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can my PSU handle this?

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calaveraOC

Registered
Joined
Jun 15, 2007
Location
Socal, USA
so this is my setup so far:

Q6600(G0)@3.0Ghz
1x 5850
1x SSD (Intel X-25M G2)
6x HDD's (WD black's)
1x DVD (never use it :p)
~7 USB devices (including mouse,keyboard)

PSU : Corsair HX620

So far its no problem but what if I want to add another 5850 and xfire?
can my psu handle it?
I tried the online calculator and it comes out to 635W under load.
 
According to a PSU calculator, even with crossfire you're only looking at 450W. Since I have faith that your Corsair unit will actually deliver 620W, you should be good to go.
 
That's pushing it a bit close for comfort. On full load a pair of 5850's in CF draws around 550w(Total System Draw).

Be safe, protect your gear and have some peace of mind and get a bigger PSU.
 
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so this is my setup so far:

Q6600(G0)@3.0Ghz
1x 5850
1x SSD (Intel X-25M G2)
6x HDD's (WD black's)
1x DVD (never use it :p)
~7 USB devices (including mouse,keyboard)

PSU : Corsair HX620

So far its no problem but what if I want to add another 5850 and xfire?
can my psu handle it?
I tried the online calculator and it comes out to 635W under load.

Cal,

You're fine with a single 5850 (~150w full load), not even close, they use a little less power than a 4870. It will run crossfire with that card but it gets a little "sticky" only because you're running the power supply at a high percentage of capacity. So if and when you crossfire, I'd get something a little bigger.

Reference: http://www.guru3d.com/article/radeon-hd-5850-review-crossfire/2

Personally I'm not a fan of SLI/Crossfire, the gain per dollar output just isn't worth it (to me) for a high-end vid card unless you're a benchmarking person.

One of our guys (Thideras) runs a server with 21 hard drives HX620 and single graphics card without a problem so you can take that as a good reference.
 
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really? I dont know who to believe now :p

Cal,

You're fine with a single 5850 (~150w full load), not even close, they use a little less power than a 4870. It will run crossfire with that card but it gets a little "sticky" only because you're running the power supply at a high percentage of capacity. So if and when you crossfire, I'd get something a little bigger.

Reference: http://www.guru3d.com/article/radeon-hd-5850-review-crossfire/2

Personally I'm not a fan of SLI/Crossfire, the gain per dollar output just isn't worth it (to me) for a high-end vid card unless you're a benchmarking person.

One of our guys (Thideras) runs a server with 21 hard drives HX620 and single graphics card without a problem so you can take that as a good reference.
+1

That 620HX is one of hte best in its class. Even without that. One certainly wouldnt need a 850W or especially a 1kw PSU... seriously people!!! I also believe it would handle a quad and 5850's in Crossfire as well. And I agree with RT in that it would run a bit high to its rated capacity. So you may hear the fan spin up. But I believe it would handle it. Hell, it could handle two 7900gtx's/X1950xt's and a dual so I dont see why it wouldnt run two of something that uses less power. I could only imagine that under 100% stress on CPU and GPU that system will only draw 500W or so. THe HDD are nothing except on spinup. As far as the USB is concerned, thats not on the 12v rail, its on the 5vSB I believe. The 620HX has 3A which should handle 10-12 USB peripherals so you are good there as well. RT please correct me if I am mistaking.
 
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+1

That 620HX is one of hte best in its class. Even without that. One certainly wouldnt need a 850W or especially a 1kw PSU... seriously people!!! I also believe it would handle a quad and 5850's in Crossfire as well. And I agree with RT in that it would run a bit high to its rated capacity. So you may hear the fan spin up. But I believe it would handle it. Hell, it could handle two 7900gtx's/X1950xt's and a dual so I dont see why it wouldnt run two of something that uses less power. I could only imagine that under 100% stress on CPU and GPU that system will only draw 500W or so. THe HDD are nothing except on spinup. As far as the USB is concerned, thats not on the 12v rail, its on the 5vSB I believe. The 620HX has 3A which should handle 10-12 USB peripherals so you are good there as well. RT please correct me if I am mistaking.

ED,

I'm not sure of the required output of USB devices, I use so few of them (wireless where I can) that I have never had the need to find out. It's not much per USB item.

Some but not all of the new high-end video cards are giving much more with lower power requirements today. The engineering is progressing along with the quality so in many instances SLI/Crossfire power requirements have not gone up. A quality power supply will also save you from yourself and that HX620 certainly is a good one.

Do you remember the long thread here by mcoleg?:

http://www.overclockers.com/forums/showthread.php?t=511180

Which proves the point about power requirements. I wouldn't do that in a daily "real world" setup but you could and it's still a valid "test" thread.
 
I read that USB thing somewhere. If I have time I can dig up the link. I recall like 7-9 USB perihperals at 2.5A on 5vSB and 10-12 or so with 3A on 5vSB...

That thread was before my time but is certainly valid here. People have been scared into thinking they need much more than they actually do. I see posts from people here (everywhere) like that all the time. Thing is, it cant HURT to have more, but I work very hard for my money and if I can save $30 on a lesser output PSU, or in this case $100 with people crazily suggesting a 1kw monster, I will certainly do it.

You and I have the same feeling on what percentage to run PSU's at (60-70%). that allows for quiet opertion in its efficiency sweet spot as well as allowing PLENTY of headroom for transient response. With a quality PSU like this, I personally wouldnt hesitate to run it at 80% output constantly. But in this specific case, even with 2 GPUs, that CPU AND GPU's will have to be running at 100% (which isnt remotely accurate when gaming) to achieve that number (~500W).
 
The corsair 620hx will be good enough. A lot of people over estimate the amount of power they need for their systems when a good solid reliable psu will do the trick..

I am guilty of this as well =P.
 
The corsair 620hx will be good enough. A lot of people over estimate the amount of power they need for their systems when a good solid reliable psu will do the trick..

I am guilty of this as well =P.

At one time I was just as guilty. Worried about the same things unnecessarily until you speak with and listen to our own OW or the guys at [H]ardop.com :shrug:
 
thanx for the replies guys. very helpful and informative

out of curiosity though, what happens if you do have an underpowered PSU, will the system just shutdown? crash an application...or cause PSU meltdown? :-/
 
heat output would be higher on the psu exhaust. you will notice voltages dropping under load. if you overload it, it might shutdown if it has any over current protection. ripple voltages might make your cpu unstable.vthe durability would go down with heat. every 10°c halves the life of the components. efficiency should go down with more heat = more power from the wall + more heat.

what about 5970's or if they even can be crossfired and a i7? wouldn't that warrant a 1kw psu for the 70% load and the power for some water cooling or you need something to cool that stuff down. (not even including motherboard into the equation)
 
If he's fine with that setup and a 620w psu, I should be alright with a q9550 at just over 3.2ghz and a 5850 on a 600w OCZ right? Just got one this afternoon and when the cards under load the PSU is starting to whine :/
 
If he's fine with that setup and a 620w psu, I should be alright with a q9550 at just over 3.2ghz and a 5850 on a 600w OCZ right? Just got one this afternoon and when the cards under load the PSU is starting to whine :/

Easily

Ive got an OCed I7 and a GTX260 running off a Corsair 520. And a Q6600 with an 8800GT running off an Antec Earthwats 450 and never had issues with either.

Even have an E6400 and a 9800GT on an Earthwats 380W

All machines are running at 100% usage 24/7
 
Easily

Ive got an OCed I7 and a GTX260 running off a Corsair 520. And a Q6600 with an 8800GT running off an Antec Earthwats 450 and never had issues with either.

Even have an E6400 and a 9800GT on an Earthwats 380W

All machines are running at 100% usage 24/7

Thanks. Voltages on it are stable and checked that online PSU calculator (said I could have gotten away with a PSU that could supply 300w), just wanted to double check about the whine, but I guess that's just normal then.
 
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