GPU is clocked down automatically when overclocked after 8 minutes of Starcraft 2

Hello,
I have an Asus N73JF with a Core i5-460m and a Geforce GT 425m with Optimus. The standard clock speed of the 425m is 560/1120/800 (core/shader/memory). However i read on several reviews that it can be overclocked easily up to 700/1400/900 so i tried 680/1360/880.

Running Furmark for 15+ minutes at high performance mode locking CPU speed also at 100% the GPU temperature never went above 72°C and the CPU was at about 65°C. No heat or performance problems or graphics errors. Everything was stable.

But whenever i run Starcraft 2, after some minutes the screen will turn completely black for a few seconds and when it comes back to the game the GPU clock is reset to default values. The black screen seems to be due to some task switch which takes place when the downclocking happens.
It's the same when i manually alt-tab out of SC2 and then maximize it again, probably due to optimus switching.

I checked the temperature graphs and GPU temperature didn't even go over 61°C in Starcraft 2 but it still somehow decided to clock it down. CPU was also only at 71°C.

Furmark ran without a problem at 71°C GPU temp at the higher clocks. Why would the system decide to downclock the GPU when running Starcraft 2 ?

 

my guess unstable clocks. I have run furmark and prime95 and they stayed at the overclocks but some games make my clocks crash. Not sure why. Btw that is a large overclock lol. Also are you keeping the shader/core ratio? not sure if that could be affecting it. Don't know your card sorry. Those are my best guesses

 

shader/core ratio is fixed at 2:1. I'm just wondering why it wouldn't just crash or overheat if the clock was way too high. Especially cause it worked fine with even higher temperatures in Furmark.

 

Do the clocks keep overclocked in other games (I mean: is Starcraft 2 the only game where such situation happens?).

This is a thought and I may be completely wrong, but: maybe this is a safety measure to avoid reaching certain set (very) high temperatures.

Hope this helps.

 

No other games installed yet on this new laptop. Just 3dmark06 and 11 which should come close to games. Usually I would expect a heat issue as well but with just 61°C in Starcraft 2 (i used the msi afterburner monitoring) there just wasn't any extreme heat going on.

 

As i said earlier my 580 980 1450 clocks are stable in furmark and 3dmark 06 and many games but several "crash" my clocks. Several things happen when clocks are to high.
overheats
freezes
artifacts
downclocks

I believe yours is down clocking because of stablity issues with the game. Not all games will crash it and not all benchmarks will either. I can run furmark prime 95 and get to 95-98C and stay there for 20 mins. Though when i play supreme commander 2 my clocks crash from 580 980 1450 to xxx 7xx xxx something. Cant remember the numbers off my head. It crashes to the "on battery" frequencies. I'll notice a 25-33 FPS go to a 10 FPS. This also happenes in Empire Total War as well. Some times they last for several hours sometimes a few mins. It varies for me. I ussually roll with lower settings for those games so its stable. Even if you liquid cool it there are still limits hardware can go to. My memory limit is 1000 and i got it at 980, which is good. Some people have issues getting past 950. I assume ur clocks are just too high and the gpu is downclocking. I recommend finding what is the max rated frequencies are. You may very well be trying to run it past those max freqs.

EDIT: You got a 25% overclock....i am assuming thats past the gpu's limits. That is a huge overclock. My gpu is limited to like a 7% overclock at best. Others can be overclocked by 25% and more. I think the 5850 can be overclocked like a banshee. 260m can't at all :/

 

Ok thanks for the explanation. The last time i actually overclocked was like 8 years ago back when it would just crash due to overheating if i raised the clocks by too much. I just tried 630/1260/860 which is still a 12,5% increase and that ran fine for over an hour of Starcraft 2. Gonna try to increase it bit by bit to find the limit where SC2 still runs fine. I just didn't expect any game that doesn't even use 100% GPU like Furmark to make the GPU hit it's limits earlier than Furmark.

 

look at the wiki of thee gpu and see if it stats the max settings for the memory and stuff