HTT on Atom (Was: FreeBSD 8.0 and Atheros AzureWave wireless chipset)

[Brett Glass]

At 04:33 PM 11/26/2009, Manolis Kiagias wrote:

>Though it seems hyperthreading is improved on the Atom and there is no
>penalty for leaving it on.

Is there really no penalty? With HZ=1000 there are double the clock 
interrupts to be serviced at least. And as I understand it the Atom 
has less redundant hardware, so there are less likely to be unused 
resources available to the second thread. I am seeing substantially 
faster compiles with the SMP option commented out of the kernel.

--Brett