Jhoravi wrote:Is there really a need to dissable HT? How about just set it half the total number of logical cores and leave the utilization handling to Windows 7?
There is no need to disable HT (in the BIOS).
Disabling HT turns an i7 into an i5.
FYI an i7 3930 k has 6 Physical Cores and an i5 only 4 Physical Cores.
Turning on HT in i7 has the effect of CPUID-CPU-Z showing that 12 cores are running ( 6 physical and 6 virtual).
Turning off HT in the i7 3930k results in only the 6 physical cores being shown, which is still more than the 4 physical cores of the i5.
So, Disabling HT does NOT turn an i7 into an i5, (unless of course you are talking about the i7 2500K or the i7 2600k which have only 4 cores ).
Hope I've made myself clear.
Jhoravi wrote:Is there really a need to dissable HT? How about just set it half the total number of logical cores and leave the utilization handling to Windows 7?
Jhoravi wrote:I agree. If you have Core-i7, just leave Hyperthreading ON and run chess according to Core-i5 rules.
Are you delusional?
Can you atleast explain the drawback of using only half the Virtual Cores while Hyperthreading ON? I always thought the OS will properly distribute the loads to the physical cores in that setup.
imo there may be a very slight performance boost but if its not a dedicated chess computer it would come at the expense of convenience and likely, performance hit w/ multitasking.
when the i7 first dropped it was suggested by either vas or lukas cimotti (sp) that the optimal setting for rybka on a quad was HT on with affinities set to cores 0,2,4 & 6. i tried this experiment with houdini 3, 1GH hash from start position, cleared each run:
seems like there may be a slight speedup. again probably not worth the mouseclicks if it's not going to be solely dedicated to chess for a long period.