Microsoft has released a new hotfix for multi-GPU users who, in certain scenarios, are encountering poorer-than-expected performance games and benchmarks under Windows Vista.
The software giant says that the issue occurs when games and benchmarks use multiple display adapters in a Linked Display Adapter (LDA)
Apparently, a small scheduling latency on a new Direct Memory Access (DMA) packet may be incurred by a multi-GPU configuration if the packet is submitted to a GPU which has previously run out of work and if another GPU in the multi-GPU configuration is very busy.
Microsoft says that, in some scenarios, significant starvation of one or more GPUs in the configuration reduces the expected performance in an application.
The fix isn’t available for direct download from Microsoft’s site – instead, you have to submit a request
to Microsoft’s Online Customer Services to obtain the hotfix. Microsoft explains that the reasoning for this is that the hotfix is only intended to correct the problem described in the knowledge base entry, and that the hotfix may receive additional testing before it’s included as part of Windows Vista Service Pack 1.
This isn’t the first multi-GPU-specific hotfix that Microsoft has released, as it released a pair of hotfixes
back in August.
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