This is not a question but an answer for people that are looking to replace their Radeon 4870 for a Radeon 5770.
The Radeon 5770 is yes better than a 4870 and uses less power than a 4870 also runs much much faster and smoother so if you are looking to replace a 4870 with a 5770 and don't want to spend a lot of money for a more expensive card the 5770 is a good budget card and performs very well.
I own a XFX Radeon 5770 1GB DDR5
Core clock @ 900Mhz
Ram clock @ 1200Mhz
1x 6-pin PCI-E power connector only using 75w of power
I am running Just Cause 2 at max everything with directX 11 with 75fps.
This card is a must if you are looking for something to hold you over until you can get a greater card later.
Its silly to replace a 4870 with a 5770, if you have a 4870 you really should be looking for at least a 5850 or 470 to have a reason to get a new GPU, otherwise you are just wasting $150 on bonus features and slightly lower heat and no additional performance. Seems like a bad deal to spend $150 for triple monitor support and a bit less heat to me.