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Classic vs. Desktop runtime

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Hello everyone

I'm the developer of a free online multiplayer Tetris game. Some of the more advanced players complained a bit about jitter in our game. I'm not talking about multi-second stalls, but barely measurable stops in the millisecond range. First I thought that it was GC related, but couldn't find any evidence for it. I set the GC ratio to 10%. But some players said that the problem only appears on multi-core systems and can be solved by changing the affinity of the process to lock it to a single core. Then I changed the runtime from "Desktop" to "Classic". The beta testers told me that it improved the situation for them...

The documentation states:

The Desktop Runtime is the optimal choice for desktop applications running on single-CPU systems.

Note that using the Classic Runtime on the systems that support parallel execution, ranging from Intel P4 powered by the Hyper-Threading technology to Intel Core 2 Duo/Quad and up, may cause significant performance degradation.

Is there more information available on these runtimes? Any ideas on how to measure and tune the behaviour of the desktop runtime? Can multiple threads run in parallel with the Classic Runtime or will threads be multiplexed onto a single core? Any other ideas on how to reduce the jitter?

Cheers,

Simon

Btw: For those interested, you can find the game here: http://gewaltig.net/

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From your post I see that enabling the Desktop Runtime fixed the problem.

If that's correct, simply use the Desktop Runtime by default because the Classic Runtime works well only for vintage unicore processors.

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From your post I see that enabling the Desktop Runtime fixed the problem.

If that's correct, simply use the Desktop Runtime by default because the Classic Runtime works well only for vintage unicore processors.

It's the other way round. It's the Desktop Runtime that doesn't work that well for some people.

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Well, jitter is in the eye of the beholder. Could you prepare a test and scenario that demonstrate the problem, e.g. by reporting fps rate or something like that?

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Well, jitter is in the eye of the beholder. Could you prepare a test and scenario that demonstrate the problem, e.g. by reporting fps rate or something like that?

Unfortunately I personally cannot reproduce the problem on any of my test computers. FPS in the reported cases is consistently high, so it's not a general lack of performance.

I was posting because I was interested in more in-depth information about the various runtimes. Is that information available somewhere?

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