Archived from groups: comp.sys.ibm.pc.hardware.chips (
More info?)
On Tue, 10 May 2005 08:31:26 -0400, Yousuf Khan <bbbl67@ezrs.com>
wrote:
>Interestingly, I was listening to a podcast on Zdnet the other day, and
>they were interviewing a Windows XP Embedded programmer. He said his
>application runs on VIA chips because they don't want any moving
>mechanical parts in their computer systems whatsoever, not even hard
>drives or fans.
Not at all surprising, the failure rate on those components tends to
be significantly higher than for solid state components, especially if
you operating in some less-than-ideal environments.
> One interesting thing he noted about the VIA chips is
>that they seem to spread their workload over much more smoothly. He
>compared it against an old P3, and said that you'll see the CPU meter
>will show long idle periods followed huge spikes in the P3, but for some
>reason the VIA C3 seem to have a constant amount of workload but hardly
>any peaks. Perhaps the instruction timings are different on the C3's
>therefore programs which rely on instruction timing don't get their
>expected values on C3's?
The VIA C3 is a mostly (completely?) in-order processor, so while this
hurts it's performance a bit, it does tend to make the chip a bit more
predictable and steady. With the P3 you're looking at an out-of-order
processor. This may result in more idle periods where the processor
is waiting for data from main memory and then periods of higher peaks
where the chip is able to run more instructions at once.
Of course the other, and much simpler, explanations is simply that the
P3 does all it's work much more quickly than the C3. Where the C3 is
constantly having to work at a steady pace just to keep up, the PIII
can simply zip through the work and then sits around waiting for the
next batch to come through.
Either way, it really shouldn't matter much since it's really the
maximum power consumption that counts more than anything else. It's
not like WinXP Embedded is a Real-Time OS, so it doesn't make much
sense to put timing constraints on your processing. The difference
between the chips is a bit interesting, but probably not all that
important.
-------------
Tony Hill
hilla <underscore> 20 <at> yahoo <dot> ca