I just finished an installation of 6.3 on a P4-2.6hgz system that runs with hyperthreading just fine when I boot windowsXP or LINUX. In the GUI login screen it is showing only 1 CPU.
I’m not sure if this means I’m not getting hyperthreading, or that its identifying one physical CPU, but really has two logical CPU’s a la hyperthreading.
Is there something special I must do to get hyperthreading working, or to check whether it is active or not?
Are you sure that you are running SMP qnx kernel ?
I dont know how in 6.3, but in 6.2.1 was uniprocessor kernel installed by default
How would I tell it to change to a hyperthreading kernel?
cp /.boot /.altboot
cp /boot/fs/qnxbasesmp.ifs /.boot
reboot
Yup, it worked! Many thanks!
There is no such thing as hyperthreading kernel, only SMP kernel. QNX will think there is 2 CPU. This may not be a good thing. 2 CPU and hyperthreading do not behave the same. You should benchmark you stuff, cause you could actually get a decrease in performance (which is the case even in Windows and Linux)
My use of “hyperthreading” was for clarity, hoping to avoid some intermediate explanations that would only complicate my question (yes, I understand the difference between logical and physical cpus, SMP and non-SMP kernels).
I did get the SMP kernel working and I succeeded in running the benchmark that originally lead me to test QNX. With the SMP kernel I am finding it runs the benchmark about 200 usec faster than in the non-SMP kernel, so SMP is definitely the way to go for my needs.