Need to know for best i7 performance in wow with hyperthreading (HT) enabled:
Well, i had a full explaination going into the details of hyper-threading, multi-core, WoW process distribution, and calculation of the affinity mask. But, after typing all that towards the end it some how disappeared as i was typing.
But, it ultimately explained how you derive the best affinity mask setting for i7, which is 84. You can find this number in other posts and you can also find other numbers other people have used. But, the reason why i like to use 84 is because it sets wow processes to the last three cores. This saves the first core for the rest of your computers normal tasks, like processing internet bandwidth for the game.
To answer the question about reversed core/thread order on i7:
Edit: binary 8 digits/threads: 01010100 = 84
right to left =>
0 = core 1 thread 1
0 = core 1 thread 2
1 = core 2 thread 1
0 = core 2 thread 2
1 = core 3 thread 1
0 = core 3 thread 2
1 = core 4 thread 1
0 = core 4 thread 2
84 = 01010100
this sets the first thread for each of the last three cores. dedicating each thread of the wow game to one core each. I could write a full explanation why again, but i don't feel like it.
Anyone with a Nehalem i7 will want to and need to change the affinity mask. it more than doubled my frame rate in Dalaran, on the Ultra setting!
Off topic, but about performance, the shadows setting is a killer of frame rates. even for the best of graphics cards and pc's. I turned this down to 1/4 notch and greatly increased my frame rate and still keep that top notch quality of the game. I turned it off and it improves even much more. Depends on if you want to see shadows on the ground. it's up to you.
I play this game on the specified system below and on a 32 inch LCD televesion. these modifications allow me to play the game the way i expected it to be played. I turn on vsync and get 60 frames per second everywhere, but dalaran. I still get 50 frames per second in dalaran. Whereas before i was only getting 10 - 20 fps in dalaran on ultra settings and before the affinity mask change.
System
Edit: Windows Vista Ultimate 64bit Service Pack 2
Intel i7 920
Asus Rampage II Extreme MoBo
12GB Corsair 1333mHz
2x Gigabyte GTS250 1G SLI
Corsair 750W PSU
2x Western digital 500 GB 7200rpm hds non-raid