Berkeley CSUA MOTD:Entry 30869
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2004/6/17 [Computer/HW/CPU] UID:30869 Activity:very high
6/17    For general purpose computing do you think a dual p3-700 with 100mhz
        bus is faster than a single p3-700 with 133 mhz bus?  When would the
        single cpu be faster?
        \_ For most applications, the bus speed will not matter. So you
           are looking at 1 CPU versus 2 CPUs. You may not receive any
           benefit to 2 CPUs, but they will not hurt. So the dual is
           almost always going to be faster. The exception is if you are
           limited by the bus speed (lots of I/O) and even then 133 is not
           much faster than 100.
        \_ Bus speed helps for applications that access memory in large
           "stride".  Having an extra CPU and not using it at all will actually
           slow the system down by 1-2% due to extra polling.
           \_ No, because the CPU will be used by the OS. Real benchmarks
              I have run show about a 10% gain on 2 CPUs even if there is just
              one non-threaded process running. The other CPU will never
              be 100% idle.
              \_ Sorry, I was refering to OSes which are not dual-cpu aware.
                 \_ From op: I'll be using windows XP.  Thanks.