On Sat, Dec 31, 2005 at 03:30:29PM +0100, Niek Bouman wrote: > Hi, > > I have a pc with a pentium4 cpu with HT support running FreeBSD 6-STABLE. > > In the GENERIC kernel, SMP is turned off by default. I am wondering > whether it is useful to enable HT-support. > > In the usenet discussions, I have seen a lot about the HT security flaw > that was detected a while ago. Also I read about some rumours saying > that the system performance decreases with HT enabled in freebsd, > because freebsd thinks that there are 2 physical cpu's and adapts the > workload over them in a way that is not suitable for just one physical > HT processor. > > Could someone give advice on whether it's wise to enable HT-support in > 6-STABLE? > > And, is the following correct: enabling SMP (=HT in this case?) is > nothing more than adding "options SMP" to the kernel config file and > then do a kernel rebuild & reinstall ? > > And what about the scheduler? Is the usage of ULE recommended, or should > i stick the old one?
These questions are answered all the time, but the answer is that HT usually hurts performance, and so does ULE. Kris
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