Is it better to upgrade my OS/RAM, or buy a new rig?

[Kali]

So my PC is shitty and slow and I'm getting sick of not being able to play any current games because Windows 7 32 bit (I know, I made a poor choice when building this PC.) is barely supported anymore.

My specs are as follows (Copied from speccy because i'm too lazy to upload a picture):

OS: Windows 7 Home Premium 32-bit SP1
CPU: AMD Athlon II X4 640, Propus 45nm Technology
RAM: 4.00GB Single-Channel DDR3 @ 668MHz (9-9-9-24)
Motherboard: ASUSTeK Computer INC. M4A87TD (AM3)
Graphics: 1024MB ATI AMD Radeon HD 5700 Series (ATI AIB)

I've been considering just upgrading to Windows 7 64 bit and getting 8gb of RAM for a while, but I'm wondering if that would actually be enough improve my PC to the point where it'd run modern games (GTA V, for example) even semi-decently, or if saving my money and just buying an entirely new PC would be a better option?

[JerryK]

just get a new pc, your specs are pretty dated overall, and go for windows 8 64bit rather than 7

even if you like 7 there's just no reason not to have 8 now, all good things come to end eventually and 8 is actually pretty good

[cecilbdemodded]

I have an AMD Athlon II CPU, triple core although I unlocked the fourth core, 64bit Win7, 4gb ram. and a 1gb Nvidia GTX 650 ti.

On the newest games, both the GPU and CPU bottleneck, although in different ways. First the CPU. In newer games there's so much going on, physics/Ai/view distance/etc, that older CPUs without L3 cache(like our AMDs) will limit your framerate no matter how good your GPU is. You can see this by lowering the resolution and noticing the framerate doesn't get much higher.

Newer games also need much more memory on the GPU than before. For new games I'd say the minimum amount you'd want is 2gb. That's for 1080p with no AA. If you want to go Ultra settings or higher res you will need more memory.

So yeah, new system time if new games are your thing.