From what Adobe suggests for their CC minimum specifications in OS X, there
should be no need to buy a quad-core (they don't say it would use all cores.)
One set of Photoshop CC system requirements suggest higher specs than a
different Help page from Adobe. This page shows the higher specs but may
not reflect the version you are considering:
•Photoshop CC 2015.x system requirements and language versions
https://helpx.adobe.com/photoshop/system-requirements.html
If for some reason you happen across a Late 2012 i7 2.3 or 2.6GHz quad with
dual 1-TB hard drives, they would be most easily upgrade to run an SSD and
keep a rotational drive; or install two SSDs. Between that & 16GB RAM, those
should make a quick little computer. The rotational HDDs are the bottleneck.
But probably not necessary for Adobe photoshop CC. The Graphics processor
is a limitation, if you are using graphic intense applications. The GPU shares
standard memory with the system; there is little/no dedicated graphic memory.
While I have a Late 2012 Mac Mini i7 2.3GHz quad-core (server) with dual 1-TB
rotational 5400-RPM hard disk drives, and upgraded RAM to 16 GB total. It can
use at least one drive upgraded to 7200-RPM or a more efficient solid state drive.
The Mac Mini that's in the online store (check to see if any official refurb exist)
in the middle to higher spec version may be OK. The upper level given upgrade
options in the configuration page (select as if to buy, then see what options exist)
could be OK. The lowest spec Mini does not appear to be viable for serious users.
Due to the builds available now, new, you have to choose the configuration when
you order the computer: you buy an upgrade level you think you may need.
The memory is affixed, so exercise your ESP skills to look ahead, before buying.
The newer Mac Mini 'upper model' has better graphics than Late 2012 model.
An advantage to the Mini is you can choose displays, peripherals, etc. An old
new-stock Mini would have whatever OS X that was current, as base level.
Since none of these units have backup system media. Online recovery is it.
My Mini shipped with Mavericks 10.9; it runs 10.9.5 adequately. Partitioned,
the drive(s) could dual boot mulitple systems & their newer spec applications.
(You can pay like-new prices for the Late 2012 Mini i7 quad, in clean used form.)
I'd considered a non-Retina MacBook Pro 13-inch 2.5GHz for a time.
that was back when they were more common in Apple 'special deals'
refurb page in online Store at OK price; then buy upgrade RAM later.
Anyway, this became a lengthy diatribe of which a few details or detours were
omitted for sake of clearing the path back to main topic. Since I have the Late
2012 Mac Mini and it's more than halfway upgraded to do most anything it can
I'd probably have to say try one. If you can find an as-new at fair cost.
If the cost it too high, you may as well get a new Mac Mini of highest spec from
the Apple Store. They are dual-core. Adobe applications do not appear to need
or advantage from use of quad-core processors. (these run virtual cores, too;
so if one has the appropriate application, the quad core runs eight - virtual.)
The AppleCare option to extend the warranty is reason to buy new hardware.
It would ship with El Capitan, if current new stock. This fall, it may have macOS
Sierra - if you happen to get that new of stock - by the end of the year. Not sure
if or when any hardware upgrade version configurations may appear.
So anyway, this looks more and more like some kind of letter. Sorry about that...! 😝
