Subject: Re: Hardware questions
To: Don Yuniskis <auryn@gci-net.com>
From: David Laight <David.Laight@btinternet.com>
List: port-sparc
Date: 11/27/2001 09:22:31
> >> OK.  This also makes sense.  And, a rational tradeoff -- data
> >> on the SCSI will still *be* there when you get around to it
> >> a bit later; the network packet *won't*!
> >
> >Absolutely - unfortunately I came to the conclusion that the cpu is given
> >priority over the sbus on accesses to main memory.  This will slightly
> >improve SCSI benchmarks (the cpu will not stall on memory until it is
> 
> 
> Huh?  Oh, if using the *onboard* SCSI!  Presumably, the advantage
> disappears if the CPU has to talk to an SBUS SCSI...?
> 
> >looping waiting for the data), but has a serious, detremental effect on
> >network traffic when the cpu is trying to use 100% of teh memory bandwidth.
> >(I never did find out whether the relevant arbiter worked that way).

But the cpu is looping executing from its cache waiting for an interrupt,
no bus activity at all.

    David