That's strange I find. I mean there is headroom for the CPU. I understand at stock speeds that it doesn't. I tried stock at 3.1Ghz and the GPU usages are lower (but then again the CPU usage is really high). I have now overclocked to 4.3Ghz (was 4.0 before) and it's hard to tell if there's any improvements. 0.3Ghz might not sound like much but multiply that by 8...
I know Bulldozer doesn't have true 8 cores. The modules are in between 2 cores and hyper-threading. But still Battlefield 3 uses all the cores efficiently (the loads are spread over all of the cores). So I'm surprised that CrossfireX doesn't have enough CPU cycles available.
Can it be anything else?
Another question: if I set Battlefield to only use lets say 4 cores. Would that make it impossible for CrossfireX to use the remaining 4 cores? (as CrossfireX will be running for BF3) Basically what I'm thinking is that BF3 (with its physics and so on) run on 4 cores and the remaining cores CrossfireX can use. I'm just wondering if if it's better for CrossfireX to have access to full cores as oppose to eg. 30-50% of 8 cores and if it's possible to manually set this.