Strange CPU Scaling with Rift
First a little background. I recently built a new gaming machine. It's pretty much a monster and has eaten up and spit out anything I've thrown at it. Below are the main specs:
Processor: Intel(R) Core(TM) i7-2600K CPU @ 3.40GHz (8 CPUs), ~3.4GHz -> water-cooled and oc'd to a very stable 4.5 GHz.
Memory: 16384MB RAM
2 x NVIDIA GeForce GTX 570, SLI'd
Video cards and memory are vendor oc'd
So with that out of the way.
I've been 5-boxing with great performance. Running my background toons on low and my main on ultra, I'm getting 30-50 fps in Meridian. Using the standard core allocation from the guide on this site, my average cpu usage is 50-60% with a pretty even distribution between cores, although my 1-2 pair does see a bit higher usage than the other cores.
My gpu's aren't even breaking a sweat. I find it very strange however, that changing the settings on my primary toon from Ultra to Medium has very very little impact on my fps.
So, to experiment, I added a sixth account. I used a core allocation as follows:
1/2 - slot 1
3/4 - slot 2, 3
5/6 - slot 4, 5
7/8 - slot 6
With six toons running, I'm still getting good performance. My average cpu usage hovers around 65% with only half my physical ram allocated and still plenty of headroom for my gpu's.
Now, here's where it gets weird.
I added a 7th toon using this allocation:
1/2 - slot 1
3/4 - slots 2, 3
5/6 - slots 4, 5
7/8 - slots 6, 7
Considering the minimal performance impact in going from 5 to 6 toons, I expected 7 to scale in a simlar fashion. What's happening is completely different though. As soon as the 7th toon loads, my cpu cores all peg, my fps drops to about 5 and my gpu's are barely in use.
There's obviously a bottle-neck of some sort there, but it just doesn't make any sense to me why the sudden jump. I've experimented with several alternative core allocations. I've tried the running the 7th process outside of ISBoxer. Same result. Seems the 7th toon used several times the resources that the 6th one did. If 6 is all I can run, that's fine. I'd just like some insight as to why the scaling is as it is.
Can anyone enlighten me? Thanks in advance.
Edit: Added a screenshot of 6 accounts running : https://picasaweb.google.com/1108997373 ... 1464955970
Core allocation:
1/2 - slot 1
3/4 - slot 2, 3
5/6 - slot 4, 5
7/8 - slot 6, 1