Messages in this thread | | | Subject | Re: NE2000 slow interrupts safe? | Date | Fri, 17 Apr 1998 00:05:19 +0200 (MET DST) | From | (Rogier Wolff) |
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Richard Gooch wrote:
> On my tests I noticed quite a spread of times. When I send short > packets, then yes, the times are around a few hundred > microseconds. However, for longer packets, I was getting up to 2 > milliseconds. And my measurements were consistent with the results > other were getting with pSOS. I first instrumented almost the whole > interrupt handler, then later just instrumented the block transfer > routine and got the same results.
Rule-of-thumb calculation: ISA bus cycle costs 1 us (one microsecond). 1500 bytes -> 750 transfers (Ne2000 is 16bit card) -> 750 us.
I'd say 2000 us is quite long, 300 us is a pretty fast.
I guess that you can have ne2000's that are slower than others. Maybe 300 us was a PCI card?
Roger.
-- If it's there and you can see it, it's REAL |___R.E.Wolff@BitWizard.nl | If it's there and you can't see it, it's TRANSPARENT | Tel: +31-15-2137555 | If it's not there and you can see it, it's VIRTUAL |__FAX:_+31-15-2138217 | If it's not there and you can't see it, it's GONE! -- Roy Wilks, 1983 |_____|
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