could my the graphic card (NVIDIA GTX 570) be the limiting factor in the refresh rate?
It is absolutely this.
The GTX 570 is too old to have a DisplayPort that can handle 3840x2160 at 60hz.
Update your GPU, the CPU can survive a while longer.
You can easily tell if your CPU is the limiting factor by looking at the CPU usage in Task Manager. If the whole CPU ...
For the 2070 Super vs 3060, the 2070 super is faster, but the 3060ti wins agains both. The 2060 Super is about the same speed as the 3060, but the 2060 Super can be easier to get because its older.
There are small power supply testers that will basically tell you if the power supply can reach the required voltages etc. But its very different to a load test, which will look at the performance of the power supply under load.
You mentioned that you have had this happen twice with graphics cards. Where they both using the same power cable form the power ...
A higher end motherboard doesnt matter much in performance with that cpu, its mostly the the gpu and cpu that matters. That prebuilt pc looks pretty good, especially with the high gpu prices right now. If the prices are going down, maybe you can get an rtx 3060 and a better psu, but that pc looks pretty good.
Your CPU is an i5 750 not 7500 according to your motherboard's specs.
You can basically install any GPU in it but you will be limited by the rest of your system which is 10 years + old.
I'll advice a 1050 Ti or RTX 3050 range GPU.
Unlike what was suggested above, be careful not to go for older/current gen high end gpu such as RTX Super series, your power ...