Many factors affect how much increase in efficiency you can realize by multiple core or multiple processors. In a design with good infrastructure (such as a good server), you may get up to .85 times faster processing with two processors versus one, especially in a 64-bit design with plenty of memory and processor cache. This depends on the tasks being performed and how well the system and the OS can distribute the tasks over multiple processors, bus speeds and characteristics, memory (capacity and transfer speed) and even disk characteristics.
So, in an efficient computer with two processors and an OS and application(s) capable of taking advantage of multiple processors, two CPUs could get up to 1.7 (1.85, tops on a very good server) faster performance. But Tom's guess of 1.5 times is probably a more typical limit for two processors in a personal computer. In some cases, though, you may not see any increased performance. If you drive a powerful car through a parking lot with speed bumps, you'll probably go at about the same speed as any other car, for example. Also, in stop and go rush hour, that fast car won't help you go any faster. An OS or an application that can't take advantage of multiple processors (or processor cores) will run on one processor, so the second processor (or core) will not add anything to the performance of that application. Thank you, Mark Snyder -----Original Message----- Typically when you are increasing processor speed a number of things are happening which increase your speed more than just a mere multiple of the processor clock speed. when you go from say a 1.5 to a 3.0 you are not merely just doubling your speed, but you will notice far more bang. Why is that? I am not an engineer, but I know that motherboards, Front Speed Buss, Memory efficiency and a number of other factors help the speed throughput so it is not just a multiple but much faster. And yes there is some down side to all of it so that it is never a straight graph increase, but one that has all sorts of dips and valleys. Dual Cores lose some of their efficiency to a number of engineering things and such that I cannot possibly explain. How much do the newer Quad Cores lose? Stewart (Who will probably upgrade to a quad core when octocores come out.) At 09:27 PM 9/19/2007, you wrote: > >Increases of processor speed increase processing not mathematically > >but algebraically. (I may have the terms wrong but it is not 2+2+2, > >it is 2x2x2) > >Who told you that? Next time they tell you anything put your fingers in >your ears and sing la-la-la until they go away. > >Due to overhead of various sorts increases have diminishing returns. So >a dual processor is only 150% as effective as a single processor of the >same speed. Etc., etc. Rev. Stewart A. Marshall mailto:[EMAIL PROTECTED] Prince of Peace Ozark, AL SL 82 ************************************************************************ * ==> QUICK LIST-COMMAND REFERENCE - Put the following commands in <== * ==> the body of an email & send 'em to: [EMAIL PROTECTED] <== * Join the list: SUBSCRIBE COMPUTERGUYS-L Your Name * Too much mail? Try Daily Digests command: SET COMPUTERGUYS-L DIGEST * Tired of the List? Unsubscribe command: SIGNOFF COMPUTERGUYS-L * New address? From OLD address send: CHANGE COMPUTERGUYS-L YourNewAddress * Need more help? Send mail to: [EMAIL PROTECTED] ************************************************************************ * List archive at www.mail-archive.com/[email protected]/ * RSS at www.mail-archive.com/[email protected]/maillist.xml * Messages bearing the header "X-No-Archive: yes" will not be archived ************************************************************************ ************************************************************************ * ==> QUICK LIST-COMMAND REFERENCE - Put the following commands in <== * ==> the body of an email & send 'em to: [EMAIL PROTECTED] <== * Join the list: SUBSCRIBE COMPUTERGUYS-L Your Name * Too much mail? Try Daily Digests command: SET COMPUTERGUYS-L DIGEST * Tired of the List? Unsubscribe command: SIGNOFF COMPUTERGUYS-L * New address? From OLD address send: CHANGE COMPUTERGUYS-L YourNewAddress * Need more help? Send mail to: [EMAIL PROTECTED] ************************************************************************ * List archive at www.mail-archive.com/[email protected]/ * RSS at www.mail-archive.com/[email protected]/maillist.xml * Messages bearing the header "X-No-Archive: yes" will not be archived ************************************************************************
