BF2 uses Both cores of X2 4400

[McGeyser]

About a week ago, the X2 guys here and I were doing Super PI tests. We discovered Super PI runs across both cores evenly, even though Super PI is not multi-threaded.

Last night I left task manager open to the performance tab and played BF2. To my surprise upon alt-tab back to desktop, BF2 was evenly using BOTH cores.

I have not installed the AMD proc driver, nor have I set affinity, I don't know if that has anyting to do with it yet.

Can someone else verify my claim here? I will check AOE 3 for simultaneous core usage. Even though these games and applications are not multi-threaded, it appears X2 can split the work load through the OS.

Please share your findings.

 

[Hacp]

Sounds weird, maybe your task manager is buggy?? I don't really know as I don't have bf2.

 

[Unkno]

are you sure it's the game that's using both cores and not one core running the game while the other running your OS and other programs...

 

[theMan]

what is the usage of each core?

 

[Buck Naked]

I use 2 monitors and usually have task manager open when playing games. On the games I play both cores are used. HL2 CS:S UT2004 BF2 SWAT4 Far Cry

It also is normally at 50% usage no matter how it's divided.

 

[ElTorrente]

yup 50% on both cores. I see this quite a bit, actually - on other programs also.

 

[McGeyser]

I definitely see activity on both CPU panes in task manager, when I alt+tab out of BF2. I trust task manager to show the proper core activity, as I have seen the proof while using Prime 95 from core to core.

My default affinity checks both cores to run BF2. I sometimes get false starts with BF2, and I have to forcibly end the task (BF2) and then start the game again. Everything then runs fine.


So I am wondering, does X2 with the help of the OS, perform load balancing automatically?

 

[Markfw]

Superpi only uses one core, at least in win2k. Look in taks manager for the processes, and superpi ony takes 50%.

 

[McGeyser]

I didn't know Win2K only uses 1 core for Super PI. XP and x64 use both cores for Super PI at 50%, as shown in the task manager CPU panes. If I use two simulataneous Super PI runs, both cores go to 100%.

 

[virtualrain]

Originally posted by: ElTorrente
yup 50% on both cores. I see this quite a bit, actually - on other programs also.

I have noticed this as well on my system. It just doesn't make any sense. If "it" (the OS, app, CPU, etc.) has enough smarts to use both cores, why not use both cores to 100%? What's limiting it to 50% per core? I suspect something is screwed with the way task manager is handling dual-cores and although it appears to be using both cores, it is really only using a single core to 100%.

 

[sheElf]

Well if u new to multi-proc system, 50% on both cpus in taskmanager means the apps/software are not multithread and i have no idea how this thing actually works. that is why it is best to set affinity for game on certain cpu.

 

[Velk]

It's just a windows task scheduler thing, I don't think it can work out how much load a given cpu in a dual core has. Hyperthreading shows much the same thing, for presumably similar reasons.

 

[Acanthus]

HT shows similar results for many games.

Dont rely on the windows performance monitor, it sucks.

 

[Hacp]

Task manager shows this playing guild wars in windows, but speedfan shows only 1 core is used. Case closed!

 

[IamTHEsnake]

Don't kid yourself.

The task manager reads the usage improperly. BF2 uses one core but windows, for whatever reason, shows it as using one.

Regardless of how many cores it uses, it handles the game quite well.

 

[McGeyser]

Why then are we able to run two simultaneous instances of Super Pi or Prime 95 for that matter, and still pull slightly higher times than single core counterparts, in a non multi threaded app?

 

[McGeyser]

What I am getting at, is this:

When Prime 95 has affinity set to core 0, core 0 shows 50% usage but activity only appears in one CPU pane, the core 0 pane. When two simulataneous instances of Prime 95 are run core 0 and core 1 show 100% usage and both CPU panes are maxed.

In Super Pi with no affinity set, the load appears 50% between both cores, activity on both CPU panes. When two simultaneous instances are run, both cores then go to 100% usage and full actvity on both CPU panes.

There appears to be a load balance occuring via the OS when no affinity is set.

 

[biostud]

Originally posted by: McGeyser

There appears to be a load balance occuring via the OS when no affinity is set.

Rather it sounds like when a program does not have a fixed affinity it shows up on both graphs. But only reaches 50% since it doesn't use the 2nd core.

 

[kylebisme]

Exactly.

 

[virtualrain]

Originally posted by: biostud

Originally posted by: McGeyser

There appears to be a load balance occuring via the OS when no affinity is set.

Rather it sounds like when a program does not have a fixed affinity it shows up on both graphs. But only reaches 50% since it doesn't use the 2nd core.

Thanks! That explains it.

 

[aka1nas]

Windows can schedule a singlethreaded app to spend some time on each core for load-balancing purposes. It works the same way on traditional SMP systems. Doing only this will never get you above 50% CPU usage for any individual app. You can of course run two instances of a single-threaded app, for example prime 95, on each cpu/core to fully load both CPUs/cores.

 

[miketheidiot]

Originally posted by: virtualrain

Originally posted by: ElTorrente
yup 50% on both cores. I see this quite a bit, actually - on other programs also.

I have noticed this as well on my system. It just doesn't make any sense. If "it" (the OS, app, CPU, etc.) has enough smarts to use both cores, why not use both cores to 100%? What's limiting it to 50% per core? I suspect something is screwed with the way task manager is handling dual-cores and although it appears to be using both cores, it is really only using a single core to 100%.

my guess it is actually ceasing to ru the thread on one core to run some type of overhead program, and then restarting the threadon the other core, and doe this several times a second.

 

[Bona Fide]

Hey, you're right. I never bothered checking before, but apparently the load is balanced. Mine fluctuated between 50/50 and 60/40.

 

[McGeyser]

Interesting points you have all brought up. Thanks for the replies.

I am still not convinced that the Task Manager monitoring window is errant. Core usage has been acurately shown when setting affinity between cores. The single threaded app's choose to fill both cores to 50% or halfway and then a second instance of a ST app fills both cores to 100%. The representation shown by the CPU panes, reflect this.

We all know XP and x64 are capable of using multi CPU. Without affinity chosen, the OS should function automatically to load the cores. Does anyone out there have a dual physical-CPU who can check, if not setting affinity, sets priority or delegates two single threaded apps between two physical CPU's in a balanced manner?

I understand X2 dual core shares the memory controller and that could be an explanation for the automatic loading between cores at 50%. I am however, not so sure that both cores are not being utilized in a ST app or game.

 

[piddlefoot]

wanna test that second core real good in bf2 ?

l play with 100 bots on my 4400+ dual gtx 7800 vid 2 gigs ram, it rocks, and l record using fraps, at 30 to 40 fps record , it rocks .................

try it yourself .....

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