Tokenring vs Ethernet 10 years later 3741

Charles Mills

re: years later

microchannel 16mbit t-r card were going for something like $900-card

aggregate 16mbit t-r LAN had lower aggregate network thruput than 10mbit ethernet

individual microchannel 16mbit t-r adapter card had lower per card thruput than almost any enet cards and even lower per card thruput than the pc-rt 4mbit t-r 16bit isa card.

...................

there were 10mbit 16bit isa ethernet cards with numerous different chips ... intel (82586), amd (lance), and several others ... with list price in the $100-$200-card range but some starting to show up with street price approaching $50.

ethernet lan had normal aggregate effective thruput in the 9.5mbit range (was both higher aggregate thruput and lower latency than 16mbit t-r)

you could get effective 9.5mbit thruput from large percentage of many of these cards ... equivalent to aggregate effective lan thruput

...................

the 16mbit microchannel t-r cards had target design of terminal emulation with something like 300 sharing the same lan. it wasn't necessary that any individual card have any significant effective thruput (and went for possibly 10 times the price of compebreastive enet cards).

as more environments changed from terminal emulation paradigm to client-server paradigm ... you were starting to have server asymmetric bandwidth requirements with individual (server) adapter card thruput equivalent to aggregate lan thruput ... i.e. servers needed to have thruput capacity equal to aggregate requirements of all clients.

there were no token-ring card products that were designed to satisfy the server side of the client-server asymmetric bandwidth requirement (i.e. single adapter card capability of sustaining full aggregate lan bandwidth) ... while a large number of the enet card products provided individual cards that were capable of sustaining peak aggregate lan thruput (and went for something like 1-20th the equivalent 16mbit mircochannel t-r cards).

since a large percentage of all the enet card products could sustain 9.5mbit ... they worked well for both server deployments ... as well as peak instantaneous client use.