Article View: comp.protocols.appletalk
Article #5246Re: What is EtherTalk speed?
From: Brad Parker
Date: Wed, 14 Dec 1988 13:41
Date: Wed, 14 Dec 1988 13:41
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1259 bytes
From article <6047@hoptoad.uucp>, by tim@hoptoad.uucp (Tim Maroney): > A non-dedicated 8MHz 68000 cannot keep up with an Ethernet, period. 10 megabits per seconds / 8 = 1.2 megabytes per second. Reading words gives 600,000 word reads per second. (assume we have hardware which will read 16 bits into a register from the wire) 8Mhz cpu give 125ns per cycle; move.w An@,An@+ is 12 cycles (2 reads, 1 write), 12 x 125ns = 1.5 usecs/word Which means I can do 666,667 word copies per second. Doesn't this mean I could hand copy the bytes off the wire and still keep up? (assume the loop is unwound) Or did I miss something? I often do my math wrong, but (assume that the sender will send small bursts of "packet trains" which will give me some time to process the bytes in between "trains".) -brad -- Brad Parker Cayman Systems, Inc. Cambridge, Ma. brad@cayman.com
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Path: arc1-ca.pugleaf.net!utzoo!attcan!uunet!lll-winken!lll-tis!ames!mailrus!ncar!husc6!bunny!cayman!brad From: brad@cayman.COM (Brad Parker) Newsgroups: comp.protocols.appletalk Subject: Re: What is EtherTalk speed? Message-ID: <1731@cayman.COM> Date: 14 Dec 88 13:41:06 GMT References: <6047@hoptoad.uucp> Organization: Cayman Systems Inc., Cambridge Ma Lines: 25