Corsair 650HX for 2 5870s CF?

Hi guys, my friend currently has a corsair 650HX powering his rig as follow:
amd 955BE Oced to 3.8Ghz
Corsair Dominator 4 x 2GB DDR3 1600
XFX 5870
WD caviar black 1TB
He's intending to get another 5870 for CF, but he's wondering if the PSU may cope with the entire system.
I've look at ATI recommendation and it said 600W should be fine, however I'm not really sure as 650 and 600 are too close, so we decided to put the question here for further advice. :)
Appreciate all suggestions :love:
16 answers Last reply Best Answer
More about corsair 650hx 5870s
    A 650 would be cutting it very close, that doesnt even have the processor under full load. Generally for 2 high end cards you are looking at something like the 750TX or if you want modular the TP-750 from antec or HX750.
  2. Best answer
    Here are the ATI official power requirements for the ATI Radeon HD 5850 and HD 5870 video cards.

    ATI Radeon™ HD5850 System Requirements:

    PCI Express® based PC is required with one X16 lane graphics slot available on the motherboard

    500 Watt or greater power supply with two 75W 6-pin PCI Express® power connectors recommended

    600 Watt or greater and four 6-pin connectors for ATI CrossFireX™ technology in dual mode

    ATI Radeon™ HD5870 System Requirements:

    PCI Express® based PC is required with one X16 lane graphics slot available on the motherboard

    500 Watt or greater power supply with two 75W 6-pin PCI Express® power connectors recommended

    600 Watt or greater and four 6-pin connectors for ATI CrossFireX™ technology in dual mode

    The power supply recommendations are for an entire pc system. Figure about 40 amps on the 12 volt rail(s) for Crossfire mode.

    The Corsair HX650 has a single large 12 volt rail rated at 52 amps. It also comes with the required four, 75 watt, PCI-e, 6 pin, power connections. It can easily handle a system with two ATI Radeon HD 5870 video cards operating in Crossfire mode.

    Last January Tom's Hardware published an article about actual power consumption during gaming seessions. There have been similar reviews at other reputable web sites. The results are pretty consistent. Most people think they need more power than is actually required during hardcore gaming sessions.

    For example, while playing World of Warcraft an Intel Core i7-920 @ 3.33GHz based system with two 5870's operating in Crossfire mode drew a maximum of 430 watts at the wall outlet (mains). That's for the entire system. That's significantly lower than results for OCCT or Furmark stress testing. There isn't any game that can come close to producing the stress that OCCT and Furmark testing can.

    Here are the links to technical reviews of the 5870: [...] ,2422.html [...] eview.html [...] d5870.html
  3. Based on the power consumption figures of systems using single and dual 5850's and 5870's, a 5850 will need about 12 amps and a 5870 will need about 15 amps.

    Figuring 10 amps for an OC'd CPU takes you to 40 amps.

    Considering that Corsair PSU's are conservatively rated (you can generally pull 15% - 20% more than the rated power), you should be fine with the Corsair PSU.
  4. If I were buying / building new, I'd probably recommend an 850 watter out of Antec's SG / CP / TP series or Corsair's HX / TX (listed in order of quality). Since you have a HX already, , I'm gonna echo JL up there and say I wouldn't be too concerned about twin 58xx's at modest overclocks. If looking for serious OC's, a top end PSU and superb MoBo power regulation are important building blocks.
  5. So generally that corsair 650hx may cope well with 2 5870s, as you said.
    Then how about its durability and other components' stability?
    Does "too close"mean it also shortens the components' lifetime?
    Thanks in advance :)
  6. Corsair has a reputation for high quality power supplies. They consistently earn high marks in technical reviews. They are stable, reliable, and come with a 5 year warranty. The HX650 is a new model. Technical reviews are not yet available.
  7. yea, but does "too close"mean it also shortens the components' lifetime?
  8. All power supplies age. High quality power supplies age very well due to the use of heavy duty components. That's part of the reason they do well in technical reviews and come with a 5 year warranty. My power supply is four years old and still going strong.

    As for the "too close" comment, did you click on the link provided by hunter315? The results are for Furmark stress testing which I explained in my original post.
  9. Thanks for all, my friend must be very happy as he could finally save some bucks. :D
  10. @johnny: do you have any source that has us fill in our system specs and calculate total wattage consumed?
    We're wondering with the system above, how about we add another SSD and a WD velociraptor?
    Is the 650HX gonna explode or something? :D
  11. hehehe - It will not explode. Drives use very very little power, maybe 15 watts at start-up and less than 10 watts while in operation.

    I have several wattage calculators referenced. I have a favorite because it goes into quite a bit of detail. Unfortunately it has not been updated for newer cpu's and gpu's. Sigh!

    Here's a link to the general purpose Antec power calculator that is up to date:

    NOTE - Your motherboard has a single cpu socket. Don't change that part. Some people confuse that with cpu cores.

    Please remember that the result is a recommendation only and may not reflect actual consumption.
  12. Well, we've got roughly 524W consumed.
    So as long as it does not hit 600w then we'll be fine, right? :D
  13. Right on!

    Remember the 524 watts is a recommendation and it''s overestimated. During a gaming session the actual power consumption measured at the wall outlet (mains) will be less.
  14. wow you've just enlightened me, johnny :)
    Coz from what I 've been reading through, people always suggest a gap of 200W or more than the one that officially recommended.
    They said that gap would not stress the PSU and thus maintain for high stability, is that true?
  15. You've got the gap - You're looking at a 620 watt power supply. During a heavy duty gaming session with your Crossfire system you'll draw a maximum of a little over 400 watts. That's maximum which is not constant power consumption. Your overall gaming average will be down around 300 watts.
  16. Got it, thanks :)
    I guess my friend would not have anything more stress than gaming :D
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