David,

What you experienced here is something a number of people have seen and I have no explanation for it.

What we see when people run the PPBM4 benchmark test on the same hardware with CS4 and CS5 they find that the AVI test takes about twice as long under CS5 with MPE turned off and nearly 4 times as long when MPE is turned on.

For example my results:

CS4: 1.4
CS5: 2.9 with MPE off
CS5: 5.4 with MPE on

If anybody has a logical explanation, I would like to hear is.

Its the GFX card that is being clocked down.

Download CPU-Z and you will see the speed differences.

Mine is flicking from

CORE: 300mhz
SHADERS: 600mhz
MEM: 100mhz

to:

633mhz
1404mhz
1131mhz

Pretty sure is will cause the slow lag

David,

This does not explain the deterioration from 1.4 to 2.9 with an ATI card, just by the move from CS4 to CS5.

CPU-Z does not show any changes in Core, Shaders or Memory, they remain stable at 721, 1442 and 1880 MHz. Is there any way to allow for real time updates to the display of CPU-Z, or are you talking about GPU-Z?

Not sure about the ATI card setup.

Here is what CPUZ is telling me - cpuz.png is the standard use with no 3d stressing. 01 is with it stressed a little and you can see the clock speed has gone to full speed.

And 02 is the meant to turn off this down clocking.

GPU Z causes the card to run at full speed. Have CPU and GPU Z open and close GPUZ and watch the rates return to lower clockl?

Well as a little test I ran the PPBM4 while GPUZ was open forcing the card to run at full speed - Confirmed in CPUZ

MPE on with GPUZ Open:

21.9, secs Total Benchmark Time
8, secs AVI Encoding Time
7.9, secs MPEG Elapsed Time
6, secs Rendering Time

MPE without

23.1, secs Total Benchmark Time
8.1, secs AVI Encoding Time
8, secs MPEG Elapsed Time
7, secs Rendering Time

So maybe the down clocking of the GPU isnt effecting it and its something else?

Makes no difference here.

Mine changes but doesnt seem to make any difference anyways.

Hmm