Suitable GPU to increase performace

Solution
Yeah, as indicated by the comparison benchmarks here, even a 1050 Ti would offer multiple times the performance of the HD 4600 integrated graphics built into your CPU...
http://gpu.userbenchmark.com/Compare/Nvidia-GTX-1050-Ti-vs-Intel-HD-4600-Desktop-125-GHz/3649vs2168

Your CPU is quite good in terms of processing power, but the integrated graphics built into CPUs tend to never have the kind of performance needed for gaming at high settings. They're more intended for general desktop use, since putting the kind of 3D rendering performance that a dedicated GPU has into a CPU would complicate cooling and make the chip more expensive for people who wouldn't be using it for gaming.
You can use virtually any GPU on the market, this CPU is quite powerful. As long as it is only a single GPU, of course (shame about that low quality PSU, though...)

"Fairly cheap" is now hard to find unless you aim for really weak GPUs, which are completely unsuitable for this nice CPU of yours. Due to cryptocurrency mining craze, many mid-range and affordable GPUs are now terribly overpriced or simply out of stock. At this point, your best bet is probably Nvidia 1060 6GB, almost a no-compromise card for 1080p resolution, if you can find one for a reasonable price. If you want to go lower than that, you will have to settle for 1050Ti 4GB, which will still be able to play most games at medium-high at 1080p with nice framerates. I'd also recommend Radeon RX570/580, but they are nowhere to be found.
 


1050ti would be good for medium gaming in 1080p.

Would be a shame to get that GPU for such a powerful CPU tho... I would get a 6GB 1060 or a 8GB RX480
 


Simply because CPU is only one part of the equation when you measure gaming performance. GPU is the other part, and it is even more important. If you only game on integrated GPU, this is the primary reason for slow performance.

1050Ti 4GB would be like a day and night difference in your case, you will be very happy. But what I was trying to say - if you can afford 1060 6GB, then do it. Your CPU can drive even 1080, you are not limited by it, only by your GPU.

 
Yeah, as indicated by the comparison benchmarks here, even a 1050 Ti would offer multiple times the performance of the HD 4600 integrated graphics built into your CPU...
http://gpu.userbenchmark.com/Compare/Nvidia-GTX-1050-Ti-vs-Intel-HD-4600-Desktop-125-GHz/3649vs2168

Your CPU is quite good in terms of processing power, but the integrated graphics built into CPUs tend to never have the kind of performance needed for gaming at high settings. They're more intended for general desktop use, since putting the kind of 3D rendering performance that a dedicated GPU has into a CPU would complicate cooling and make the chip more expensive for people who wouldn't be using it for gaming.
 
Solution