Cannot overclock HD3870s

[reflux]

Hello there people,

I've got two HIS IceQ3 3870s in a Gigabyte X38-DS4, all bought from this lovely site, and I can't overclock them. At all.

At pretty much any overclock, both cards fail the CCC test. And these failures occur at stupid settings such as 790/1150. Sometimes they are so bad that the GPUs will crash and I'll have to reboot. I've given up trying to run 3dMark with my cards overclocked as it can't complete a run. However, they are absolutely fine at stock speeds.

I ran ATi Tool the other day, and used the Auto Tune option. It keep increasing the memory clocks until it reached a certain level, and then as its supposed to do, it started dropping them after it detected artifacting. Except the artifacts kept appearing, and it never stopped dropping the memory clock until it got so low Windows crashed.

Both cards are running Sapphire BIOS' which I flashed to give them some proper fan control. They would overheat before as I couldn't set the fans manually. This BIOS also has the PLL fix included.

Anyways, the cards work perfectly at stock so I'm mystified at what is going on. It sounds like it could be a power issue?

I have this 880w Hiper PSU, and both cards have the requisite 6-pin power plugged in. I have also plugged the molex into the motherboard which is apparently required for running dual graphics...but still no joy.

Can anyone shed any light? Should I boost the PCI-E frequency for example?

Thanks

 

[MeatLoaf]

Dont you need an 8 pin connector to overclock these?

 

[helmutcheese]

Only to use ATI's own Overdrive.

You can still clock it with 3rd Party Apps, or bridge the Pins to get use of Overdrive.

 

[reflux]

Dont you need an 8 pin connector to overclock these?

There are only two 6-pin sockets, one on each card. These are two seperate 3870s, not a 3870X2.

 

[marscay]

i've had this problem before with my 2 3870's and it was a driver problem, i though my cards were hosed but they weren't.

assuming you're cards aren't overheating and it sounds like they aren't i would uninstall the drivers then reboot and run driver cleaner in safe mode, reboot again and install your driver of choice.

it doesn't sound like a power issue, a small overclock doesn't really put anymore strain on the system than @ stock.

you could try increasing pci-e freq, i'd be skeptical this will do anything positive but if the driver clean doesn't work it's worth a shot.

btw forget the auto tune o/c's ..just set manually and run a game or 3dmark.

 

[gt_junkie]

i've had this problem before with my 2 3870's and it was a driver problem, i though my cards were hosed but they weren't.

Hi Marscay,

What do you mean by hosed exactly? How were they acting?

I have a 3850 that is not allowing an overclock nor is it stable. I get lockups and minor corruption in 3D but it's fine in 2D.

How did you remedy your 3870 issue?

Cheers,
gt

 

[marscay]

heya gt

pretty much like i said above, just did a complete removal of all things ATI in my system and re-installed the drivers.

for me it was a crossfire problem, the first top card at least was fine but in crossfire wouldn't overclock a damn until i cleaned drivers - something there just got corrupted with all the benching etc i guess.

are you getting corruption at stock in 3d?? try completely removing drivers as i did above and reinstall ....i'd prolly use 7.12 they still seem the best for me.

if you still get problems at stock maybe the card is just faulty.

 

[gt_junkie]

if you still get problems at stock maybe the card is just faulty.

Cheers Marscay,

Done pretty much all that re: uninstall/reinstall and different cat drivers inc 7.12.

It's at stock and doesn't allow me to change clockspeeds at all. It won't auto in CCC, won't allow manual in CCC and won't even allow clocking in ATiTool.

Really does look to be faulty TBH.

Thanks for getting back about it though matey!

gt

 

[Scougar]

Don't forget to try the old pci-e 100mhz lock trick (or better 101/109/110Mhz)

Matthew