BF2 and HyperThreading CPUS vs DC/Duallies...

[bob4432]

would i be correct in assuming that since the os(windows) sees a hyper threading cpu as 2 cpus(1physical cpu, 2 virtual cpu, P4C), bf2 would treat a p4 ht machine in much the same manner as it would in regards to cpu utlization as it would with a x2 or dual processor machine?

 

[stevty2889]

BF2 isn't really multithreaded, so it only uses a single core of an X2, and will pretty much ignore the hyperthreading as well, so yeah I guess it would treat it the same way..

 

[bob4432]

any other thoughts from anybody else?

 

[AmberClad]

I asked this in the highly technical forum, and they basically said that with an HT processor, the 2 virtual cpus aren't neccessarily doing or capable of the same workload. The second virtual proc would only have the resources available that the process running on the first virtual proc wasn't using. So if BF2 needed 75% CPU utilization, then I guess the second virtual proc would only have 25%. I may have misquoted that...

 

[bob4432]

thanks for the information, i think i will run some test here with known smp software and known non-smp software and see how bf2 relates since i can turn on and off ht.

 

[Markbnj]

[BF2 isn't really multithreaded, so it only uses a single core of an X2

This is incorrect information that for some reason known only to God continues to be repeated no matter how often it is corrected.

Oh wait, this is the Internet.

 

[stevty2889]

Originally posted by: Markbnj
[BF2 isn't really multithreaded, so it only uses a single core of an X2

This is incorrect information that for some reason known only to God continues to be repeated no matter how often it is corrected.

Oh wait, this is the Internet.

Ok, let me re-phrase it to make you happy, it's not SMP aware, so it won't take advantage of the second core. Most people look at multi-threaded as being able to run separate threads in parallel, we realize that games have more than one thread going at a time, but it's not SMP aware.

 

[Markbnj]

[Most people look at multi-threaded as being able to run separate threads in parallel, we realize that games have more than one thread going at a time, but it's not SMP aware.]

Windows schedules threads onto multiple CPUs, not the app. All of the parts of the Windows operating system that the game uses to do its stuff are multithreaded. The game executable itself is multithreaded. With the beta nVidia drivers BF2 consistently utilizes 50-70% of both cores, indicating that the app doesn't need to be specifically designed to be "SMP aware" in order to take advantage of multiple CPUs. Without those drivers it still manages to use 20-40% of the second core.

 

[stevty2889]

I've got BF2, and the Nvidia beta drivers, and I haven't seen the same results myself..

 

[bob4432]

i did some tests, not sure if this proves anything but this is the data i got:

BF2 CPU Usage

if anybody with a true duallie, x2, pentium D or a different single core cpu wants to send me a performance graph i will put it up so we can all see what different cpus do with bf2. just make sure the screen print is over 750px wide and also send the machine info to my listed email.

 

[bob4432]

any other thoughts on this??

 

[gac009]

how are your framerates in BF2 with HT on and off?

I know the Nvidia drivers are supposed to have new multi-threading support so dose this mean that Nvidia cards with the new drivers on a P4 w/HT have a performance incresase that I cant get with my ATI drivers?

 

[bob4432]

Originally posted by: gac009
how are your framerates in BF2 with HT on and off?

I know the Nvidia drivers are supposed to have new multi-threading support so dose this mean that Nvidia cards with the new drivers on a P4 w/HT have a performance incresase that I cant get with my ATI drivers?

i am going to re-run the test with fraps on and see what the fps difference is. but i couldn't tell a difference when playing.

 

[bob4432]

anybody know where i can d/l some bfrecorder files for a accurate fraps reading? trying to play and run fraps is not very consistent...

 

[DaFinn]

On my dual xeon box BF2 uses ALL "4" Processors that are available (2 physical + HT). I ran in the beginning some tests with HT on/off and assigning all tasks to 1 processor. I didn't see special difference in framerates, only that using both processors with ht on there are NO annoying slowdowns when you run around a corner and come to a shootout w. 30 guys shooting each other + helicopters + planes +++...

Good thing on a duallie box is, that I can rip a dvd or burn one while playing wihtout any slowdowns...