Radeon HD 4870The Radeon HD 4870 uses a similar GPU to the Radeon HD 4850. Frequencies are a little higher and it therefore uses and gives off a little more energy, justifying a more imposing cooling system that expels hot air from the casing.
System in idle.
System in load.
Graphics card in idle.
Graphics card in load.
Although its cooling system remains cool in idle, the back of the card shows a similar temperature to the Radeon HD 4850 which gives the impression of heating up a lot because, in contrast, its cooling system is very hot. Once in load, the Radeon HD 4870 gives off a lot of heat which affects the northbridge quite a lot. As is often the case, the power supply circuit is what gets hottest on the card.
Temperature and noise level readings
In spite of the fact that the card expels air (very hot!) from the casing, it significantly increases the internal temperature of the system, partly because the double slot takes up more space than for example the Radeon HD 4850, and this prevents the flow of air. Although the card doesn’t seem very loud, its cooling system unfortunately varies quite a lot which is very annoying.