Is my PSU good enough for my 4890?

[yorro]

I currently using my ATI 4890 with a HEC WIN+ Power 550W 28A on 12V. I have calculated that my total system only takes 380W, so there is a lot of room.

I read in a forum that 28 amps on 4890 is too low. What is the minimum and recommended amps on the +12V for 4890?

Currently:
■Suffering minor pauses while playing Crysis 1650x1050 ALL HIGH 2XAA 30-45FPS
■Suffering from minor pauses whenever I play COD4:MW2 on 1650x1050 ALL MAXXED/EYECANDY 4XAA with 60FPS. About 0 to 2 hiccups/pauses every mission.
■Suffering from heavy pauses on COD4:MW2 same settings as before with 60FPS while recording on FRAPS, FRAPS is set to half screen size.

Pauses/Hiccups were significantly reduced or totally neutralized when I disabled two high definition audio devices(Digital Audio S/PDIF).

SOMETIMES +12V has a minimum of 11.88V and a maximum of 12.10V


I am worried about 28A being to low.

 

[hunter315]

28A on the 12V rail is horribly low for something that claims to be a 550W PSU, the corsair 400CX offers 30A and you wouldnt run a 4890 off of that would you?

That PSU calculator calculates the total power draw of the system, remember that about 80% of the power a modern system uses is from the 12V rail, and yours can only provide up to 336W from its 12V rail so you certainly dont have enough power, a good 550W unit like the corsair 550VX or Antec TP-550 would be plenty. Try to get a PSU from Antec, Corsair, PC Power & Cooling, Seasonic, or OCZ, they all make high quality PSUs and are conservatively rated.

 

[bystander]

I'm confused by this, as I have an Antec 650W PSU and it has two 12V rails at 22A and one 12V at 25A.

It runs a 5870 great, but keep in mind, it uses two of them to power it.

Are you saying that it's horrible under amped?

 

[hunter315]

No, the Hec has a single rail and has a total output amperage of 28A on its 12V rail, your Antec will provide 45A combined if its the EA650, its the combined current available not the current available on a single rail that matters the most as most designs share a single 12V source so the multiple rails are really just a single rail anyway.

 

[bystander]

I feel better now. Thanks. I was wondering if that was the case.

 

[bystander]

I have another questions. How did you find out how many amps this has? No where on the box does it say 45A.

Or did you mis add the amps on the 3 rails and it should have read 69 (22+22+25)?

It is the Antec EA650 Earthwatts PSU, and no where on the box, manual or online do I get that info.

 

[yorro]

I am new with this PSU thing, do I need to add the amps of +12V1 and +12V2??

 

[hunter315]

Sticker on the side of the PSU, newegg always has a picture of it.
http://www.newegg.com/Product/ImageGallery.aspx?CurImage=17-371-015-S05&SCList=17-371-015-S01%2c17-371-015-S02%2c17-371-015-S03%2c17-371-015-S04%2c17-371-015-S05%2c17-371-015-S06%2c17-371-015-S07%2c17-371-015-S08%2c17-371-015-S09&S7ImageFlag=2&Item=N82E16817371015&Depa=0&WaterMark=1&Description=Antec%20EarthWatts%20EA650%20650W%20Continuous%20Power%20ATX12V%20Ver.2.2%20%2f%20EPS12V%20version%202.91%20SLI%20Certified%20CrossFire%20Ready%2080%20PLUS%20Certified%20%20Active%20PFC%20%22compatible%20with%20Core%20i7%2fCore%20i5%22%20Power%20Supply

Underneath the chart on the left, the second line of text tells you that the combined wattage of them is 540W. Current = Power/Voltage so 540W/12V=45A combined.

 

[hunter315]

OH! that makes it a lot better, you have 40A of power available on your 12V rails in that case which is much much better. I noticed your edit, do you still have pauses and stuttering? Your PSU should be sufficient for the 4890 so it may be software conflicts.

 

[yorro]

OH! that makes it a lot better, you have 40A of power available on your 12V rails in that case which is much much better. I noticed your edit, do you still have pauses and stuttering? Your PSU should be sufficient for the 4890 so it may be software conflicts.

How are you able did you able to add the 12Vrail? 28+20=40?

The stuttering/pauses/hiccups were significantly reduced whenever I disabled two high definition audio devices(Digital Audio S/PDIF). Stuttering still exists but the gameplay is smooth(Over 60FPS).

Heavy stuttering exists whenever I record COD4:MW2 using FRAPS, even though FPS is constant at 30. Fraps is set to 60FPS/Half-Screen

40A is good.

So I don't have to worry about future problems and even current performance degrade on my 4890 with this PSU?

BTW My System Spec is.
Q9550 @ 2.8GHz
2GB RAM DDR2 @ 800MHz
ATI 4890 - GPU @ 850MHz - Driver Version: 8.681.0.0
Hec Win+ Power 550W

 

[bystander]

He's taking the 480W listed for the combined total of your 2 rails and dividing it by 12V. 480W divided by 12V = 40Amps.

He's helped me a lot there.

 

[yorro]

So I don't have to worry about future problems and performance degrade on my 4890 with this PSU?

My PSU is not related to any stuttering?

I am planning to buy two more 2GB of RAM to reduce stutter IF my PSU can pull through.

 

[hunter315]

It provides plenty for a 4890 or any other single GPU so it is likely not the source of your problems. The 2GB of ram would help performance and possibly eliminate your stutter as it seems unlikely that the PSU is at fault.