I personnally wouldnt, not with Phenom x4. What make is the power supply?
MY prediction is that it will work fo a short while, then you will stil lstart to see the problems occur, then you PSU could just go, or it could damage another component.
for that card... you're looking at a minimum of 600w I think Radeon recommend a 550w and above, but you're better off going for a 650 considering its a x4) I have a HD4870 and an intel quadcore 6600 and the PSU blew a week after getting the 4870, and it was a 550w. I've now got a 750w PSU and no probs, it was a cheap one but it's working ok.
A 4850 needs about twice as much power (10 amps) as a 4670. A high quality PSU, such as the Corsair 400CX can run a 4850 in a typical system. A cheaper, slightly higher capacity PSU may not be able to.
I run a power hungry Q6600@3.2GHz with HD4850 on a Corsair 400CX.
As Jsc says, a quality 400W supply can be adequate.
A little irrelevant but I have an E5200 @3.5GHz with a HD4670 on a cheap Thermaltake 350W PSU and it hasn't had any problems thus far. However the HD4850 is worlds apart from HD4670 in terms of performance...
how does the hd4670 play, thanks for the replys
For a cheap system, not bad. I don't push the system mind. Would like to give you fps for COD6 and more modern games etc but I only really play TF2 and CSS on it.
TF2: 1366x768 High settings, 0xAA 40-50fps
CSS: 1366x768 High settings, 0xAA 150-200fps+ but that won't tell you much as its mostly CPU dependent and is really old.
To put things in perspective, I recently did a games review on my Dell Studio 15 Laptop which has a 2.1GHz dual core and a ATI Mobility HD4570 with 512MB of DDR3 (Mid-Low level laptop graphics card). Crysis was just about playable (20ish fps) with everything on low settings and DX9c.
The ATI Mobility HD4570 has 80 stream processors, 64bit bus, Core speed of 680MHz and memory speed of 800MHz.
The ATI HD4670 however has 320 Stream Processors, 128bit bus, Core speed of 750MHz, and GDDR4 memory speed of 1.1Ghz (2.1GHz effective).
Games on low/med settings and resolutions shouls be a doddle. I wouldn't worry too much.