Single-thread performance: iMac Pro vs. iMac

I’m kind of getting the iMac bug, ostensibly to process my neuroimaging data.
In thinking about whether to go with a regular iMac, or drop another $1300 for the Pro, it seems that any single-threaded applications would run faster on the regular iMac, since its processor speed is higher than the iMac Pro. A Geekbench comparison confirms this, but I wonder what it’s like in real life?

IMac: 4.2GHz (4.5GHz turbo), 32GB, 1TB SSD, $3699, GB 5679

Pro : 3.2GHz (4.2GHz turbo), 32GB2 1TB SSD, $4999, GB 5040

Having used both the high-end 5K and now the base model iMac Pro, I can tell you the biggest differences come in multi-threaded work. If you can parallelize that work, the Pro will smoke the regular iMac.

The other big difference is the cooling. I hardly ever hear the iMac Pro’s fans, while the 5K can sound like a lawn mower under heavy, sustained loads. Remember too that the iMac Pro’s storage is a good bit faster, if that’s a concern with your workload.

The iMac is due for a CPU bump, which may change some of this math, of course. I’d maybe say spend the $1300 to future-proof, but the speed difference between the two in single-threaded tasks probably isn’t super noticeable in the real world.


Thanks for your insights.
I hadn’t thought about disk read/write speed. Good to know.