Hi,
Any performance bottleneck if HT (Hyper Threading) is enabled in quad core processors on CentOS 5.8 running MySQL DB Server ? Please help me understand about pros and cons of this feature.
Regards,
Kaushal
on 4/12/2012 5:57 AM Kaushal Shriyan spake the following:
Hi,
Any performance bottleneck if HT (Hyper Threading) is enabled in quad core processors on CentOS 5.8 running MySQL DB Server ? Please help me understand about pros and cons of this feature.
Regards,
Kaushal
As far as I know, hyper-threading is sort of like processor emulation... As long as the extra threads are hitting different registers, it can help. But if it needs any floating point, the thread will wait until it has full access... It seems to be hit or miss on how much it will hurt/help a load...
On 04/12/12 1:06 PM, Scott Silva wrote:
As far as I know, hyper-threading is sort of like processor emulation... As long as the extra threads are hitting different registers, it can help. But if it needs any floating point, the thread will wait until it has full access... It seems to be hit or miss on how much it will hurt/help a load...
database work is almost never floating point bound, even if the SQL is full of FP code, for every FP machine operation there's 1000s of integer operations, for which the HT does quite well at.
HT is almost always a win-win on everything that can use lots of threads, other than scientific processing or multimedia encoding (video transcoding etc)
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John R Pierce -
Kaushal Shriyan -
Scott Silva