.com/article/Corsair-HX750W-Power-Supply-Review/775/8
  6. Peak =/= sustained load.
  7. Peak wattage only needs to be sustained for 17 seconds.

    Continuous wattage is as its name implies.

    The Hardware Secrets maximum power draw test is not a peak wattage measurement, it's continuous.
  8. totalknowledge said:
    Peak =/= sustained load.

    Let me quote from the review itself:

    The problem is that you made a generalized statement without checking & now you twist out of it.
  9. randomkid said:
    Let me quote from the review itself:
    http://img855.imageshack.us/img855/3255/corsair750w.png
    The problem is that you made a generalized statement without checking & now you twist out of it.


    Peak =/= sustained load.

    eta: all good psu's can go above their maximum rating. That's what peak is. If you run a psu above its max rating for long periods of time you are in for a world of hurt. Did you not read the part about they pushed it to the point it was about to shut down?

    http://www.antec.com/Believe_it/Events/us/Continuous_Power/
    http://www.jonnyguru.com/forums/showthread.php?t=3987
    http://www.jonnyguru.com/modules.php?name=NDFAQs&op=FAQ_Question&ndfaq_id=5
  10. freshbuilder said:
    Hpw big does my PSU have to be if I plan on doing an SLI or Xfire configuration for this year's GPUs? Around 750 watts? And is Thermaltake a good brand?

    If you plan on buying a Thermaltake psu you have to move up the line-up to get a good unit.
    TR2 RX is junk!
    The higher up series are expensive when compared to very good units from Corsair TXV2 and XFX which are very affordable.
  11. totalknowledge said:
    Peak =/= sustained load.

    eta: all good psu's can go above their maximum rating. That's what peak is. If you run a psu above its max rating for long periods of time you are in for a world of hurt. Did you not read the part about they pushed it to the point it was about to shut down?

    http://www.antec.com/Believe_it/Events/us/Continuous_Power/
    http://www.jonnyguru.com/forums/showthread.php?t=3987
    http://www.jonnyguru.com/modules.php?name=NDFAQs&op=FAQ_Question&ndfaq_id=5

    All the links you posted are irrelevant. You generalized "A 750W psu can't deliver 900W" & I disputed that with a link which states exactly the opposite.
    Now you generalize again with your statement" "If you run a psu above its max rating for long periods of time you are in for a world of hurt." Did you not read the part of the review that say "Corsair could have labeled this unit as a 900W power supply?" So this particular unit can be loaded with 900W & it will perform within specs.
    My advise to you? Never ever generalize.
  12. And it can't deliver a continuous 900W load. You implied in your post that it could be used as a higher watt psu, and it can not. It has a peak rating in excess of its max rating, that is all.

    From the review that you posted:

    - Has a sustainable peak output of 887w when running at 50°C!

    Overclock3d is not Corsair. Corsair set the rating at 750 for a reason. If it could be used as a 900W psu then that is what they would have rated it for.

    http://compreviews.about.com/od/cases/a/PSUWattage.htm

    One of the things that makes companies like Coolmax a bad company, is not the fact that it sells crappy psu's but rather that it sells decent psu's labeled above what should be their max load. They are banking on the fact that their purchasers won't really need all the power that they are advertising. When people do use that much power, they have component damage, and psu failures. Several of Coolmax's units are made by CWT the very same manufacture that makes the HX750. The difference is that Corsair has labeled the unit correctly and Coolmax has not.
  13. totalknowledge said:
    And it can't deliver a continuous 900W load. You implied in your post that it could be used as a higher watt psu, and it can not. It has a peak rating in excess of its max rating, that is all.

    From the review that you posted:

    - Has a sustainable peak output of 887w when running at 50°C!

    Overclock3d is not Corsair. Corsair set the rating at 750 for a reason. If it could be used as a 900W psu then that is what they would have rated it for.

    50°C is torture test. It is still rated at 913W at room temperature. But even if it is just 887W at 50°C, Overclock3D stated:
    "Bumping up the ambient temperature to a toasty 50°C and re-running the room temperature results, hardy anything at all changed. In fact, aside from the odd +/-0.2v fluctuation on a couple of the rails and a few dips in efficiency, the only real thing worth talking about is the MAX load test which topped out at 887w - 26w lower than in the room temperature tests. This is by no means anything to get upset about as the HX750w is still operating at 137w above its rated capacity, and with 88% efficiency too."

    Hardware Secrets clearly stated that reason why Corsair did not label it 900W even if they could. It's because they don't want it to fall below "Gold". If Corsair wanted to, they could sell this 750W as a 900W 80plus power supply which proves my statement that "A 750W COrsair PSU can actually deliver 900W" & I might add at 80plus efficiency.

    Edited for calm after moderator comment. :)
  14. Ok. Calm down.
  15. I use an antec hcg 620w.
  16. well then let me phrase it this way.

    All quality built units can deliver more than their stated rating, but you don't want to base your psu calculations on there peak load capacity.
  17. okay I'm actually more confused now than ever.
  18. freshbuilder said:
    okay I'm actually more confused now than ever.


    A quality 750 w psu should be fine for most dual sli setups. Did you have a specific card in mind?
  19. freshbuilder said:
    okay I'm actually more confused now than ever.

    If you're planning on running two 300 Watt graphics cards (like the Radeon HD 7990 is rumored to be) in 2-way SLI or CrossFireX mode then a minimum of a 900 Watt or greater power supply that has a combined +12 Volt continuous current rating of 65 Amps or greater and that has at least four PCI Express supplementary power connectors would be recommended.

    Any overclocking of the CPU and/or GPUs would require more than the minimum recommended above.
  20. I don't plan on dual running two 7990s I have a huge budget but not that high. For now I plan on getting the 560 ti then switch to the Nvidia 6 or 7 series (dont know what to say cause of rumors) then using SLI for the card that has the same price point as the 560. So far I'm considering the Corsair 850w AX850 Professional Series 80 plus gold series or the Corsair TX950w.
  21. Also considering Corsair HX1050 — 80 PLUS
  22. freshbuilder said:
    Also considering Corsair HX1050 — 80 PLUS

    If you are considering crossfire of 560 ti, then HX1050 is overkill. Even the Corsair 850W (HX or AX Model) is more than enough.
  23. will a Corsair GS 800 do? I want a bit of overkill just to be sure since I'm a bit paranoid. BTW I might upgrade to a 7970 or 680 dual GPU by the end of the year the 560 might be a temporary setup, might not even sli it anymore.
  24. Buy one of these instead you wont regret it, and it will leave you with plenty of headroom

    http://xfxforce.com/en-us/Products/Power-Supply/XFX/Pro-Series/ProSeries-850W-PSU/850W-XXX-Edition-Semi-Modular-Silver.aspx



  25. not available where I'm from unfortunately XD
  26. sorry it is available where I am, I'm thinking of getting you're recommendation if I don't get any other recommendations in the next 24 hours. Hope this really is a good buy thanks for the suggestion man
  27. again available but out of stock! T_T too bad xfx
  28. Question, I've been digging around and it seems that the NZXT Hale82 850w is actually a rebadged Seasonic M12II Bronze Series at least during this review from hardware secrets http://www.hardwaresecrets.com/article/NZXT-HALE82-850-W-Power-Supply-Review/1439/11. I was just wondering if it would be safe to assume that all the production units are just rebadged Seasonics?
  29. freshbuilder said:
    Question, I've been digging around and it seems that the NZXT Hale82 850w is actually a rebadged Seasonic M12II Bronze Series at least during this review from hardware secrets http://www.hardwaresecrets.com/article/NZXT-HALE82-850-W-Power-Supply-Review/1439/11. I was just wondering if it would be safe to assume that all the production units are just rebadged Seasonics?

    Also read the following review on that PSU:

    http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=274

    The test results between different review sites seems to indicate that there is a quality inconsistency.

    Only the three NZXT Hale82 models are made by Seasonic.

    The remainder of their power supplies in the Performance Power Series and Hale90 Series are made by Super Flower.
  30. why does getting a psu have to be a hassle? whenever I get a good recommendations its out of effin stock. Again a PSU with some headroom for an SLI build probably two 580s. BTW among the Corsair series the whole TX, AX, HX thing, which one is probably good enough?
  31. freshbuilder said:
    why does getting a psu have to be a hassle? whenever I get a good recommendations its out of effin stock. Again a PSU with some headroom for an SLI build probably two 580s. BTW among the Corsair series the whole TX, AX, HX thing, which one is probably good enough?

    I would rank the HX850W as having the best electrical performance followed by the TX850 V2 and AX850.
  32. anyone has any thoughts on thermaltake as a good psu? I've been recently looking at the thermaltake and according to Jonny http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story4&reid=45 its a good one.
  33. Best answer
    freshbuilder said:
    anyone has any thoughts on thermaltake as a good psu? I've been recently looking at the thermaltake and according to Jonny http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story4&reid=45 its a good one.

    The Thermaltake Toughpower, Toughpower QFan, Toughpower XT, Toughpower Grand, Toughpower XT Gold and Toughpower XT Platinum are the only Thermaltake series worthy of consideration. What I would watch out for is the cable lengths. Make sure that the output cables for the motherboard power and CPU power are long enough to reach the motherboard power connectors without having to use extension cables.

    The Thermaltake TR2 RX, TR2, TR2 QFan, Pure Power, Lite Power and Evo Blue Series are the ones to stay away from.
  34. Quote:
    What I would watch out for is the cable lengths. Make sure that the output cables for the motherboard power and CPU power are long enough to reach the motherboard power connectors without having to use extension cables.


    Would I only know this if I check it on the spot? My case is a NZXT phantom and my board is an Asrock extreme 7 gen 3 if that helps.
  35. totalknowledge said:
    well then let me phrase it this way.

    All quality built units can deliver more than their stated rating, but you don't want to base your psu calculations on there peak load capacity.

    well said and concise .. perhaps should have opened with that :D
  36. there is a power supply calculater out there . cant find it at the moment . I'm sure one of the more capable peeps here will post it , but yah a little headroom will provide a lot of peace of mind as well as room for upgrades in the future
  37. rufus_22 said:
    there is a power supply calculater out there . cant find it at the moment . I'm sure one of the more capable peeps here will post it , but yah a little headroom will provide a lot of peace of mind as well as room for upgrades in the future


    which is why i really want a good psu.
  38. Best answer selected by Freshbuilder.
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