Cooling, Temperatures, Noise and overclock.
The Palit HD4870 1GB Sonic Dual Edition carries 3rd party cooling solution. So how does it really perform?
The answer to that question is “Simply amazing”.

The maximum full load temperature I have seen on this card is 67°C. And this was with my room air conditioner turned off and room temperature looming at 28°C. The cooling solution does its job very nicely.
Coming to overclocking. The card carries 1GB of DDR5 RAM. So I was not expecting anything spectacular clocking from the RAM itself. The card managed to be 100% stable at clock speeds of 845Mhz core and 1140Mhz Memory. This is lower than what I was able to clock my HD4870 512MB variant. But its still good overclock. And even at these clock speeds, the card never even touched 70°C.
The fan speed does change with increase in temperatures. And it starts to spin faster. But this cooling solution was much quieter than the stock cooling solution of HD4870. Overall I must say I was impressed by it.