PC shutdown 1xR9 280x 800w psu

[Thelod]

Rig:
MB: Asus M4N72-E (bought in 2009)
GPU: Gigabyte R9 280x Rev 1.0
CPU: AMD Phenom x4 955 3,2Ghz (bought in 2009)
Ram: 2x4gb ddr2 (bought in 2009)
PSU: Corsair Gaming Series GS800 2013 Edition 800W 80 PLUS Bronze

Cgminer settings:
"gpu-threads" : "2",
"gpu-engine" : "1031-1031",
"gpu-memclock" : "1500",
"gpu-powertune" : "8",
"intensity" : "13",
"thread-concurrency" : "11200"

I was running a 500w OCZ 80plus Bronze for about a month, but a week ago my system started crashing(no bluescreen) 1 minute after starting cgminer.
Temps where at GPU:77°C/CPU:50°C during the crash so i thought it could only be the PSU.
Now i got a 800w PSU and i can mine just fine if i don't touch the PC at all during the mining process.
However as soon as i use a web browser for a few minutes the system crashes yet again without a bluescreen. Before my 500w PSU stopped working i could mine and browse the web without any problems.
Unfortunately i can't read the VRM temps on my Gigabyte R9 280x with GPU-Z but i don't think this is the cause of these crashes.
Could it be the Motherboard? What else could cause an instant shutdown?

Any help is appreciated.

[Blobby]

Not that it helps, but I've just set up my first ever card (R9 280X) using corsair AX760 PSU, and have the same shut down issue.

I found that if I remove the Intensity value (-i) from my cgminer cmd file, it doesn't shut down.

However the hash rate is shockingly low at 16khs, with and without the -i value specified.

I'm a noob at this and just put it down to me not doing something, so immensely interested in this thread.

Regards

Rob

[Wipeout2097]

77ºC is too high. The fan should always run at high speed.

"gpu-fan" : "70-90",

Post screenshots of GPU-z while mining, both tabs and also of speedfan.

Are you undervolting the card with VBE7? Since you can't read the VRM temperature, I hope you are.

That said, there are defective Corsair PSUs in the market

[Thelod]

77ºC is too high. The fan should always run at high speed.

"gpu-fan" : "70-90",

Post screenshots of GPU-z while mining, both tabs and also of speedfan.

Are you undervolting the card with VBE7? Since you can't read the VRM temperature, I hope you are.

That said, there are defective Corsair PSUs in the market

My card was running with 77°C while fans where at 100%.
I undervolted it using VBE7 to 1,094 and they run at 71°C max now with fans somewhere between 70-85%.
Haven't seen a crash since then but 77°C on the GPU shouldn't cause a shutdown so i can't really say which component might be faulty...

http://imgur.com/BWcy7yK,lcmRu0j
http://imgur.com/BWcy7yK,lcmRu0j#1

Not that it helps, but I've just set up my first ever card (R9 280X) using corsair AX760 PSU, and have the same shut down issue.

I found that if I remove the Intensity value (-i) from my cgminer cmd file, it doesn't shut down.

However the hash rate is shockingly low at 16khs, with and without the -i value specified.

I'm a noob at this and just put it down to me not doing something, so immensely interested in this thread.

Regards

Rob

I sometimes get 10-20kh/s i can fix that by launching a game in fullscreen mode and close it.
Doesn't always work right away but at the second try it works most of the time.

[Wipeout2097]

Take a look at the voltages expected and effective:
http://imgur.com/BWcy7yK,lcmRu0j#1


+3.3V : 1.14V  
+12V: 9.98V
-12V: -1.5V
-5V: 1.58V
 

Could be that speedfan wasn't really successful at detecting the chipset or gets crap from the SMBus, but if those readings are correct, there are serious issues on the motherboard or PSU.