Sapphire Radeon HD 5970 2GB OC Edition Review

Under the Heatsink

Please remember that removing the heatsink from your card will void your warranty.


Once the heatspreader on the back of the HD 5970 is removed we can start to see some of the inner workings on this card. The heatsink is made out of a very thin aluminum and makes direct contact with the Hynix GDDR5 memory modules. These H5GQ1H24AFR ICs are rated at a massive 2.5Ghz DDR (5Gbps) at 1.5V which bodes well for overclocking (we’ll be covering overclocking in a separate article) and is laid out in an 8x128MB pattern.


There should be no doubt that the HD 5970 is a complicated card to make and we can now see why the cores are placed so close to the “front” of the card: the power distribution area is massive. It contains a quartet of huge solid capacitors as well as the much ballyhooed Volterra digital VRMs that can be programmed via software applications.


Here we have the true heart of this beast: the two RV870 cores along with the PLX switch that facilitates the communication between the two chips. We’ve also got a bit of mystery on our hands here. ATI advertises that this card was “designed to take full advantage of PCI-E 2.1 with (a) Gen2 PLX bridge” but it seems that this PLX chip is actually a PCI-E 1.1 / 1.0a unit . According to the number written on the heatspreader, this is a PEX 8547 unit that uses 48 lanes. We are guessing that ATI picked this particular switch due to its low latency when compared to the other PLX products.