Added Sapphire OC 7870 for Crossfire - BSOD

jeffreylec

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May 30, 2014
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Update: Bought a new PSU (Corsair CX750M, I know it wasn't what was recommended, but it should have just worked for the meantime). Enable Crossfire and loaded up a game, BSOD. Tried to run FurMark, BSOD. Same exceptions, same BSOD. I cannot figure out this problem.

Update 2: So I tried GPUs in both slots singularly to make sure they work - they do. Kept on getting the same problem in fullscreen...Problem was, my monitor is 144hz and Crossfire does not like anything about 120hz really, so I reverted my settings back to 120hz and viola! My games work! Thanks for the help previously! I might sell the card and return the PSU, because I really enjoy the 144hz.

TL;DR below.

Hey guys! I have been looking around the forum and I cannot seem to find much information on this...

To start off. I uninstalled both drivers from each graphics card, updated to the new 14.3 Catalyst Control Center, installed 14.2 on both GPUs.

My computer runs totally fine when I am using it normally, but when I load up a game (any game) it will crash (BSOD).

The dump file: atikmdag.sys and ntoskrnl.exe (SYSTEM_SERVICE_EXCEPTION)

Now, when I disable Crossfire via Control Catalyst, my game works perfectly, no crashing. So this leads me to believe it is my power supply that is causing the problem.

Now, the CX500 only has 2 (6 pin) PCI-e cables and the graphics card comes with adapters for (4 pin) Molex. The fans on the second graphics card (that is connected with the adapters) work and it reads on my computer, but I believe as soon as I start a game, it fully utilizes its power in which the computer BSODs

So my question:
(1) Is the adapters not giving the graphics card enough power? I have heard that the conversion from Molex (65W?) to PCIe (75w?) is not enough to power the card.
(2) Is the power supply, regardless of the Molex/PCIe adapters, not giving enough power to power my whole system?

TL;DR: Added new GPU, using Molex-to-PCIe adapters, computer BSOD when game launched, what is the problem?

My current setup:
MSI Z77A-G45 Military Class III
Intel i5 3570K Ivy Bridge
2x 4GB DDR3 Corsair Vengeance
2x Sapphire HD 7870 GHz Edition OC 2GB GDDR5
Corsair CX500 (Non-Mod)

I would really appreciate any feedback or help!

Thank you in advance,
Jef
 
CX PSUs are not meant to push gaming rigs.

"CX Series PC power supplies are an excellent choice for basic system builds" -Corsair.

There have been several CXs go out with a bang this week while pushing expensive hardware. Scan through the forums and you will find the posts.

Since you are running OC versions of the cards in CFX, you should get a quality 650W, like the XFX PRO or Rosewill Capstone.
They aren't terribly priced.
The only good Corsair PSUs available now are the AXi. You might find a couple TX and HX but they are getting rare.
 

jeffreylec

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May 30, 2014
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I was thinking about getting a CX750M from Best Buy today? Do you think that would be appropriate? I am going to check out a few others today as well. Thank you for your input.
 

jeffreylec

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May 30, 2014
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Well, I bought a new PSU, set up both graphics cards to PCI-e, no adapters this time. Everything is running.

Loaded up a game (CS:GO), BSOD immediately. Same exceptions.