Display and cpu problem

I just bought new 23" panoramic monitor to replace my 15", when I start playing games on 2045x 1152 resolution, monitor start to flick and there is horizontal line with pixalated lines, It happen when I played the witcher and Microsoft flight simulator x, When I checked CPU then I realised that its running between 80% and 100 % is this normal?? as well witchers memory usage was on 1000, 000 k I have Inter core 2 Duo E6700 2.66 Ghz 4 GB of ram, 750W psu and 8600 gts sli, as well I'm replacing my old graphic cards with nvida 275GTX will this solve the problem or I will have to chage monitor, overclock or replace the processor ?

With lower resolution there is no problem, as well since large monitors and high resolution required graphic card with lots of memory I think the porblme is with 8600 which only have 256 MB x 2

Update: Actually even in games like Track mania on lower resolution cpu is very high and monitor still flick

i would guess that your gpu's are having a hard time coping with that resolution. 8600's are not good gaming cards anymore, and at that resolution they are going to show their weaknesses really fast.

For the time being you could lower all the graphics settings and see if that helps, but to really support that resolution you should think about getting a new gpu.

sorry it's 2048x1152, btw my cpu is very low and i still get artefacts and flips, I will upgrade gpu soon. and since my procesor is running on around 25 Celsius I will overclock it for better performance since on high resolution cpu increase