It might be important to note that I have a 1680 X 1050 monitor. Before you tell me to buy a 1920 X 1080, I might be in a transitional upgrade phase, so I might have to buy parts incrementally. First, pretend that a better GPU is a good buy and I have a good monitor. Second, what effect would a screen like that have on the bottleneck?
Now, you're probably about to say, "why would you buy a $300 video card and match it up with a $120 cpu?"
Listen, it wasn't really part of my plan either. Actually, my specs were sort of a pilot to enable me to at least PLAY current games on acceptable settings. It just needed to WORK. I was supposed to bring things up to speed a few months later, hence only 4gb of RAM.
I had planned to upgrade other parts first, and replace my CPU farther down the road as games tend to be slightly more GPU bound. Therefore, I needed to extend it's life as long as possible. Take my crappy board for example. All it has are the essentials. Any cheap board would have done the job, but this had core unlocking. Sadly, I think my extra cores were disabled for a reason, but you understand my strategy here.
I WAS going to exchange my 550 for a 560, but then the 600 series came out. I was also informed that the 560 would only give a slight increase in performance. I disagreed, but wouldn't it be like spending $400 for a 560? Not very appealing. And the card after that is the 570, and I think it makes more sense to own a 660 if I am to spend that much.
As of the next few months or year, I might be in "transition" mode. As I won't be able to change everything at once, SOME if my parts probably won't sync perfectly with each other.
So with my OC of 3.8 GHz, what might be the extent of the bottlenecking? I'm braced for a long list of mixed answers.
Bottlenecking is a bit overrated IMO. You would have to do a fine comparison at lower resolutions to have bottlenecks that might be noticeable. Your setup will be just fine to be honest. Will it "bottleneck"? sure why not. Will it cause an adverse effect, nope.
Silly question, but why not go with a 7850, instead? It's cheaper and faster. The 660 is crippled by the bandwidth limitations imposed my nVidia.
As I understand it, the 7850's higher bandwidth comes into play at higher resolutions and the like. Exactly what res does it actually become prominent? If it's higher than 1920 X 1080 than I think I might stick my the 660. I'd rather spend money on components first and then monitors; what use is a monitor without good hardware?
I do however, understand the counter-point of "what use is good hardware without a good monitor?". I know it's valid.
So what it kinda comes down to is "Is the 7850 strong enough to run at resolutions of 2560 etc.?" Well obviously it COULD, but I'm not sure it could pull 60fps with all the eye candy turned on.
I'll have to study up on their performance a little more later, but if the card cannot handle those resolutions, than what use is the higher bandwidth?
In short your planned upgrade really has no down side. Your CPU will be ok to push the new GPU at your resolution and it will be equally fine or maybe better at 1920 X 1080 should you choose to upgrade to a higher resolution monitor.
From a performance point of view as well as for overall enjoyment of your gaming experience I would urge you to make the monitor upgrade to 1920 X 1080 your next priority after the GPU.
Maybe go to a local shop if possible and see the difference first hand before you buy ? You may be ok as you are, its a subjective thing at the end of the day different people have different preferences, you may not see the benefits of the increased image quality as being quite as important as others do.
Hopefully the link I have supplied will help you see the benefits of the higher resolution on a hardware level if nothing else.