Tutorial: We show you how to pull apart and improve your shiny new 6870 card's thermal performance.
With the launch of the AMD Radeon 6870 cards comes speculation - what exactly is running underneath the surface of these cards? Is there a benefit to pulling a new card apart? Are watercooling nuts going to like this card? Though the 6870 isn't as expensive or as fast as the 5870 it still has some kick to it for a decent chunk of money. With low availability at launch we've managed to get our hands on a reference design from XFX and perhaps more importantly: permission to pull it apart.
Underneath that black, glossy sticker is where the action is, where the card's processing core and memory chips reside. Alongside these important components is the power delivery system - in totality these combine to create an effective 151W of thermal energy (otherwise known as heat) that must be dissipated.
The 6870 accomplishes this in a way similar to the 4890, and its heatsink is quite simple: a large block of copper contacts the 6870's processing core with a thick application of stock thermal paste, passing the heat onwards to three 8mm copper heatpipes which bend neatly into a series of aluminium fins. Cool air is sucked in at the end of the card and passed over these fins, where it absorbs thermal energy, and the resulting hot air ejected through the bracket.
It's the stock paste that provides the biggest hindrance to performance. Running Furmark at overclocked settings (958MHz core/1153MHz mem) and the fanspeed manually set to 100% resulted in a maximum temperature of 68 degrees on factory paste. After following the disassembly guide and replacing factory paste with an appropriate amount of Noctua NT-H1 paste load temperatures under the same conditions were a whopping five degrees cooler - for free.
While five degrees at load doesn't seem that big a deal it could be the difference between stability and crashing, especially with warmer summer months rolling around very soon.
The 6870 isn't too exotic, but we still recommend a few things:
As always, we take no responsibility for damage caused to components. If you're unsure of anything, just don't do it. With everything said and done feel free to jump into the disassembly guide to see how the 6870 comes apart.
Issue: 137 | June, 2012