Interesting CPU affinity results from WoW

[Denithor]

When you've got two full raid parties on each side (160 players) fighting for control of WG I have a feeling your CPU is carrying more of the load than your GPU. I run on an e8400 with a GTX 260/216 and even this system bogs down noticeably under said conditions. Dal at its busiest doesn't slow me a whit but heavy raiding definitely does require more horsepower than I've currently got. C'mon Intel - release i5 already!


Just for further info -

If you are into multiboxing with two sessions open on a non-HT quad-core you want to set the first session affinity to 3 (first two cores) and the second to 12 (cores three and four).

For a quad with HT enabled the numbers are totally different, should be 15 (first four virtual cores - encompassing the first two physical cores) and 240 (last four virtual cores - second pair of physical cores).


EDIT: And just for clarity - on a dual-core setup you won't even have this option available. The game doesn't bother to create the affinity file unless it detects >2 cores. Soccerballtux - what you needed was more processor power not an affinity change. <-- that sounds dirty, somehow...

 

[Idontcare]

Originally posted by: kami

Originally posted by: Idontcare

If you set it to 3 and run WoW with task manager in the background and then pop out of WoW over to the task manager how many threads does task manager show WoW was running and at what CPU utilization rate?

Same thing when you are now using 255...does it change the number of threads spawned and/or the effective utilization rate for the cores in any way?

See here: http://i43.tinypic.com/2d0b9eu.jpg

It looks like at 255 its using at least a small amount from each thread.

:thumbsup:

Thanks very much for generating the data.

It is an interesting result...I must admit I was hoping for something far more compelling to jump out of the task manager graphs.

What this does tell us though is that whatever "bottleneck" is involved with affinity setting "3", eliminating the bottleneck involves using little additional CPU power when going to "255" while somehow nearly doubling the fps.

The next "I wonder if..." to hit my mind is DPC...deferred procedure call...I wonder if affinity setting of 3 is somehow invoking DPC's (I have zero reasoning why this would happen, but...).

Let me find that link to the DPC detection software so you can easily run it in the background while WoW is playing, that will eliminate DPC as a suspect right away.

 

[Cheesetogo]

Thanks for the thread OP! With my i7, I went from 15-20 FPS in Dalaran to about 30.

 

[SunSamurai]

Originally posted by: yh125d

Originally posted by: Idontcare
Interesting indeed, I had no idea WoW was a CPU dependent game like that.

WoW is probably the most CPU limited game there is right now. So much so that 4830/9800GT can pretty much max out settings and still be held back by an i7 in the main cities

Exactly right. In a normal raid situation (25 people a few computer controlled things) framerate drops like a rock compared to soloing.

In situations like a battleground when everyone is bunched up and you have veiw distance to max, it will bring almost any system under 30FPS without and special effects like AA or AF turned up.

I do not see why Anand still has no way from Blizzard to get a nice bench properly made. Its pretty lame to keep seeing Crysis and other games benched but still not Wow? It only has 12million people playing for the past several years! What does crysis have? 1% of that?

It shouldent be "Can it play Crysis?" No. Can it play wow at max settings during a 25 man.

 

[NitroTurtle]

Guess I have a reason to upgrade now.

Should I look for an i7 or wait for i5?

 

[Denithor]

I'm personally waiting for i5. Although I really wish Intel was going to release the i5 4/8 chip on 32nm instead of 45nm. I may end up grabbing one of those 2/4 mainstream models to hold me over until they release a 32nm 4/8. But it seems like a 2/4 wouldn't really be much faster than my current e8400 so I'm a bit put out.

Still hoping for an i5/SSD/Win7 combo late this year.

 

[Idontcare]

Originally posted by: Idontcare

Originally posted by: kami

Originally posted by: Idontcare

If you set it to 3 and run WoW with task manager in the background and then pop out of WoW over to the task manager how many threads does task manager show WoW was running and at what CPU utilization rate?

Same thing when you are now using 255...does it change the number of threads spawned and/or the effective utilization rate for the cores in any way?

See here: http://i43.tinypic.com/2d0b9eu.jpg

It looks like at 255 its using at least a small amount from each thread.

:thumbsup:

Thanks very much for generating the data.

It is an interesting result...I must admit I was hoping for something far more compelling to jump out of the task manager graphs.

What this does tell us though is that whatever "bottleneck" is involved with affinity setting "3", eliminating the bottleneck involves using little additional CPU power when going to "255" while somehow nearly doubling the fps.

The next "I wonder if..." to hit my mind is DPC...deferred procedure call...I wonder if affinity setting of 3 is somehow invoking DPC's (I have zero reasoning why this would happen, but...).

Let me find that link to the DPC detection software so you can easily run it in the background while WoW is playing, that will eliminate DPC as a suspect right away.

kami, I finally found what I was looking for...if you have time do you mind using this DPC latency tool and check to see if the deferred procedure calls are any different for your rig (run it in the background while running WoW) depending on whether you use affinity of 3 versus 255?

 

[Dravic]

PH II 955 @ 3.8
4890 @ 950/1100

I actually get better performance when only selecting 3 cores (Affinity = 10) rather then distributing the load to all 4 cores (Affinity = 15). My guess is windows threading over the 4 cores begins to introduce some kind of thread thrashing over using 3 cores.

Beginning Ulduar 25 man before selecting vehicles
Settings everything maxed

Affinity 10 = 71 fps (allowed me to put on 4x AA 8x AF and go down too 51fps)
Affinity 15 = 51 fps

similar results in Dalaran

 

[soccerballtux]

Still confused as to why my e2180@3.4ghz was running 40% and I had FPS issues...even with resolution and effects turned all the way down...

 

[SunSamurai]

Here is the answer to your FPS issues; Blizzard doesnt give a crap about details like that anymore. The money machine is in full swing and more manpower is being directed into the new MMO.

 

[soccerballtux]

Originally posted by: aeternitas
Here is the answer to your FPS issues; Blizzard doesnt give a crap about details like that anymore. The money machine is in full swing and more manpower is being directed into the new MMO.

Has to be World of Starcraft.

 

[SunSamurai]

I would assume so, as a Diablo MMO would get in the way of Diablo III and not make much marketing sense.

 

[Phoenix86]

So I looked this up and it turns out this setting is not even enabled on my system, so it was defaulting to one core. However CPU usage was spread out over both cores in task manager. Figured I'd set it to 3 anyways for my dual core setup and the gains were visible. Panning around in Dalaran produced no stutter-lag and increased fps by 3-5. I had guildies set it, most had 2 physical cores not newer i7s and a couple doubled their fps in Dalaran.

Basically, this isn't just for people with newer setups.

 

[Senpuu]

Originally posted by: soccerballtux

Originally posted by: aeternitas
Here is the answer to your FPS issues; Blizzard doesnt give a crap about details like that anymore. The money machine is in full swing and more manpower is being directed into the new MMO.

Has to be World of Starcraft.

Actually, the new MMO they're developing was confirmed by Blizzard to be a brand new IP.

This core tweak makes me wish I hadn't quit WoW. Maybe I'll reactivate and see how it works on my i7 rig. I seem to remember rather a lot of stuff in WotLK made my old machine stutter like crazy and Dalaran was always a picture show.

 

[NitroTurtle]

Originally posted by: Phoenix86
So I looked this up and it turns out this setting is not even enabled on my system, so it was defaulting to one core. However CPU usage was spread out over both cores in task manager. Figured I'd set it to 3 anyways for my dual core setup and the gains were visible. Panning around in Dalaran produced no stutter-lag and increased fps by 3-5. I had guildies set it, most had 2 physical cores not newer i7s and a couple doubled their fps in Dalaran.

Basically, this isn't just for people with newer setups.

Placebo effect. The fact that the setting wasn't present in your config file indicates that it was using the default setting, which is 3.

 

[Sylvanas]

Just like to add I have also confirmed this on my i7, with the default setting I was sitting at around 21-25 fps in Dal, I log out and set it to 255 and now at the same scene I am now at 40fps. This is at 1920x1200 Ultra settings. Very pleased

 

[imported_Shaq]

Nobody posted these yet? CPU benchmarks for WOTLK.

http://www.pcgameshardware.com...-and-Core-i5/Practice/

 

[Zap]

Originally posted by: Shaq
Nobody posted these yet? CPU benchmarks for WOTLK.

http://www.pcgameshardware.com...-and-Core-i5/Practice/

So, their "SMT" is HyperThreading? Disabling it gains 25% performance?

 

[imported_Shaq]

Yeah it looks like the average goes from 44 to 55 turning hyperthreading off. And minimum increases from 30 to 41. Too bad. This game would really benefit from 8 threads.

A 920 at 3.5 beats the qx9770 at 4.0. The 860 edges out the 920 but it is using faster memory so they are likely even.

Here are video card benchmarks.

http://www.pcgameshardware.com...cards/Practice/?page=2

 

[MODEL3]

Originally posted by: VirtualLarry
Interesting that the OP in that thread seems to have a physical dual-core CPU with Hyperthreading (4 threads total). What CPU might that be? Since C2Ds don't have HT, and there are no dual-core/four-thread Nehalems yet on the market AFAIK.

Is it some sort of Pentium D EE chip? Did they make any of those with HT? Or is it an Intel Atom dual-core, since those chips DO have HT?

Do you remember the Pentium D 9X1 or 9X2 series?

Was the difference of the Pentium D 9X1 or 9X2 series with the regular Pentium D 9X0 series, the hyper threading?

 

[Idontcare]

Originally posted by: MODEL3

Originally posted by: VirtualLarry
Interesting that the OP in that thread seems to have a physical dual-core CPU with Hyperthreading (4 threads total). What CPU might that be? Since C2Ds don't have HT, and there are no dual-core/four-thread Nehalems yet on the market AFAIK.

Is it some sort of Pentium D EE chip? Did they make any of those with HT? Or is it an Intel Atom dual-core, since those chips DO have HT?

Do you remember the Pentium D 9X1 or 9X2 series?

Was the difference of the Pentium D 9X1 or 9X2 series with the regular Pentium D 9X0 series, the hyper threading?

The MCM'ed dual-core Prescott P4-based chips had their hyperthreading disabled. So they showed as 2 Cores and 2 Threads (2C/2T), not 2C/4T as VirtualLarry was pointing out the OP has. 2C/4T is something like what we'd expect for Clarkdale/Arrandale.

 

[MODEL3]

Originally posted by: Idontcare

Originally posted by: MODEL3

Originally posted by: VirtualLarry
Interesting that the OP in that thread seems to have a physical dual-core CPU with Hyperthreading (4 threads total). What CPU might that be? Since C2Ds don't have HT, and there are no dual-core/four-thread Nehalems yet on the market AFAIK.

Is it some sort of Pentium D EE chip? Did they make any of those with HT? Or is it an Intel Atom dual-core, since those chips DO have HT?

Do you remember the Pentium D 9X1 or 9X2 series?

Was the difference of the Pentium D 9X1 or 9X2 series with the regular Pentium D 9X0 series, the hyper threading?

The MCM'ed dual-core Prescott P4-based chips had their hyperthreading disabled. So they showed as 2 Cores and 2 Threads (2C/2T), not 2C/4T as VirtualLarry was pointing out the OP has. 2C/4T is something like what we'd expect for Clarkdale/Arrandale.

I thought Pentium D 9X1 series (and maybe 9X2, or it was 9X3?) series, had Hyperthreading!

Are you sure, that the Pentium D 9X1/2/3 series had not Hyperthreading?

EDIT*
VirtualLarry was correct he said EE!
I was just asking for the lower priced series of Pentium D 9X1!
Do you remember a Pentium 4 revision Cedar Mill?
I checked again, there was only Pentium D 9X0 series &
Pentium D 9X1 series!
I thought Intel to distinguish Cedar Mill CPUs from Prescott CPUs with the same features, it added 1 to their model numbers!

 

[Cookie Monster]

The only presler chip (MCMed prescotts) that had HT enabled was the Pentium Extreme Edition 965.

 

[soccerballtux]

Wonder if my dual core back then had a setting even lower than 3. Would explain why I would never get above 40%/core.
I reinstalled with my sig-rig and it "detected" it as dual core, maybe that's just the default setting. Edited and changed to 15, the setting for a quad core CPU.

I turned my OC down from 3.5Ghz to 2.2Ghz and FPS in Dalaran went from 38fps to 28fps. All cores loaded ~25-35%, no matter the clock speed.
So there would appear to be some nasty engine latency limitation where it can't utilize the other...oh...75% of the processing power that the CPU has if computation xyz hasn't been completed yet.

 

[monovillage]

My own experience with some of the CPUs on the list has me questioning the validity of their results.