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-< Bricks - a networking performance demo >-
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Note 27.1 OSF/1 performance problem with Bricks 1 of 1
JEDI::CAUDILL "Kelly - Net Tech Support - 226-6815" 31 lines 23-APR-1994 08:28
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Heather Gray answered this in the alpha_osf_ift conference. See below.
She is an expert, btw.
The only thing I would add to her "throw away that DEFZA - get a DEFTA"
message is that, these days, I no longer turn off UDP checksum. For
that matter, I don't use UDP very much any more. Using DEC3000/400
workstations (with DEFTA), you can get 98Mbps using TCP without doing
anything questionable like turning off checksums.
<<< AOSG::$1$DIA3:[NOTES$LIBRARY]ALPHA_OSF_IFT.NOTE;1 >>>
-< DEC OSF/1 AXP V1.2 and beyond -- field test, etc. >-
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Note 5272.1 FDDI UDP performance problem 1 of 1
SMURF::HEATHER "Heather Gray" 13 lines 22-APR-1994 17:21
-< Nuke the DEFZA >-
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The DEFZA doesn't use DMA on transmit. While you might see a small
improvement on your numbers by putting the DEFZA in the faster
machine, and the DEFTA in the slower machine. I'd doubt you'd see much
over 50Mbit+/s. I think ~54 was the most I'd seen on a 3000-500.
Expect somewhere in the 78-88 range for a 3000-300 with DEFTA.
BTW, the unpst_sendspace and unpst_recvspace variables are irrelevant
to UDP - these are unix domain socket variables. The rest of your
variables seem to indicate you've covered everything that can be
tweaked easily in the software.
-Heather
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