Can Corsair HX620 Take On 2 GTX275?

As title says..I was just thinking about to add another GTX275 in near future
but when I looked at my HX620 lol, something tells me I need a better PSU
Since buying another HX750/850 will cost me another 200~300USD
So I'm thinking of using 4 molex pin and convert into 2 PCI-E power pin
Since HX620 has 2 PCI-E power pin and combine with the another 2 PCI-E power pin and that makes 4 PCI-E which is required for 2 GTX 275, and I gonna spread it like this, one GTX275 will get one direct from the PSU and one from 2 molex pin.

So...my specs are
i7 920@3.7GHz@1.275v
3x1GB Kingston DDR3-1600
Asus P6T
1 WD 640GB HDD
1 DVD-RW

And I did some research from wiki, it says single GTX275 TDP is 219W and 2 of them makes 438W, but my PSU is rated at 620W
Adding my i7 takes up 130W and that makes 568W..
Just thinking is it enough for 2 GTX275 ?

Thanks in advance
15 answers Last reply
More about corsair hx620 gtx275
  1. I would personally go to a 750w or better with four PCIe connectors. I have had some bad experiences using those molex converters, and actually fried a PSU and GeForce 9800GTX.
  2. your PSU probably will handle it since corsair makes PSU's that can output a lot more than they say, though i would get a corsair 750TX
  3. I see...
    Thanks for the advice
  4. TDP is not power drawn.

    I know they have not updated this for the 275, but 2xGTX280 draw 345w at peak
    http://archive.atomicmpc.com.au/forums.asp?s=2&c=7&t=9354

    And remember, its not about total wattage... but the amps available on the 12v rail
  5. If you look at Anandtech's review (link below), they have a total system power draw chart with SLI GTX280's needing 490 watts and SLI GTX260's needing almost 400 watts. Remember, that a complete system with a Core i7 965. Your GTX275's will fall somewhere between those two. Since Corsair makes a high quality unit, I'd say you are fine.
    http://www.anandtech.com/video/showdoc.aspx?i=3517&p=13

    You may need to buy some molex -> 6pin PCI adapters since I'm not sure the HX620 has enough.
  6. Yea, HX620 comes with 10 molex pin, and XFX provide 2 molex pin converter even they got a paper inside say it is no good to do so LOL

    My HX620 has 3 +12v rails and around 54A max
    And which is the molex rating? Is it the +5v?
    If the +5v the available Amps I guess is 30A

    Is it enough ?
  7. xyzionz said:


    My HX620 has 3 +12v rails and around 54A max

    3 "virtual " 12v rails with no OCP, effectively making it a single rail unit with a max 12v output of up to 50 amps, of course this depends on the 3.3 and 5v load.
    I'd upgrade just to have the proper connector's.
  8. This article from X-bit has a non overclocked i7 920, 3x1 GB DDR3 RAM and a GTX295 (close to the same usage as 2- 275 in SLI) It rates at 502w at full load, but it is a non overclocked CPU.
    http://www.xbitlabs.com/articles/coolers/display/system-wattage_8.html#sect0

    It will work, but you'd be better off with more power.
  9. I think you should get 750W PSU to be safe. You don't want to ruin the experience because your PSU can't deliver enough power.
  10. Yea, I guess so...time to put the PSU back into box and sell it lol

    Thanks guys
  11. Go to Corsair http://www.corsair.com/
    Use the PSU Calculator.
    Your set-up with 2 GTX 275 = 1000watt
  12. corsair just wants to take your money. i'd rather go with hx750. if you're that worried, go with 850 just to leave some room. That's what i'm doing with my new i7 system.

    using HX850 for I7 920 and get SLI GTX285 but i'm pretty certain that HX750 should do as well.
  13. knotknut said:
    Go to Corsair http://www.corsair.com/
    Use the PSU Calculator.
    Your set-up with 2 GTX 275 = 1000watt


    LOL!!!!


    NO.
  14. +1 skittle.

    no way 2 gtx 275s need 1000 watts... not even close.
  15. I would tell you to get something with more Rails with a Higher Amp. And He should get a 850w or higher PSU. Im using a 1000w and when I get my new PC i'll need a 1200W or higher for my setup. Its just about better now adays just to get the higher one with a higher AMP limit. Oh if you must get one with that come with 4 Rails for GPU's Thats what mine is setup for. I know your going to be using 2 GPUs but dont use the molex setup it takes that whole rail its on. You cant put anything on that rail but the GPU and if your using Molex put the converter as close to the PSU as you can.
Ask a new question

Read More

Graphics Cards Power Corsair PCI Express Graphics