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From: Rick.Rashid@CS.CMU.EDU
Newsgroups: comp.os.mach
Subject: Re: Context switches? Or something else
Message-ID: <UZC_6Te00jdXB9bF46@cs.cmu.edu>
Date: 15 Oct 89 15:26:23 GMT
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For contrast, I did a couple of experiments on VAX based systems using somewhat
simpler programs and using a version of the Mach IPC code which I optimized a
bit over the summer.  Generally speaking, the relative performance of Mach
calls on Vax architecture machines is greater than on other Mach based systems
at CMU because more work historically went into the machine dependent trap
interface on the Vaxen.

Mach RPC (4 bytes of data both ways):  538 microseconds
Pipe RPC (4 bytes of data both ways): 2498 microseconds
Pipe Select ( ditto):                 3487 microseconds
Mach RPC (Mig interface version):      608 microseconds

All times were on a MicroVAX III.