However, games like metro last light will use my gpu 100%, but my cpu utilization is not 100% (it's more like 30-50% or something)
In addition, i play a game called Vindictus ( i think its CPU bound) and guild wars 2 (which also in general prob pushes my cpu to about 50-60% cpu utilization)
Question: If my cpu is not being utilizied to its 100% usage (monitored according to AIDA 64)..does this mean that upgrading to the I5 4670k Haswell CPU will not net me any extra frames? cause my amd phenom 955 always seems to be utilized at 30-60% in most games and its really giving me the impression that it's not being pushed to its utmost limits... and therefore im not sure if i should upgrade to haswell
That dosnt nessarily mean you wont benefit from higher frame rates. It could just be the games your using dont utilize 4 cores which switching to intel would yeild alot better performance. Id go with ivy bridge though its better priced and would be a huge upgrade from the phenom 2 x4's
Since the CPU is not maxed out... that means it wont bottleneck the system... and that means is not mandatory to be changed!
Switching from quad core phenom to quad core intel wont help you either with single core capable games. However switching to intel and a motherboard (and you must buy a new one since amd and intel have no interchangable sockets) which support virtu logic would benefit in your games as the internal graphic chip from CPU will help your GPU... for me that squeze another 15fps on same resolution and allowed me to maxout the in game graphics (from medium setting).
What are you talking about intel is way ahead in the single core performance are. Its only in highly multithreaded games that amd starts to even out with intel in the gaming department. Look at benchmarks of 2 threaded games intel dual cores like the i3 3220 beat out phenom 2 x4's by a long shot. Even some mulithreaded games like neverwinter the i3 3220 beat the phenom 2 x4's
Just take a look at http://cpuboss.com/cpu/AMD-Phenom-II-X4-955 and then talk. Difference between his phenom and i5 ivy bridge are so small... does not worth... plus he said he wanted to upgrade to Haswell... which is new and therfore not cheap.
And intel sandy bridge/ivy bridge is considered better because lower power requirements, and low freq => higher OC possibility... for high end CPU go with Xeon: http://cpubenchmark.net/high_end_cpus.html .