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Jeff Dunlop said in a message to Lawrence Garvin:
 TW>> About network cards: what is the advantages of having PCI
 TW>> cards in the >WORK< stations?
 LG> None, if you're still using a shared 10Mbit/sec 10Base-T cabling system.
 JD> Are you saying ISA adapters get the same throughput as PCI?
Not at all. In fact, a PCI card can provide practical throughput more than 10 
times what an ISA card can do.
But, it doesn't matter much what the PCI bus bandwidth is if your network 
bandwidth is still only 10Mbit/sec.
 JD> My Intel ISA adapters get about 900kps, whereas the PCI get
 JD> about 1200.
'kps' ?? I'll assume kilobytes per second, but I'll question that you're 
getting any card anywhere near 900Kbytes/sec, and 1200Kbytes/sec is a 
theoretical impossibility.
Ten Mbits/sec is 1250 Kbytes/sec and that's the theoretical maximum of a 
10Base-T network -if- everything is working 100% to specifications.
The best I've ever seen is about 650Kbytes/sec and that was with a 3Com 
3C-509.
Nonetheless, I will concede that the PCI card might grant you a 10%-15% 
improvement in thruput at the PC, but that's more likely due to the better 
intelligence on the card, and not due to the PCI bus itself. The measurement 
of 650Kbytes/sec, 900Kbytes/sec, or 1200Kbytes/sec has to do with the network 
bandwidth thruput, not the PC bus thruput.
Even an ISA bus has a higher bandwidth than the 1250Kbytes/sec theoretical 
maximum of 10Base-T.
 JD> On one of the LANs I support, the stations with the highest 
 JD> peak throughput and frames/sec are consistently the 486 PCI 
 JD> machines. There are a few newer and faster P75 machines with 
 JD> ISA cards, and they are considerably lower.
Once again, I'll suggest that this is caused by the inefficiencies of the 
circuitry ON the ISA NIC, and not due to the increase in the PC bus.
lawrence@garvin.hd.co.harris.tx.us 
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