Can I combine two Mac Mini's for faster processing?

There had been pro users of scientific or mathematical purpose, whose business

or university (etc) research group had linked several PowerMac and later MacPro

models together; for specific purpose and within limits of program or application

these could do expanded computational work.

http://www.wolfram.com/solutions/industry/hpc/

an example of a professional solution source; ideas for 'parallel' computing.

The use of multiple Macs for specific purposes, can use software to share their

CPU over a network; such as astronomy to create a larger computer. But limited

by the bandwidth and connections between each, and their central processor.

You may do better by simply upgrading the drives, if they are 1TB rotational 5400-RPM

to SSD technologies and if the memory is also not fully maximized, install more. And

if you have quad-core i7 Mini Mac, all of the cores aren't necessarily working on one

project. There may be some way to maximize efficiency of multiple-core CPU, locally.

Once you do upgrade, you may need to consider better cooling; even to set the Mini

on its side allows more surface to be air-cooled passively. The server rack mount idea

is intended to allow extra localized supplemental cooling fans to be rid of excess heat.

Anyway, although I've read about this for quite some time, and at one point had an invite

to share my extra CPU with a scientific group, my bandwidth was very slow & costly; so

I chose to not participate. ~ Perhaps others who visit & contribute can offer better ideas.

Good luck & happy trails! 🙂

Some external rendering engines will let you do this, some are CPU specific, others use GPU. Some are proprietary and only use GPU's from one vendor and not another.

One of the After Affects/Premier designers here said he has done it in After Effects with Mercury having frames rendered on one computer and another set on another computer, but own use would be out of LuxRender and Cycles, neither of which run in Premier AFAIK

Software has to be specifically written to take advantage of clustering of multiple computer for extra performance. Adobe software is not written to do this.

Sadly even Apple's own APIs which might be suitable for this i.e. OpenCL also do not really support this. Apple have actually created at least two different clustering solutions in the past, Xgrid and Qmaster. Qmaster appears to have been discontinued when Final Cut Studio was replaced by Final Cut Pro X and Xgrid also appears to be dead. Whilst Qmaster never supported Adobe Premier it did use to support as mentioned Final Cut Studio and also several other third part tools. 😟

Other than swapping your Mac mini which remember is the lowest member of the Mac family for a more powerful one e.g. an iMac, your other option to consider is an eGPU approach. This involves putting a much more powerful video card in an external box and connecting it via Thunderbolt to a Mac. See https://bizon-tech.com/us/bizonbox2s-egpu.html/

I strongly suggest thoroughly checking with Bizon that this will work for your apps.

no, cluster processing only work for some network math processing tasks it does not make your computer Experince faster