2017 iMac i7 4.2ghz vs iMac pro xeon w 3ghz?

[lancegilliland]

I am looking to upgrade from my 2012 MacBook pro to a desktop machine for lightroom and photoshop photo processing, and possibly at some point minor video processing.  Any know which of the above machines would perform better, putting aside cost which i realize is not trivial.  more detail on the machines i am considering:

iMac 4.2ghz quad core i7 turbo to 4.5ghz, radeon pro 580 8gb gpu

vs

iMac pro 3ghz 10 core xeon W turbo to 4.5ghz, radeon pro vega 56 8gb gpu

Most of my work is processing 36 megapixel raw photos in lightroom and photoshop, so that is where i am looking for dramatic improvement.  I have read that lightroom and photoshop do not make much use of multiple cores, particularly beyond 4 or 6, and that clock speed is more important? 

any help greatly appreciated!

[Just Shoot Me · Accepted solution]

If I read all the reports and reviews properly on the new iMac Pro systems they are more geared to Video editing.

Working with still images you probably won't see much speed increase from the non pro to the pro system.

Also LR has a problem with CPUs that have more than 4 cores. That may be fixed in future releases but who knows.

If money is really no object go for the biggest and fastest system you can.

Personally if I was thinking about buying back into the Apple world I'd wait for the supposed new Mac Pro systems coming in mid 2018.

[Jao vdL]

I would guess the iMac Pro will probably win hands down. Its more the much more beefy graphics card and the enormous bandwidth to CPU and main memory that will make a difference here that Xeons are much better at than i7 cpus. Photoshop strongly benefits from multiple cores in many actions also. Also recent versions of Lightroom are multithreaded much better than before. There are many reports now on the Mac Pro that it is very good at Lightroom and Photoshop work.

If you are close to an Apple store I would just go and check it out. They will let you run stuff on the machines for this sort of decision.