What to upgrade?

[thegermanpulse]

Hey there. This is the first time I've ever posted on a forum so I'm very new to it, but thought I'd give it a shot to see whether anyone could help me.

2 years ago I bought a pretty slick gaming rig (I'll post specs shortly) and was able to play most games at 60fps, as I had hoped. However, there were still games that I battled to run at that speed on max settings, which bothered me quite a bit, because I spend R14000 (South African currency) on the system (which is about $1050 dollars) - basically my entire savings.
The system specs I have are as follows:
Graphics card: AMD Radeon HD 7800 series
Processor: Intel Core i7-4770k, CPU 3.5GHz
RAM: 8GB (7.89 usable)

Now, I do not know that much about computers, but I was led to believe and believed myself that what I bought was quite a good system (at least for then).
Here are a few games that suffered with performance:
-Metro 2033 and Metro Last Light (Without Physx, of course)
-GTA IV + V
-Battlefield 4
-Watchdogs
-Farcry 3+4
-Skyrim (when modded)
When I say battled with performance, I mean anything between 30 and 55fps. I know a lot of people would be okay with having 30-40fps in games but since I paid so much, I thought that 60fps would be possible for most (then recent) games.

I've noticed a few things which may help with my inquiry:
---When there are many buildings, framerate drops
---When there are forests, framerate drops
Essentially, when there is a lot to render, the framerate drops. To my knowledge, this has not much to do with RAM but rather the GPU.

As I draw this novel to a close, I'd just like to ask you what I should be upgrading in order to get the 60fps in games that I've always wanted, including upcoming games like Fallout 4. Do I need to Sli my Radeon card, or should I buy a new card all together? My budget isn't big, so before I start thinking of buying I'd just like to see whether anyone has some advice.

Thank you so much in advance, any advice is highly appreciated.

 

[thegermanpulse]

Sigh, that's what I feared. Alright, thank you so much for your time.
If I don't have the money for a new graphics card, I presume sli wouldn't solve my issue either, would it? Someone told me that it would double the particle processing but if you say that Vram will not be doubled, then I presume that they were wrong...
However, my CPU is still good, isn't it?

 

[thegermanpulse]

Perfect, thanks a lot man, you're a rockstar. At least now I know what's holding me back, will get myself a better graphics card when the opportunity presents itself, one that will hopefully last me a decade, if not a lifetime.
It's just a shame that the South African currency is so weak and the pay is so bad.

Thank you again so much for your time.