I currently have a gigabyte HD Radeon 5670 which I have had for a few years and I am now looking for an upgrade I am looking to run most games on high as well has record at a 1920x1080 resolution.
The motherboard I currently have is a Aus Rock H61M/U3S3 so I am not quite sure what will actually fit or work in it I also have 750w power supply so power that shouldn't be much of a problem.
the price would between $100-$250 preferably around the $150 to $200 mark but $250 is fine if its worth it ask me any more questions about my computer if you need to I would prefer for a Australian website to buy it of thank you
For a graphics card, I'd recommend a 7850 (newer generation) or 560 Ti (previous generation). Completely dependent on which generation you want. The 7850 is a stronger card overall. You will hit lower frames while recording.
In the U.S. it's running at the top of your budget.
I would go with the hd 7850 if you are choosing between it and a gtx 560ti, it costs $10-30 more, but it is significantly better. It is better than a gtx 560ti, and a gtx 570, and in some cases it gets close to or even matches a gtx580. However the hd7850 has more vram, and I think it will be better for what you want it to do. Your motherboard comes with one pci-e x16 slot, and its a bit old but it should be able to handle a hd7850, or a gtx 560ti as it has a x16 slot. Also your power supply as you said will not be a problem.
There is practically little difference. Only higher end cards will see a slight hit in performance. Mid-range cards have a little hit in performance. And low-end cards will practically not see any performance difference. Also, some cards can't max out a x16 2.0 slot.
No difference in performance at all. Yes pcie 3.0 has more bandwidth but todays cards don't require that much yet, so you will see no difference at all with a hd 7850 running in pcie 2.0 or in pcie 3.0. Even if you ran two cards in crossfire which your motherboard can't do there would be little to none visible performance difference. The only time you would see a difference was if you ran 3 or four cards in crossfire or sli.