Cracked the GPU utilisation 'problem'

[Griphos]

You don't necessarily need or want either the GPU or CPU to be near 100% use, certainly not as some kind of general rule. Efficient use of either or both of the processors in a sim is a good thing. Of course, we're talking about some other sim than RW. :-) What you don't want, though, is one of them to be near max while the other is waiting on it, as Flier is discussing, because that's what is meant by bottlenecking. If the sim can do what it needs to while only using part of the processing power of both the CPU and GPU, great.

After the update, SSAA will indeed make the image very blurry. Bill has a fix for that over on another forum. It works well. Until the update, MSAA would fail to render particles, and so smoke and steam, from the cab view. Big pain. Some ATI cards seem to run SS better than MS. In general, it seems nVidia runs MS better than SS, although 1x2 or 2x1 won't take a big performance hit (just make things blurry). Perhaps they'll fix that in a subsequent update.

[TheFlier]

oh oh! That explains why the sky looks blurry sometimes for me. On the othet hand it did using MSAA too before and after the patch.

I agree with what you say, the CPU doesn't need to be at 100% if your still getting good FPS. The CPU creates the frames and stores them in the frame-buffer (or flip queue, or whatever), for the GPU to render. When the frame-buffer gets full (controlled by the frame-buffer size in the graphics-driver options), the CPU stops to wait for the GPU to catch up). So the CPU wont be working 100%, but the GPU should then be running at 100% (trying to catch-up).

There's all sorts of procedures in place to stop the CPU from sitting idle waiting for things.
The frame-buffer queue (usually three queued frames) so it doesn't have to wait too much for the GPU.
IThere's three levels of CPU data caches to reduce wait-times for data from RAM.
There's HDD cache to reduce wait-times for data from the disk.
There's smart routines for working on one lot of data while other data is being retrieved from the disks.
There's write-behind routines so the CPU doesn;t have to wait to confirm the data was written successfully.
There's Multi CPU processors so one processor can be in charge of retreiving data while other processors process data already available.
All these little things to try and keep the CPu as busy as possible...

But still we see less than optimim CPU usage in this game!
If the CPU wasn't idle waiting for things to happen it would be busy creating lots and lots of frames for the GPU to render. So exactly WHAT is it waiting for?

If I was getting 30-40 FPS and my CPU was only 50% active I really wouldn't care. It's when I only get 14-15FPS and my CPU and GPU are 50% idle that I get enfuriated and want to know why the system isn;t busier trying to give me better frame-rates?

If you have am employee who's sitting idle most of the time and your business is suffering you'd be concerned, right? But if he's mostly idle but business is booming because he's a genius you probably wouldn't mind so much - LOL

[peterhayes]

BTW guys the nvidia CP does not show SSAA for a very good reason in that it uses the more modern and more efficient CSAA.
Using in Nvidia CP enhance the application and setting 16XQ CSAA or higher and MSAA (or FSAA) in TS2012 gives some very good results on my rig.
Of course all results will vary depending on the type of card, cpu, RAM, OS, monitor size and video driver, etc, and we will see a diversity of graphics card settings that work well on different machines. Vive la difference!
PeterH

[PapaXpress]

I gave that a try and it didn't seem to make a difference.

[thecanadianrail]

it may become extremely useful to help someone discover if they need to upgrade their video card, CPU, or both.

all of the above..... (but i knew this before hand) thanks for this information, when i get a new pc in a month or two i will be able to get the best results off the hop!