Interesting GPU/CPU Usage

[Buzpilot]

If you disable hyperthreading in Bios, will it use 4 cores 100%, instead of 8 virtual ones at 50% ?

[Ailantd]

Not sure about this, but also could be that shaders to render terrain were a lot more expensive than shaders to render buildings. Also trees have a lot of geometry, same or even more than buildings at similar distances. If all this is the case that could be a lot less work to gpu in city that in landscape.

[335th_GRAthos]

You also need to look at the utilisation of the VRAM. The moment your VRAM is full, the GPU will start swapping in order to accomodate for the new graphics. This is when your GPU utilisation goes down (and your fps too) because the bottleneck becomes bringing the data in for the GPU to process them.

Test also flying over the same area above London a second time. You will see a much smoother fly-by the second time (provided the data is still in the memory of you GPU).

Over the sea you do not have any objects to load. Both GPUs (if SLI) work 90%
Over an "empty" (not a lot of objects) map neither. Both GPUs (if SLI) work 70-90%
Over the same map full of objects in order to max the available VRAM of your card, you see the problem. Both GPUs (if SLI) work 50-70%

Look at http://forum.1cpublishing.eu/showthread.php?t=23199

As for I/O I was just watching the HD access light which only blinked once or twice a second throughout the flight.

Once or twice per second HDD access is a lot (for me) and shows the amount of data that needs to be loaded.
For me this was solved and I got smoother gameplay by creating a RAMDISK and loading everything there. The new RAMDISK solutions posted in the forum are much more advanced than the ones I knew in the past and made the difference.

~S~

[InsaneDruid]

Most probably your GPU was the bottleneck over london. Not only Vram usage, as said above, but geneal computing power of the GPU. (Needs to shade all the buildings etc) Thus, the CPUs did not need to compute to their full power, as the GPU could not accept new instructions. (The maximum prerendered frames setting in your nvidia control panel affects this too, as this is the amount of frames the GPU renders ahead, if the GPU is stilly busy and does not accept the CPU date at the moment). When leaving london, the GPU usage decreased and now the CPUs could be used more, as the GPU was accepting new data faster then over london.

The fact that you see increased usage of the second GPU (not in SLI) when the first one saturated might be the nvidia driver using the 2nd GPU for the windows background processes.

[Icebear]

Originally Posted by 335th_GRAthos

You also need to look at the utilisation of the VRAM. The moment your VRAM is full, the GPU will start swapping in order to accomodate for the new graphics. This is when your GPU utilisation goes down (and your fps too) because the bottleneck becomes bringing the data in for the GPU to process them.

I noticed that too. The VRAM gets fully stretched within seconds after entering the scene. As far as I understood the VRAM cache gets cleared automatically to ensure that there is always enough free VRAM to run the application and to avoid that kind of bottleneck. IMO this does not work correctly as the VRAM is always around 100% workload.

[335th_GRAthos]

Originally Posted by Icebear

the VRAM is always around 100% workload.

No it is not Icebear, but you must have lots of it

It appears the max VRAM used was 2,1Gb over London (your mileage may vary depending on the resolution you play I presume).

So, if your card has 1Gb VRAM you need to be very consious on how much graphics detail and how heavy the map is you fly on.

My 1,3Gb VRAM makes many maps playable but I immediately notice when the limit is reached (halved fps).

~S~




PS. Antartica!? Say hi to the icebears from me, if you find them

[Stefem]

Originally Posted by Igo kyu

I suspect (I would welcome clarification from someone who really knows) that Hyperthreaded CPUs only ever run up to half speed, because there are half the number of cores that Windows thinks there are, and TANSTAAFL.

Windows recognize both physical and logical cores as independent unit, in fact prior to Win 7 the OS thread scheduler not even cared if a core was physical or logical.
The Windows task manager shows the average of all CPU cores usage including logical cores but also can show (depend on configuration) a graph for each core, whether it is physical or logical.

[Fall_Pink?]

Originally Posted by Stefem

Windows recognize both physical and logical cores as independent unit, in fact prior to Win 7 the OS thread scheduler not even cared if a core was physical or logical.
The Windows task manager shows the average of all CPU cores usage including logical cores but also can show (depend on configuration) a graph for each core, whether it is physical or logical.

The HT cores are just parked with CoD whereas the real, physical cores are active with CoD, but cpu power is not the issue with this game.

An i7 or fast i5 is more than enough. Heck, even when I underclock my cpu to 2.8 Ghz it still runs pretty good.

It's just the buggy 3d mode (full, pseudo..) and gpu clock speed that worries me. Sometimes the game starts and my vid card stays at 157 Mhz no matter what. I shut it down and change to pseudo, and all of a sudden the vid card is now at 850 Mhz. Next time, nothing has changed in between, it's back at 400 Mhz and sometimes even back to 157 Mhz.

This is really weird game behavior which is a bit unexpected.

Rgs,
FP

[EZ1]

For what its worth, when I watch CoD CPU usage I do notice that only the odd numbered cores show usage. The 4 physical cores I would guess.

[Stefem]

Originally Posted by Fall_Pink?

The HT cores are just parked with CoD whereas the real, physical cores are active with CoD, but cpu power is not the issue with this game.

An i7 or fast i5 is more than enough. Heck, even when I underclock my cpu to 2.8 Ghz it still runs pretty good.

It's just the buggy 3d mode (full, pseudo..) and gpu clock speed that worries me. Sometimes the game starts and my vid card stays at 157 Mhz no matter what. I shut it down and change to pseudo, and all of a sudden the vid card is now at 850 Mhz. Next time, nothing has changed in between, it's back at 400 Mhz and sometimes even back to 157 Mhz.

This is really weird game behavior which is a bit unexpected.

Rgs,
FP

Yep, but this is a driver bug, you can't blame devs for this