GPU slow down after 30 sec idle in Snow Leopard

[clawhammer]

Hello!
I'm successfully installed Leopard 10.5.8 with QE/CI, everything smooth!
Now i have installed Snow Leopard 10.6 to the separate partition.
I also have QE/CI working, But! Animation of Expose, Widgets, any transitions are slow for a 2-3 seconds, and after several moving of windows, everything became smooth as in 10.5.8. But if i leave computer in idle, after 30 seconds screen blink with color lines for millisecond, and after 15 sec it blinks the same way, and when i press F12(widgets appear), transition become slow again!! After several clicks on F12, everything ok again!

OK here is my investigation:
I have downloaded app called Hardware Monitor, and there is a sensor called GPU LOAD %.
Results:
1) Smooth animation - GPU load =12%, you can switch Expose, widgets, everything ok
2) I leave computer in idle and begin count time - exactly after 30 seconds my screen blinks and GPU load =19%
3) After first blink i count about 15 seconds - and have second blink - GPU load = 29%, and still at this point after long time
4) I'm pressed F12, so widgets transition of course, very laggy at this moment, but after several clicks on F12 and animation became smooth! Look at GPU load = 12%!
5) This process i can repeat infinity times, and this is not SpeedStep! I control CPU Speed by CPU-x and it's independently works with GPU Load. So even i turn off SpeedStep and running on MAX=1833Mhz - GPU load switching at 29%.

So... I read many forums about blinking screen and somebody tells that the reason - Energy Saver option - "Better Battery Life" and we need to switch to Better Perfomance!
But, my hackintosh have not this options in Energy saver. A have only:
Put hard disks to sleep
Automatically redeuce brightness
Start up automatically after power failure

It's all very strange because 10.5.8 have not this glitch, and my video card 7300Go both QE/CI via EFI Strings.

So i also know that Nvidia cards can dynamically switch frequencies, but HOW CAN i DISABLE IT??? There is no monitoring software to control frequencies on MAC(
Also i update 10.6.to 10.6.4 - nothing changes..

P.S.
One little thing - i can't wake from sleep neither 10.5.8. nor 10.6. SleepEnabler.kext present in system and works. After switching to sleep - computer turn off everything as normal, sleep LED appeared (but it differ from windows blinking, here is it still light). After i'm pressing power button, fans begin blowing, but i have black screen, computer not responding. That is all.
By the way, I have patched DSDT with DSDT patcher and make SMBIOS.plist closely to real mac processor.


SORRY for bad English - i'm from RUSSIA! Peace!

 

[clawhammer]

Well, i found exactly, that in windows my Nvidia 7300 drop frequencies after 30 sec to 3d Low mode, and after 15 sec to 2D mode.
It means than new leopard driver also have this feature. From one side it's better, because save my battery.. from another side, video card rather weak and very slow in 2d mode frequencies. So how can i get lock my card in 3D mode? Maybe apply driver from 10.5.8?