Author

Topic: 6 GPU rig. -- Major problems (Read 1685 times)

newbie
Activity: 59
Merit: 0
December 23, 2013, 03:11:21 AM
#4
Yes, it always happens after I install the new ATI driver. Linux, Windows 8. SAME THING ON EACH OS.

Regarding the PSU. I disconnected the smaller PSU (maybe you couldn't see but I had a second PSU there behind the last 2 cards powering those + the molexs on that side) and just hooked up 4 GPUs and the mobo. I still get the output problem from the DVIs. It crashes every time the driver tries to initialize in Windows. I even swapped out the GPUs with 4 R9 290s I have sitting here just to see if it was the GPUs. I'm having the same issue. I get output from bios + Windows loading screen, but as soon as it hits the login screen it will freeze up or give me a black screen entirely. Sometimes it even kicks the GPU fans onto high gear for no reason. I have a Kill-a-watt on the end of the surge and it never reports more than 200watts being pulled at a time. The only time I've been able to get it stable is when I have only one GPU plugged in.

I'm gonna RMA the mobo as I'm at a loss of what else to do here. I have read that Gigabyte doesn't always play nice with ATI cards. Hopefully a nice Asus will do the trick.
legendary
Activity: 1344
Merit: 1004
December 22, 2013, 07:09:58 PM
#3
The radeon 280X uses the exact same chip as radeon 7970. It's no surprise it's detected as a 7970 sometimes.

The problem you describe is not a power issue or motherboard issue. It is an OS/driver issue.
hero member
Activity: 490
Merit: 500
December 22, 2013, 03:58:11 PM
#2
Try moving the monitor cable to all the different cards to see if you get an output after the screen goes black. It maybe outputting the display on another card.

If that don't work...

You have 3 PSU rails ((Rail1-1300W+Rail2-600W)Max Combined 1560W) and the other PSU is a 744W rail.
Overloading a power rail would cause problems like this.
Try spread the power out over more individual cables and check your not overloading a rail.

75w x 6 = 450W just on the molex alone.
6-pin+8pin = 225W per GPU x 6 = 1350W.
CPU & Mothboard = 100W at least.
Total = 1900W (82.5% of the max available)

It may be kicking in the "Protection" feature...
Quote
"Over Temperature/Current/Voltage/Power Protection, Under Voltage Protection, and Short Circuit Protection provide maximum safety to your critical system components."

If it's not the power it may be the CPU or MB not supporting 6x PCI-e properly.
newbie
Activity: 59
Merit: 0
December 22, 2013, 03:07:33 PM
#1
This is my first build. I thought I did my research here, but I guess not. Before I tell you the issue, let me tell you my setup:

Gigabyte Z87X-UD4H motherboard (3 1x PCI-e and 3 16x PCI-e lanes)
6 Sapphire ATI Radeon R9 280x GPUs
4GB G.Skillz RAM
Intel Pentium Haswell CPU
2 PSUs w/ adapter:
1600w Rosewill Hercules (4 GPUs)
750w Rosewill Capstone (2 GPUs)
Every GPU has a powered riser.

Okay, so now to the issue. First I tried BAMT. I get the loading screen and it starts showing me all the services starting until it gets to GDM, then the screen goes black and becomes unresponsive. Tried fiddling with a billion BIOS settings, one GPU only, nothing worked. Gave up on BAMT.

Moving along, I decide to try my own Fedora install. I am a huge fan of Fedora. The LiveCD boots right off the bat. Everything working good until I go to install the latest ATI driver. I install it successfully. Hooray. I reboot and when Xorg tries to initialize...Bam! Black screen.

Okay, so after much tweaking I very sorrowfully give up on Linux and fall back onto Windows 8. I install Windows 8. Everything goes great. I get into the desktop and look in device manager. All my cards are detected, but as Radeon 7970s or just general Microsoft display adapter. I go to AMD's website and install the latest ATI Radeon drivers (13.12). Screen goes black. Same deal as last time.

So I decided to leave the driver alone in Windows. It detects my cards as an ATI 7970 series. Okay... whatever. That's fine. Problem is it only detects 4 cards usually. Well, once I got it to detect 5, but the thing crashes every time i try to start cgminer. Moving on to that problem. I got cgminer up and running and I actually had 3/4 cards running at a  good hash rate (750kh/sec). Problem is that one card would hash at ~80Kh/sec. I figured I might have a bad card. So I started swapping em out and around, and seems its always the card that I have the display plugged into. Should this be happening? I can try the onboard video for my display I guess.

I am absolutely baffled here. I've been working at this for two days straight. It's like the drivers just won't initialize for more than one card. Do I need dummy plugs? 2350 watts of power is surely enough?!

On top of this, I got 4 Gigabyte Radeon R9 290s sitting here, waiting on the rest of the parts to build another 4 GPU rig. I decided to swap them out with these cards just to see if it would work. Sure enough I am getting the same damn black screen. These are all brand new cards from newegg. Should I RMA this POS?

Here is a photo of my setup:

https://i.imgur.com/yP2Mcml.jpg

Thank you for any help in advance.
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