Microsoft has released a hotfix to resolve an issue that, in some cases, could cause systems running Windows Vista with SLI or CrossFire configurations to “perform more poorly than expected” in both games and benchmarks. The issue occurs when the games and the benchmarks use multiple display adapters in a Linked Display Adapter (LDA) configuration.
According to Microsoft, the issue is caused because in some scenarios a GPU or part of a GPU link may incur a small scheduling latency on a new DMA packet. While the hotfix addresses this problem, it is not freely available for download. Instead, users must visit this page and submit a request to Microsoft Online Customer Services to obtain the hotfix.