Upgrade my PC step by step for Resolve

Hey people,

I am a student filmmaker, low budget, you know what I am talking about. I just recently discovered my old gaming PC as a colorgrading and editing machine after spending the last 2 years with a good laptop.
Turns out the almost 7 old pc is acutally faster than the Laptop.

So I have an
Asus M4A88TD V USB3 Motherboard
AMD X4 Phenom 955 Quadcore CPU (thats 7 years wow)
NVIDIA GTX570 Graphics Card
8GB RAM
San Disk 128GB Windwos Drive
additional 128GB SanDisk Drive
Samsung 840 EVO 500GB SSD
BeQuiet 500W Powersupply


I do edit and grade mostly BMPCC ProRes and also Sony A7s AVCHD.
I do not really know how to start. I have a budget to upgrade one component, but which one would be the wisest to start with?

Thanks
Tim

[Tony Rivera]

I'd suggest looking here first.