Crossfire & Tessellation - the straw that broke the camel's back...

[Jos]

Well I figured it out. Upon closer inspection, it seems that the heatsink didn't have enough thermal paste and was not making contact with the GPU right where the tessellator was I guess... temps were 100% fine... go figure. At least it works now.

But why you have no problem when test it separately ??

[dogchainx]

Actually, they do have a hardware fixed function tessellator in there.

Oh, I know. But the tessellator is such a small portion of the entire chip and (probably) the heat generated.

Its like saying MMX doesn't work on my Core i7 920 because I don't have thermal paste in JUST the right area. But, i'm glad he got it solved.

[Rattle]

maybe i should take my heatsinks off and blow on the gpu's might have as much of a chance at being the reason.

[Vinas]

lower clocks to see if its something dodgy?.. psu maybe ? doesnt the pp&C 1k have crappy rails ?

They guarantee 1% regulation, 1% ripple. So they should be very good and reliable. If your PPC is out of those specs they'll fix or replace it.

[Kain665]

@ Dog, Hey, I'm just guessing. All I know is that one of my cards wasn't making full contact and it stopped it from working in CF. Probably would have crashed on it's own if I stressed it long enough (only did Heaven 2.0 for 10-15 minutes when testing). Everything works completely fine now.I had a similar issue with one of my cards when I was modifying the stock baseplates to accommodate the twin turbo pros - there was contact everywhere apart from one small part. GPUz reported everything fine except the GPU #3 temp which shot up to 163c. Adjacent temps didn't change much out of the ordinary.

[dogchainx]

Glad you got it solved. One of my customers wants either 5850 or 5870's in crossfire, so if I happen upon the same problem I'll know who to thank. =)

[Jos]

I have some problem with Sapphire 5850 CF : Dirt2 crash if i set crowd to ultra, unigine 2.0 crash if tessellation enable. But when i tried the card separately, they work fine.

I read on guru3d forum (this thread : http://forums.guru3d.com/showthread.php?p=3527481), the problem is the tessellation unit on the gpu.

If i have faulty tessellation unit on one of my card, why they work fine individually ???

[STEvil]

try reading this thread Jos.

[Blacklash]

For people using Crossfire, It might be worth while to make sure you're using the latest profiles.

http://www.rage3d.com/board/showthread.php?t=33961772

[Jos]

try reading this thread Jos.

Kain665 solution ?? It doesn't work for me, already tried that.

Read this :
- http://forums.guru3d.com/showthread.php?t=318451
- http://forums.guru3d.com/showthread....=1#post3530289