Mixed Vendor 7900 GTX SLI

Introduction

In November of last year, NVIDIA's ForceWare Release 80 brought mixed vendor support to SLI. This support allows users to run an SLI system with two of the same GPUs from different manufacturers. In other words, with ForceWare 81.94 and later, you can use a GeForce 6800 GT from manufacturer A with a GeForce 6800 GT from manufacturer B in your SLI system. Or, you could pair a Leadtek 7900 GTX Extreme with an XFX 7900 GTX XXX, which is just what we happen to be testing today.

Remember the following points when mixing vendors for SLI:

• GPUs must match (ex: 7900 GT with a 7900 GT and not with a 7800 GT or 7900 GTX)
• I/O ports don't have to match (ex: VIVO cards can be mixed with non-VIVO cards)
• Clock speeds don't have to match
• Memory sizes don't have to match (although it is recommended)

Some of you might wonder why anyone would ever want to mix vendors when setting up an SLI rig. Well, the truth is there are a lot of gamers out there who save up to buy one card to install on their SLI motherboard and then stumble upon a good deal for another one from a different manufacturer later. Rather than having to sell one of the cards to buy a new one from the other manufacturer, they can just use them together. Less hassle, more gaming.

We actually have received questions recently about mixed vendor support, so we hope this article will be helpful to some of you. Although NVIDIA has supported it for over five months, many users either aren't aware of mixed vendor support, or they just don't understand it.

The main purpose of this article initially was to show 7900 GTX SLI performance, but since we didn't have a matching pair of 7900 GTXs, we had to utilize a mixed pair. This allows us to also cover mixed vendor support at the same time. So, follow along as we take a brief look at mixed vendor 7900 GTX SLI performance.