X-bit labs

Two vs. Three: Zotac GeForce 9800 GX2 Against 3-Way CrossFire ATI Radeon HD 3870 (page 5)

Category: Video

by Alexey Stepin , Yaroslav Lyssenko

[ 04/04/2008 | 12:18 PM ]

Temperature, Overclockability, Compatibility

Our attempt to overclock the Zotac GeForce 9800 GX2 was almost as successful as with the Gainward Bliss 9800 GX2 1024MB. We made sure the GPUs of this sample of GeForce 9800 GX2 were stable at 700MHz. The ALU frequency grew from 1500 to 1725MHz at that. The memory chips were overclocked from 1000 (2000) to 1100 (2200) MHz.

In our Chieftec LCX-1 system case with a 120mm fan on the back panel and a closed side panel, the GPU temperature was 93-95°C under load. That’s why we recommend you to be careful if you are going to overclock your GeForce 9800 GX2. Nvidia reduced the clock rates of the new card relative to the GeForce 8800 GTS 512MB because the GeForce 9800 GX2 is very hot even at its default clock rates and overclocking may lead to overhead.

We didn’t observe serious incompatibility of the Zotac card with mainboards, but it did refuse to start up on our Intel Desktop Board D925XCV. So, the card may be incompatible with some mainboards based on old chipsets like Intel’s 915/925 series. That’s not a big problem, though, as the GeForce 9800 GX2 is unlikely to be installed into an old system.