[vox-tech] Debian configuration: X and modem and zip]

[Peter Jay Salzman]

On Sat 24 Jul 04,  9:02 AM, Jonathan Stickel <jjstickel at sbcglobal.net> said:
> Mark K. Kim wrote:
> >On Fri, 23 Jul 2004, Ashleigh Smythe wrote:
> >
> >
> >>I managed to install and activate a later kernel from my woody CD as
> >>you suggested Rick, and now uname -r shows that I am running kernel
> >>2.4.18-686-smp (I wasn't really sure which of the pentium IV 2.4
> >>kernels to choose so I took a shot on that one).  Nothing seems to
> >>have changed with respect to the video card or modem - tried various
> >>combinations of things in the dpkg-reconfigure xserver-x86 tool for
> >>the video card problem and have run pppconfig also to no avail.
> >
> >
> >Any kernel that ends in "-smp" is for computers with more than one CPU
> >inside the system unit.  This is probably NOT the version you want...
> 
> Maybe, maybe not.  I've "heard" that P4s with hyperthreading need an smp 
> kernel to actually use the hyperthreading.

this is true.  hyperthreading requires the same type of locking
mechanisms that SMP does.  in particular, you need spinlocks in places
where you normally don't need them for UP.

> However, my wife tried an smp kernel on her work P4 with HT, and it
> didn't seem to change anything.  Take home message fore me:  buy AMD64
> if you want top performance in Linux.
> 
> Jonathan

just because you don't SEE a difference doesn't mean the difference
isn't there.  :)

everyone knows you don't get a 2:1 performance increase with SMPx2.  and
SMP doesn't scale linearly, either.  and you're not going to get it with
HT, either.  i don't follow HT (i'm strictly an AMD guy), but it's my
understanding that an application needs to utilize HT for any
appreciable gains.  it's not simply a matter of an application being CPU
intensive or not.

as far as linux support, it's my understanding that the kernel had HT
support even before the HT specs were officially released.

that said, i totally agree with your conclusion.    :-)

pete

-- 
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