New Build vs Upgraded GPU

[Brinson]

So this is my current system, built in 2011:

Motherboard: BIOSTAR A770E3 AM3 AMD 770 ATX AMD Motherboard
GPU: HIS H667FS1G Radeon HD 6670 1GB 128-Bit DDR3 PCI Express 2.1 x16
RAM: 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666) Desktop Memory Model PGD38G1333ELK
CPU: AMD Athlon II X4 640 Propus 3.0GHz Socket AM3 95W Quad-Core Desktop Processor ADX640WFGMBOX
PSU: Antec EarthWatts Green EA-430D Green 430W Continuous power ATX12V v2.3 / EPS 12V 80 PLUS BRONZE Certified Active ...

Case is an Antec 300 Illusion.

I've been pretty happy with the machine I built. When I built it, I had absolutely no interesting in gaming, so I picked the 6670 up for about $60...but now I kinda would like to do a bit of gaming.

If I were to upgrade the GPU, how reasonable of performance would I get on modern games?

I prefer Nvidia as I run a linux workstation for non-gaming and have become extremely frustrated by the Radeon linux drivers.

These are GPUs I was considering, from cheapest to most expensive.

GIGABYTE GV-N650OC-1GI GeForce GTX 650 1GB 128-bit GDDR5 PCI Express 3.0 x16 HDCP Ready Video Card - Newegg.com
MSI N660-2GD5/OC GeForce GTX 660 2GB 192-bit GDDR5 PCI Express 3.0 x16 HDCP Ready SLI Support Video Card - Newegg.com
Newegg.com - MSI N760-2GD5/OC GeForce GTX 760 2GB 256-bit GDDR5 PCI Express 3.0 SLI Support Video Card


So really looking for.


1. What kind of performance would these three give me?
2. How much of a bottleneck is my outdated CPU?
3. Can my PSU (430w) provide enough power for the GPUs?

Much thanks to anyone who responds.

 

[PP Mguire]

Your machine is rather decent if you decide you really want to game all you need to do is slap an FX 6300 in that board and you're set.

Your PSU needs to be upgraded though. Period. If you have enough cash the 760 is your best choice. Able to max out most all game at 1080p still and will last quite a bit.

Here is a PSU that will run any single GPU machine for years.
SeaSonic S12II 620 Bronze 620W ATX12V V2.3 / EPS 12V V2.91 80 PLUS BRONZE Certified Active PFC Power Supply - Newegg.com

 

[Brinson]

Yeah, but if I buy a new cpu, psu, and gpu...I'm basically buying a new system. So I wonder if I would be better off paying the extra for the motherboard and switching over to an intel build...

 

[PP Mguire]

Well I didn't say the CPU was necessary, only if you decide to seriously game later on. That X4 is perfectly capable of gaming still. I mentioned the FX 6300, but I misread your post thinking it said 970 rather than 770 on the motherboard. So, that upgrade option is out the window.

What absolutely needs to be upgraded is the PSU though regardless if you want to upgrade your GPU.