HZ=100 ?? vmware
jason
jason at ec.rr.com
Thu Oct 14 13:23:43 PDT 2004
dick hoogendijk wrote:
>Okey, I found out I need to increase the HZ=100 default in the kernel
>config to a higher number. I also understand it decreases system
>response times.
>
>So, what I need to know is the lowest setup for HZ=??? to be able to run
>vmware3 in full screen. I got to get rid of the "rtc: 100 > kern.hz"
>prompt.
>
>Google tells me to increase to HZ=1200 but is this not too high?
>
>
>
In man polling a kernel config of HZ=1000 is the default if you want to
use polling. I am not sure, but if vmware is using the same HZ setting
as polling does then 1200 is not too high. If I understand it right,
the HZ setting tells stuff how often to checkin to see if work needs
doing. 100hz would be way too low. Every 100hz on say a 2ghz machince
would requirer you to spend a lot of time on something every
sec(2billion/100 per sec if I am right). Maybe nothing because you are
delaying some programs that you want to execute, not pause and wait
every 100hz. This would most likely slow everything down, a higher
number would make things smoother and faster, but only to a point. Its
kind of complicated, but when you find the right spot(somewhere in the
middle) everything is good. If you had a 4ghz machince you may want an
even larger number. If I am wrong I am sure there will be a followup
shortly.
Jason
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