All Intel i7 processors have been more of the same for several generations in a row now, save for the occasional half a thousand dollar six core CPUs that don't yield any real performance difference to merit the extra money spent. Ivy Bridge), and the 6700 has identical clock speed and number of cores unless you spring for the 500mhz increased clock speed model, just a couple of different software features and support for DDR4 memory, and perhaps more cache than some models (not the 3770, however) as far as I can tell. Out of curiosity, may I ask why you think the CPU is bottle-necking you and why you think the other two models you suggested would be better? An i7 2600 runs off of an older architecture than the 3770 (Sandy Bridge vs. Please note that there are different sockets and different motherboards will need to be purchased. An i7 6700/k is the most preferable option. I would suggest at least an i7 2600/k or better. I have an i7 3770 and it still bottlenecks my R9 390 in CPU intensive situations. Your CPU/Motherboard must also be replaced. I currently have the R9 390 and it doesn't perform as well as the 970 as GTAV is run on the DX11 API. That being said if you are going to go for a higher end card and want to exclusively play GTAV, I would suggest an nVidia card. In addition to the power supply I would recommend at LEAST a graphics card with the power being equal or greater than a GTX 660 ti or R9 270.
GTA 5 PC SPECS 1080P
If you want a decent 1080p 60fps experience then you will need to upgrade your power supply to at least a tier 2 or tier 3. So what needs updating/replacing and how much work needs done? So I need to update it but not sure what needs to be done to make sure I'm running GTA V on high settings with graphics enhancers/ENB's and plenty of modifications. Been involved in GTA IV for years and haven't gotten into GTAV b/c of my computer not being good enough. Hope it's not too much of a 'nooby' question bus basically.