Pritch5000
Technical User
We are testing on a DL740 with 4 physical Xeon processors, Win2k3 and SQL2K. I know the OS is hardcoded to use CPU 0 - so in all of our tests this processor shows a little higher utilisation but i will ignore that when I explain the following.
Can anyone explain why the following happens?
Test1 - allow SQL to use all processors. CPU 0,2,4,6 show no performance. CPU 1,3,5,7 are heavily utilised. This equates to both logical processors on every second Xeon.
Test2 - disable 1,3,5,7. CPU 0,2,4,6 are now used heavily. Two Xeons are now disabled.
Test3 - disable 4,5,6,7 (i.e. all the second logical CPUs on each Xeon). CPU 0,1,2,3 are now share the load.
Test4 - disable 0,4 (i.e. first physical processor). All other CPU's now share the load.
Test5 - Disable CPU 0 (i.e. first logical processor). All other CPU now share the load.
Test6 - repeat of test1 with exactly the same results!
Test5 is actually the scenario I wanted to use but I need to understand why this happens - any ideas very much appreciated.
Can anyone explain why the following happens?
Test1 - allow SQL to use all processors. CPU 0,2,4,6 show no performance. CPU 1,3,5,7 are heavily utilised. This equates to both logical processors on every second Xeon.
Test2 - disable 1,3,5,7. CPU 0,2,4,6 are now used heavily. Two Xeons are now disabled.
Test3 - disable 4,5,6,7 (i.e. all the second logical CPUs on each Xeon). CPU 0,1,2,3 are now share the load.
Test4 - disable 0,4 (i.e. first physical processor). All other CPU's now share the load.
Test5 - Disable CPU 0 (i.e. first logical processor). All other CPU now share the load.
Test6 - repeat of test1 with exactly the same results!
Test5 is actually the scenario I wanted to use but I need to understand why this happens - any ideas very much appreciated.