Thermal Performance

To thermally test the cards we recorded GPU temperatures for each individual core using RivaTuner. Idle readings were taken at the desktop in Windows Vista 64-bit Home Premium with Windows Aero enabled, while the load reading taken while the GPU configuration was running our Crysis benchmark at 1,920 x 1,200 with 0xAA.

This is one of the most demanding tests in our benchmarking suite, and is sure to get those GPUs sweating. We didn't go higher because we felt that if we increased the load too much, some of the slower cards wouldn't deliver realistic numbers because they'd be bottlenecked in other ways.

All temperatures were taken with the cards cooled using only their standard stock coolers and running on our open air test benches, which have no additional airflow other than that present in the room.



We were initially quite surprised by the HIS Radeon HD 4870 1GB IceQ4+ Turbo's thermal performance, but upon closer inspection, we found that it's down to the fact that HIS has increased the default fan speeds - at both idle and load - by a significant amount. Typically, the reference Radeon HD 4870 1GB's fan spins at less than 1,000 RPM when it's idling and spins up to 2,250 RPM when the card is fully loaded.

The HIS Radeon HD 4870 1GB IceQ4+ Turbo, on the other hand, idles at 2,250 RPM and loads at approximately 3,250 RPM - this means that the HIS 4870 is much louder than the reference card at both idle and load and it's worth bearing in mind when looking at the thermal performance above. Of course, you could throttle these settings down a bit with an application like RivaTuner and you'll get temperatures more like what we've seen with the stock Radeon HD 4870 1GB we have.