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 a dozen times 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. All testing was carried out in an ambient temperature of 22°C.


While the Revolution 700's idle cooling performance might not look too impressive, this is due to its twin 80mm cooling fans being wired into the card's 4-pin fan controller, which is specifically set to adjust fan speeds so the card idles at a safe temperature, which, as you can see in comparison to the stock 4870 X2, is around 50°C. What is interesting though is how while the stock 4870 X2's GPU0 runs hotter due to being cooled by air already having been blown over GPU1, the R700's situation is reversed, with both GPU's receiving identical airflow but GPU0 better able to exhaust it via the ventilated PCI-bracket.


Switching to load is the real test of the 4870 X2 though, and here we see a big difference in GPU operating temperatures. GPU0 runs a full 18°C cooler than when cooled using the stock cooler and GPU1 a slightly warmer but still impressive 8°C cooler. Remember, this is despite the mild 50MHz (400MHz effective) memory overclock Palit has shipped the card with, and even with the monster proportions of the triple slot cooler, is still impressive.

Overclocking

We've grumbled a few times in this review already about how we feel Palit has been a little tentative with the Revolution 700's factory overclock, and were keen to see just how far the triple slot cooler would allow us to push this dual GPU titan. Using RivaTuner we gradually increased both the memory and core speeds in small increments, running a "Crysis Crunch": a battery of tests taken from our Crysis benchmarks, to test the stability of our overclock.

We were pleased, although also a little frustrated to find that the Revolution 700 turned out to be an excellent little overclocker, easily reaching the 800MHz core/ 1,000MHz (4,000MHz effective) speeds of Sapphire's watercooled 4870 X2 Atomic and then continued onward still. Our maximum stable overclock was 820MHz core, 1,020MHz (4,080 MHz effective) memory; an improvement of nine percent and thirteen percent respectively over a stock 4870X2, and much more likely to produce very visible performance improvements that the R700's limited stock overclock of just 50MHz (200MHz effective) to the memory. While mileage will obviously vary from GPU to GPU, it's very clear that there was still a lot of performance left waiting to be unlocked in this card