Optimal affinity settings

[Nemis79]

Hi,

I'm multiboxing 5 clients on an i7 920 setup using Keyclone. I read on this forum that the cores should be setup in Keyclone the following way:

wow1: 0+4
wow2: 1+5
wow3: 2+6
wow4: 3+7
wow5: 1+5

http://www.dual-boxing.com/showthread.php?t=24786&highlight=affinity

Is there anything else I should do to increase performance? Ie set the affinity in the config file? Kinda new at this stuff.

[Coltimar]

I haven't used Keyclone for a spell but with ISBoxer I use all 8 cores on each client. I, too, have an i7 920.

[alcattle]

Setting affinity in your program is the same as doing it in WoW and most of the time it is easier.

[Ghallo]

Well, if resolution impacts the CPU demand it would indicate to me that either you use the "all instances use all cores" or you split usage based on resolution. If you plan on using PiP ... I'd say go for all of them using all cores.

[Coltimar]

If I understand how Hyperthreading works, and I barely do, I think each game with access to all is the best regardless of the software you use.

[Ughmahedhurtz]

In general, you'd prefer NOT to use HT cores on your i7. Blue hasn't specifically stated not to use HT cores but they did state that if you tweak the affinity mask, make sure it isn't using _only_ HT cores. Keep in mind that HT cores are a software-emulated logical core. The only real hardware cores on an i7 are cores 0, 2, 4 and 6. Hyperthreading was teh awesome on older CPUs (~30% gains on P4 CPUs) but with the limited support for multithreading in WoW and the more advanced i-Series CPUs from Intel, it isn't nearly as much of a gain and can, depending on your motherboard's implementation details, be a net gain of zero.

See this thread for data on games vs "mathy" apps. http://www.tomshardware.com/forum/261564-28-core

[Fef]

Agreeing with Ugh here. After quite a bit of testing, I am under the somehow subjective impression that the best solution is to let all clients use all physical cores (i.e. not hyper threading virtual cores).

[Nemis79]

Ok, so if i understand this correctly, set all 5 instances of WoW in keyclone to use cores 0,2,4 and 6?

And no instances to use 1,3,5 and 7?

[Fef]

Yep.

[Ualaa]

Is 0, 2, 4, 6 only a stronger option then 0-7 for each wow ?

[Fef]

The machine I currently multi-box on is quite nice to do this kind of testing since it has 8 physical cores (http://www.apple.com/macpro/).

At first, I set Keyclone to use all 8 cores, at least that's what I thought, from the interface setting. Sure enough when I checked in activity monitor, the first 4 cores and their hyper-threaded counterparts were hammered, and the last 4 were doing nothing.

Then, I forgot about the keyclone interface setting, and set affinity in the config file to use all 16 cores. Some physical cores were at 100%, with some activity on hyper-threaded cores, while some other physical cores were left completely untouched. This doesn't feel like it can be optimal.

So I set affinity in such a way that all 8 physical cores are used, and not hyper-threaded cores. Now the load is much better spread, and no activity happens on hyper-threaded cores before all physical cores get loaded (which does not happen with 5 clients anyway).

So yes, it is a quite subjective opinion, but I would think it is a better option to set affinity only to physical cores (i.e. 0, 2, 4, 6).