Well cooled 4850 or not great cooled 4870?

I have the option of either a 4850 with a good heatsink for $120 or a 4870 with a slightly hot running heatsink for $153.

I will be running games @ 1680 x 1050.

I have a 500w PSU.

What would you guys choose?

PS. those USD prices are converted from my local currency!

I would go with the 4870, the cooler should be sufficient for stock speeds.

Get the 4870 and monitor your system temps.
If they're running too high considering running the top fan or adding another case fan.

Can you link to the cards in question? If not from a site in your country perhaps from another like Newegg (USA) or Overclockers (UK)?
Assuming the HD4870 has a reasonable cooler, it's the best way to go as far as performance goes but if you live in a hot climate it might be better to use the better cooled card and sacrifice some performance for a more stable system and less fan noise.

The HD5770 has similar performance to the HD4870, runs cooler and only needs a single power connector but it may be unavailable in your country or just too expensive

It means the PSU won't support a 4850 or 4870. Sorry.

Yep no probs:
Heres the : 4870
Here is the 4850

THe Q-Tec PSU:

o/p peak peak watt
+3.3v 28a 252w
+5v 35a 252w
+12v 18a 216w
-5v 1.0a 5w
-12v 1.0a 12w

OK; its an older style ATX version 1.x PSU. That -5v rail gives it away.
I don't believe it has enough +12V power for your system and the new 4850/4850 video card.

Here is a more modern ATX ver 2.x 400W PSU data label. Notice the much higher +12V rating - up to 380W. And no more -5v rail.

Do not play tf2 myself, but I think it's more CPU than GPU dependant. Source games in general do well with less powerful cards and Nvidia seem to have better Linux support than ATI so I'd suggest either a 9600GT or the low power 9800GT:

http://www.newegg.com/Product/Prod [...] 6814130518