Comments on: GeForce 7 and Water Performance

By: Karoliina Salminen

Karoliina Salminen — Sat, 16 Feb 2008 04:40:00 +0000

Actually the situation seems to be the following for CPU cores (running X-plane beta 21):
11500 pts/1 RLl+ 9:59 ./X-Plane-i686
11500 pts/1 SLl+ 0:00 ./X-Plane-i686
11500 pts/1 SLl+ 0:00 ./X-Plane-i686
11500 pts/1 SLl+ 0:00 ./X-Plane-i686
11500 pts/1 SLl+ 0:00 ./X-Plane-i686
11500 pts/1 SLl+ 0:00 ./X-Plane-i686
11500 pts/1 SLl+ 0:04 ./X-Plane-i686
11500 pts/1 SLl+ 0:00 ./X-Plane-i686

X-Plane uses multiple threads but rarely other than the main thread is utilized.

Gnome system monitor reports CPU utilization as follows:
CPU 1: 2%
CPU 2: 100%
CPU 3: 19%
CPU 4: 6.1%

(This changes over time, but it never reaches situation where two cores would have 100% utilization at one time).

Memory utilization is 1.3 GB for the X-plane process tree on our machine which runs X-plane on 30 inch monitor at resolution 2560x1600.

By: Benjamin Supnik

Benjamin Supnik — Fri, 15 Feb 2008 13:35:00 +0000

I think you are mixing up the PROBLEM (being CPU bound) with the SOLUTION (using more cores). I think you can have enough evidence to know that x-plane is CPU bound using simple performance analysis tools.

But I do not think you can know that multi-core (in particular using 4 cores or 8 cores or any specific number of cores) is the solution without knowing a lot more about x-plane's code than you could know, because the source code is not available.

I will comment about this more with your other post.

By: Karoliina Salminen

Karoliina Salminen — Fri, 15 Feb 2008 13:24:00 +0000

The water performance on GeForce 8800GTX by the way is excellent on Linux. Having all settings full does not slow it down at all (XP9 is slow for other reasons like not utilizing all CPU cores that are on the machine).