Message
Re: [Logic_Cafe] Twice the Speed? / Imac option?
2005-02-02 by GAmoore@aol.com
In a message dated 2/2/05 10:05:57 AM, kamm@... writes:
CL 3 RAM which means it takes three clock cycles from
request to data available. If the 2nd CPU needs to access the RAM at that
same time, it has to wait for those full 3 clock ticks. Could it do
something else while waiting? Probably not. The decision to do something
else would, itself, consume CPU time and I can't imagine it doing anything
other than waiting.
I think all modern CPUs are "pipeline" machines. A command doesn't just execute. It goes through 10 or 12 stages, so at any given time 10 or 12 instructions are being processed. A memory call can be made on the first cycle and read on the 4th so its not a waste of time.