"jr" <cre### [at] gmailcom> wrote:
> Ash Holsenback <no### [at] spamcom> wrote:
> > On 9/18/20 7:22 AM, William F Pokorny wrote:
> > > On 9/18/20 6:36 AM, William F Pokorny wrote:
> > > ...
> > > and the cpu time jumps.
> > > ...
> fwiw, ...

no sleep.  :-(  so, if you (WFP)/anyone is interested, I can add to the ..
mystery.

I have the same alpha.10064268 installed on two machines, and I mean the same.
both built from the same tarball using nearly identical package build scripts.
on one machine, as posted, I see a decrease in time by (just) better than 50%
for the coloured background.  on the other, the alpha behaves as you describe,
time up from seconds to over a quarter of an hour.  wow.  I also tried two older
3.8.0-alphas (9893777 and 9945627) on a third box, they too run faster by around
50% when colour is used.  one thing I noticed is that where time decreases, on
the older boxes, the "CPU detected" reads "Intel,SSE2,AVX", whereas for the ..
misbehaving alpha (newer box) it's "Intel,SSE,AVX,AVX2,FMA3".  no idea whether
that is relevant, still, it'd be interesting to know what CPU flags others see.
anyway, as Kenneth intimated, computing, eh? -- all good fun.


regards, jr.

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