Corsair 750w loud?

[Amrry]

Hi, just a quick question about the Corsair 750w PSU. I've recently got one of these and two HD4870s in Crossfire. I use them in an antec 900 case.
Thing is that the PSU during load gets really loud, it did not do that with only one 4870 (tried that first) but when I added a 2nd it got much louder and are much worse than the two graphics cards (with the fans at a reasonable speed).

So my question is; could the problem be because of heat? Since I have the antec 900, the PSU and the 2nd card are pretty close to eachother so perhaps there's more heat getting stuck there, which causes the fan to speed up.
Or could it be because the load is much heavier on the PSU with two graphics cards than one and therefor it goes warmer -> higher speed on fan.

I was thinking about changing to another case that perhaps has the PSU a bit more isolated (like P182) from the rest of the components so then perhaps it wouldn't have to speed up as much? That is only if it's a heat issue because of the 2nd Graphics card being too close to the PSU.
If it's because the PSU have to work harder than before due to now having an extra GPU then I guess it wouldn't make a difference to switch case.

 

[WR2]

I think an issue with heat would be the first thing to look at. Possibly the flow of cool air into the PSU is blocked. Or its taking air heated by the 4870 into the PSU casing triggering a higher fan speed.
Have you tested with the case door open? What were the results of that?
You could move one of the case fans into the side window panel and see if that improves things any by trying to give the PSU a better stream of cooler air.
Some other cases let you rotate the PSU so its drawing air from the outside of the case (from underneath) like the CM RC-690.

 

[lameness]

Are you sure its the PSU?

I have the same one and its almost silent.

I have 2 4870 arriving tonight so il let you know the xfire results too.

 

[suspect]

FYI:
the TX750 psu does have a noise issue when under heavy load... but... you can fix it.

At about 400W load the fan speeds up...there is a small clear plastic deflector inside, that covers about half of the fan area and is very close to the fan.
It causes loud noise when the fan speeds up under heavy load.
If you remove it the noise will go away and it does not affect the performance of the psu.

I read this in a review of the TX750, if you google it you will get the low down.

ps I have this psu but have not had this issue as I only have 1 x 3870 and I have not removed the deflector

 

[Aurora18]

have you checked to see if the screws are tightened if so you could try some noise dampeners

 

[Gamer_Josh]

I had this same power supply in my Antec 900 case with two 8800 Ultras. But I upgraded to the Corsair HX1000W and sold the TX750 to my friend. I, nor he, has had any problems with it being loud. I don't have this problem with the HX1000W either. Just special circumstances I guess. Anyway, I'd try what 'suspect' said.