Sometimes the expectations of our customers mystify me.
One of the senior developers at Microsoft recently complained that the audio quality on his machine (running Windows Server 2008) was poor.
To me, it’s not surprising. Server SKUs are tuned for high performance in server scenarios, they’re not configured for desktop scenarios. That’s the entire POINT of having a server SKU – one of the major differences between server SKUs and client SKUs is that the client SKUs are tuned to balance the OS in favor of foreground responsiveness and the server SKUs are tuned in favor of background responsiveness (after all, its a server, there’s usually nobody sitting at the console, so there’s no point in optimizing for the console).
In this particular case, the documentation for the MMCSS service describes a large part of the root cause for the problem: The MMCSS service (which is the service that provides glitch resilient services for Windows multimedia applications) is essentially disabled on server SKUs. It’s just one of probably hundreds of other settings that are tweaked in favor of server responsiveness on server SKUs.
Apparently we’ve got a bunch of support requests coming in from customers who are running server SKUs on their desktop and are upset that audio quality is poor. And this mystifies me. It’s a server operating system – if you want client operating system performance, use a client operating system.
PS: To change the MMCSS tuning options, you should follow the suggestions from the MSDN article I linked to above:
The MMCSS settings are stored in the following registry key:
This key contains a REG_DWORD value named SystemResponsiveness that determines the percentage of CPU resources that should be guaranteed to low-priority tasks. For example, if this value is 20, then 20% of CPU resources are reserved for low-priority tasks. Note that values that are not evenly divisible by 10 are rounded up to the nearest multiple of 10. A value of 0 is also treated as 10.
For Vista, this value is set to 20, for Server 2008 the value is set to 100 (which disables MMCSS).