Re: CPU/cache detection wrong

Vojtech Pavlik
2002-10-01T16:56:54Z

On Tue, Oct 01, 2002 at 05:31:07PM +0200, Alexander Hoogerhuis wrote:
> Dave Jones <davej@codemonkey.org.uk> writes:
>
> > On Tue, Oct 01, 2002 at 09:21:26AM +0200, Alexander Hoogerhuis wrote:
> > > Here we go:
> > >
> > > CPU: Trace cache: 12K uops, L1 D cache: 8K
> > > CPU: L2 cache: 512K
> > >
> > > But my BIOS still say I should have 8Kb/8Kb I/D L1 cache... oh
> > > well. I'm sure Alan Cox would just write it up as marketing, since
> > > thats about how reliable a BIOS is :)
> >
> > Hmm, can a P4 have a trace cache AND an L1 I cache ?
> > I thought they were exclusive, which is why the code
> > doesn't take this into account. Easily fixed if so though..
> >
>
> I don't know the gory details of it, but my BIOS claims I got 8/8, but
> I'm deep enough in it now to start taking the 5th amendment on the
> details here :)

12k of trace cache and 8k of I-cache are more or less equivalent - trace
cache is less effective because it has decoded uops, while i-cache has
encoded instructions, which take up less space.

--
Vojtech Pavlik
SuSE Labs