7850 Black screen and lockup.

[StarkyA]

So I just got a brand new Gigabyte 7850 from here ( http://www.overclockers.co.uk/showproduct.php?prodid=GX-100-GI ), and I suspect I may have a bad one.

System is as follows:
2500k @ 4.2 Ghz
16 GB 1600 hyperX
Gigabyte z68x-ud3-b3
Corsair 650TX

The system was utterly stable with my old 5770, but now in almost any game that stresses the GPU (most notational sleeping dogs and far cry 3) it locks up my system after 5-10 mins playing.

Black screen with a looping sound buzz - which needs a hard reset to fix.

It's not a heat issue, temps never go above 55, doubt it is a power issue - the 650TX should be more than enough, and the system is fine with the 5770 which draws less, but not massively less. Drivers, bios and everything else is up to date.

Googling about seems this is a common fault with OC 78xx's so I tried underclocking back to stock and it becomes a lot more stable (like 1 lockup in 4 hours play).

So it seems I got a card that can't handle it's own factory overclock (which is a fairly high 975 MHz) which is a problem because even if I underclock it it ignores the underclock setting when dual screening with video's playing (something to do with the cards media acceleration profile).

So, you guys think my best bet is to RMA it? I'm a little worried however that it will come back as not-faulty if I do as it seems to benchmark fine, and even run some games fine and is perfectly stable in general use.

 

[StarkyA]

Been going through various tests, set the power in CCC up to 20%, down clocked it to stock - the latter two reduce the frequency of the lock-ups, but not remove them all together.

So running at stock speed with with the power slider up gives me over an hour it seems, but there is no way short of bios modding it back to stock speeds when running dual screens (because CCC won't override internal settings).

 

[StarkyA]

have you enabled xmp for your pc's memory?

Yes, it's on profile1 in bios which sets the memory to it's rated 1600 MHz and runs it at 1.65 V, without it it drops to 1333.

 

[StarkyA]

Second from latest - the latest is a UEFI bios beta and I've read that people are having mixed results, where the latest standard bios is good.

Yeah I think I'm just gonna do that, if another card has the same issue then chances are it might be something else.

I've read (in another thread here with the same issue and other forums) that some people who've had the issue solved it by switching motherboards, and it might be a incompatibility issue between my gigabyte graphics card and my gigabite motherboard.

Still, the system was perfect and stable for months using a 5770 - so I think I'll have to RMA it.

 

[StarkyA]

Just played 3 hours of sleeping dogs without a crash when it is down clocked to stock speeds - but it crashes within 10 mins at the default factory OC.

Far Cry 3 is the same, seems my card gets unstable at anything past about 900 MHz.

Which given the default clock is 975, is pretty bad, going to RMA it for sure.