Club3D Radeon HD 6870 X2 Review – Two Barts XT go against the big boys
Heatsink removed – the 6870 X2 uses two 40nm Northern Islands VLIW5 based Barts XT (6870) and is clocked at 900MHz at stock.
A Lucid LT22102 PCIe bridge chip (48 lanes Gen 2) is used for onboard Crossfire communication between the two GPUs
16 x ELPIDA 128MB GDDR5 clocked at 1050MHz by default
For voltage regulation, the 6870 X2 is equipped a pair of CHiL CHL8214 (4+1 phase) PWMs, which supports voltage control/monitoring by I2C bus
CoolStream Cooling System
Actually made of 2 separate heatpipe blocks. Fans are made by Everflow (75mm T128010SU 0.35A@12v and 83mm T129215SU 0.5A@12v)