Overclocking 6870 slight problem

[titanic3]

Ello folks, I can't seem to overclock my Radeon 6870 past 950/1150mhz without the PC crashing if I go over by even one notch (951/1151 or higher will make it crash). It can't be a PSU problem because I have a Corsair 750W that is more than capable of powering a 6870. I'm using MSI Afterburner, is there something I can do to fix it and if not, what's causing it to be limited to 950/1150?

[Debrody]

Not enough voltage.
Sapphire trixx has a voltage slider if that works with your card.
Anyway i wouldnt overclock too much... just saying.

[zack1234]

Ati CCC has "Overdrive" built in for setting power, clocks etc.

Its a bit vague, you can have a big "Overdrive" or one thats sits in the CCC, the ovrdrive in the CCC which has to be enabled

I used that MSI just to monitor the settings, but it did strange things like rebooting my pc

I have stopped adjusting my pc now as its five years old

[MrRiplEy[H]]

There's no garantee that card in question is even able to overclock higher than that. Overclockability varies from sample to sample, sometimes a lot.

If your card is a reference design, overclocking it may produce high noise levels or even worse, high temperatures and can prematurely kill your GPU. If you plan to push the voltages etc and you don't have a special overclocking version of the card, don't be surprised if the computer just won't boot one day.

[Noir]

overclocking GPU is a pain...I have a Asus 6870 DirectCU II and I'm too scared to overclock it 

[titanic3]

Ah, gotcha. I was just curious how big of a difference in FPS I would get if I OC'ed it to the max. Wasn't planning on leaving it like that. It's a PowerColor 1GB 6870 if that makes any difference.

My previous card, a Sapphire 5570 that I left on max OC for 2 years, and used it at least 5 hours everyday is still alive and kicking.

Oh wells, no big deal, thx for the clear up.

[MrRiplEy[H]]

Ah, gotcha. I was just curious how big of a difference in FPS I would get if I OC'ed it to the max. Wasn't planning on leaving it like that. It's a PowerColor 1GB 6870 if that makes any difference.

My previous card, a Sapphire 5570 that I left on max OC for 2 years, and used it at least 5 hours everyday is still alive and kicking.

Oh wells, no big deal, thx for the clear up.

Your overclocked parts may well live a long life if they are good samples. A bad sample that would die in 3 years on normal clocks can however last only 1 year or less overclocked. YMWV - Your Mileage Will Vary.

[Debrody]

Titan,

the 5570 is basically an 5670 with DDR3 memory, and also greatly downclocked. Ergo, that chip was designed to run on ~800MHz yet its set down to 650 by factory default. In the other hand, the 6870 is nearly the maximum what the Barts chip knows - dont expect any wonders.

Also, in a mixed-limit situation (AH with high settings) if youre overclocking the GPU, it wont greet you back in the FPS. You have to find the actual bottleneck (CPU? which part of the CPU? GPU core? V-ram?) and only increase the required clock. For example, i have a phenom955-5830 combo, with the shadows turned off, increasing the GPU clock wont take any effect - the CPU core and the L3 cache is the limiting factor. With all the settings turned on, it becomes more GPU-limited though.

[titanic3]

I know AH is mostly CPU (check out the thread I posted in the General Discussion). After I went from a E7500 2.93ghz dual core to a Q9550 Quad 2.83Ghz, I can run AH at the same settings in 30+ players furball at 60FPS where I would've gotten 40-50 FPS before.

I'm more concerned about other games (Witcher 2, Rise of Flight, and Arma 2) are the few games I can't run at high settings (no AA/ubersampling, 1920x1080). But it's not really that big of a problem, I was just curious.

[cattb]

The 6870 does not overclock as well as the 6850. At least that is what I read when I was looking at them.
Good Luck