ATI Radeon HD 7870 not powering up, is PSU to blame?

Everything is at stock speeds, not-overclocked, the system can handle as much as nVidia GeForce GTX 560 Ti
but
ATI Radeon HD7870 makes the system turn off a few seconds after the power button is pressed.


Is my Corsair CMPSU-750TX just not powerful enough, or how do I test it to see if it should be RMA'd, it is still under warranty.


P.S. If you would happen to know what a good deal is now for a more powerful PSU if I need one, please post.



_____________________
Intel i7 950 [206] BCLK x 20 = 4.12 GHz @ [1.4000] CPU Voltage & [1.35000] QPI/DRAM Uncore Voltage, Batch 3029A40
2 x 4GB Kingston HyperX T1 DDR3 1600 (PC3 12800) [DDR3-1651MHz] 9-9-9-27 @ 1.66 DRAM Bus Voltage
ASUS P6T Deluxe v.1 [LGA 1366 Intel X58] BIOS 2209
Thermalright Ultra-120 eXtreme 1366 RT with 120mm Scythe S-Flex F fan
nVidia GeForce GTX 560 Ti PNY XLR8 1GB GDDR5 822MHz Core Clock
ASUS ATI Radeon HD 5450 [used for HDMI HD sound only]
OCZ Agility 3 180GB SSD
Asus Xonar DX sound card
Antec nine hundred case, two front 120mm fans, one back 120mm Fan, one top 200mm fan
Corsair ed 750W



EDIT: I tried the ATI Radeon HD7870 at everything set to stock speeds and it was No-Go but here are the system voltages when the system is actually overclocked and successfully running nVidia GeForce GTX 560 Ti:

No way a 7870 consumes more than my 470 SLI. I'd say the card is DOA.

Have you tried the 7870 in another machine? That TX750 should handle two of them, overclocked, with that overclocked CPU and not break a sweat. The 7870 only draws something like 5W more than the 560Ti too.

The 12v looks a bit low, tho mine sits at 11.6-11.9, and the other rails sit even lower than yours. Mine needs to be replaced soon. I'd have to point my finger at the ati too, if it has no problem driving the nvidia.

So the video card itself can stop a healthy system? OK, so since the system can handle nVidia GeForce GTX 560 Ti, you're saying, if the video card disables another system, RMA the new video card, but if the video card does actually run on another system - then the Corsair is going bad and it should be replaced?

If it's not the video card, it's most likely the PSU, but I think further testing is necessary to make it a certainty. Mainly running Prime95+Furmark at the same time with your current card.

A dead GPU will cause that.
I'd say a dead GPU is causing that, the 560Ti has very similar power needs, if that was going to be an issue it'd be under load anyway.
Do you have the power connector(s) plugged in?
Is the card fully seated?
Any dust/hair/gunk in the PCIe slot?

I'd be very, very surprised if it was a PSU issue. You could run three 7870s on that PSU if you didn't OC things.


EDIT:
If you have a multimeter you can use that to check the PSU voltages. Software tools are essentially useless for it unless they've been calibrated against a multimeter.

Power connecters are plugged in. Will try different slots next.

Bobnova said:

I'd be very, very surprised if it was a PSU issue. You could run three 7870s on that PSU if you didn't OC things.

Click to expand...

Thank you Bobnova, this is exactly the kind of info I was looking for regarding power needs.

Also, just out of curiosity, what are the limitations of this PSU as far as my overclocked system below, and the new video cards on the market? Could it run two cards, or are Corsairs 850W and higher needed?


_____________________
Intel i7 950 [206] BCLK x 20 = 4.12 GHz @ [1.4000] CPU Voltage & [1.35000] QPI/DRAM Uncore Voltage, Batch 3029A40
2 x 4GB Kingston HyperX T1 DDR3 1600 (PC3 12800) [DDR3-1651MHz] 9-9-9-27 @ 1.66 DRAM Bus Voltage
ASUS P6T Deluxe v.1 [LGA 1366 Intel X58] BIOS 2209
Thermalright Ultra-120 eXtreme 1366 RT with 120mm Scythe S-Flex F fan
nVidia GeForce GTX 560 Ti PNY XLR8 1GB GDDR5 822MHz Core Clock
ASUS ATI Radeon HD 5450 [used for HDMI HD sound only]
OCZ Agility 3 180GB SSD
Asus Xonar DX sound card
Antec nine hundred case, two front 120mm fans, one back 120mm Fan, one top 200mm fan
Corsair CMPSU-750TX 750W

That 750 should be able to run two of anything, even with some OCing.
GTX480's OC'd might not be a great idea, nor would 590s or 6990s or 690s.

Thanks again, 750W Corsair CMPSU-750TX appears to be a-OK:

Yup that looks good.