Upgrading Rig Need Advice

[GamingRig2010]

Whats up everyone, so basically have $300 max to spend on upgrading my system i built about two years ago.

Current specs:

MB: MSI 770-G45 AM3
CPU: Athlon II X3 2.7Ghz
RAM: OCZ Gold 2GB ddr3
Graphics Card: HIS Radeon 5770 HD 1GB 128 Bit
OS: Windows 7 Home premium 64 Bit
Power supply: OCZ 500W
Case: APEX Vortex 3620 Mid-tower

Going with the Phenom II X4 for my CPU upgrade and this RAM I found: Newegg.com - G.SKILL Ripjaws Series 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model F3-12800CL9D-8GBRL

But wondering since I still have about $180 to spend if I should try to pick up another Radeon 5770 and crossfire? But I'm guessing I'd need to pick up a 600W power unit if I wanted to do that? Also can you crossfire different brands of the same model graphics card? Since my current is an HIS 5770 but it was discontinued so Newegg only has a Visiontek 5770 now.

Anyways any advice or upgrade set ups would be much appreciated, thanks.

 

[PP Mguire]

Get a 650ti with your left over money and you wont have to worry about your PSU. It'll be more powerful than 2 5770s also.

Honestly, if I was you I would spend all the money in a GPU and an 8GB RAM kit if you only game.

 

[GamingRig2010]

Yeah all I do is game on it, so if I just keep my current CPU and pick up at the 8GB of ram I linked then I have like $270ish to work with, what do you think is the best I could run with that on my system?

 

[PP Mguire]

You have a few options in that price range. 7870, 660, or spring a little more for a cheaper 660ti.

 

[GamingRig2010]

Yeah I'm leaning towards that 7870, good deal on newegg, but lets say I had another 100 after I bought the RAM and GPU do you think it would be worth it to get the Phenom or is the Athlon X3 fine at 2.7Ghz? Mainly playing strategy e.g. Total War games etc. but do play shooters every now and then

 

[PP Mguire]

Long as you aren't paying more than 80 bucks for the Phenom then sure.