On 9/15/2015 9:26 PM, Mayayana wrote:
Multiple cores can only be used for multiple
threads/processes. If you want to print while
using PS then a second core is nice. You may
also be able to do two things at once in PS.
But even that seems a stretch. If you do something
like apply a filter to a very large image, that's a
single operation. It can only run on one core. And
what else are youy going to do concurrently?

I imagine that's what Chris Cox is talking about.
PS can use the cores if you're demanding functionality
from multiple threads/processes at the same time,
but for one intensive operation, multiple cores will
be slower because each core is slower than the total.

On XP I use 2-core because I don't think XP
can optimally use more. Win7+ is probably
better, but optimization still means having uses for
those cores. Since I'm rarely doing more than two
things at once, I'd rather have two operations
running at 1800 MHz than have 4 cores running
at 900 MHz each, but with only one or two used.

If you're running clean, it's unlikely you'll see
much benefit from more cores, and Intel vs
AMD shouldn't matter. (Though specific CPU
models get different ratings.) In other words,
if you have PS applying a sharpen to a giant
image, maybe it takes 30 seconds, but what
else are you going to have PS do at the same
time that could increase efficiency? Not much.

The only scenario that makes sense to me for
more cores would be a system weighted down
with AV, malware hunters, excessive services,
etc. If you have 4 cores you might be able to
use them all with so much crap running, where
two cores might be forced to allocate time slices
to multiple processes, thus being slightly less
efficient. But aside from servers, it's hard for me
to see the benefit of a large number of cores.
It just means that each core is running slower.

You can research this yourself. Run Task Manager
and then use PS as usual. You'll probably find that
a demanding operation is using 50%, 25%, etc of
the CPU, depending on how many cores you have.
(2 cores -- max intesity is 50% of CPU. 4 cores --
max intensity is 25% of CPU. Etc.)
Is another process or another PS operation maxing
out another core? If your cores are not being used
then the increase in cores is just slowing down your
machine.



Thanks, sounds like good information. Since I am doing pre-purchase
research, I will not be doing the experiments. I am thinking quad core
with about a 3.5 - 3.8 CPU. I know there are faster, but I am not yet
convinced that the additional price is worth the extra cost.

--
PeterN