Just got iMac Pro with "Radeon Pro Vega 56 8 GB" and 32GB Ram. Less performance than expected Ideas?

[jreichstadt]

I just got a 2017 iMac Pro with "3.2 GHz Intel Xeon W" Processor and "Radeon Pro Vega 56 8 GB" GPU with 32GB Ram ( non-upgradable ) .   I call this computer "JP4"

My other computer is a 2017 iMac with the "4.2 GHz Intel Core i7" and "Radeon Pro 580 8 GB" 64GB Ram.  I call it "JP2"

I had hoped that "JP4" would outperform "JP2" with render times of around 55% based on a quick benchmark test I performed back in late December 2019 against a similar iMac Pro.  That must have been in one of the 2019 versions of Premiere Pro but Im confident that the iMac Pro at the time was out performing "JP2".  

But now this iMac Pro I just acquired "JP4" is running anywhere from 20 to 50% slower than my Non-Pro iMac "JP2".  It seems like Adobe Media Encoder is just not running as fast in either the CPU or the GPU when processing Adobe Premiere Pro projects.  The project is in Premiere Pro version 14.4.0.

When running a "Unsharp Mask" in fact the "JP2" computer indicates about 191% CPU and about 45% GPU.  the "JP4" iMac Pro shows 190% CPU and ZERO GPU.  

Does anyone know a solution to this or would I be better off selling this iMac Pro for the $3400 I can get for it on Ebay and buying another one like my "JP2" machine and have $1200 left over to buy hand sanitzer and toilet paper to hoard?

I've been scrounging around hoping to find a helpful thread but not really finding a clear answer except that maybe the 8 Cores in the "Xeon W" processor just won't be as effectively utilized as the 4 Cores in my "4.2 GHz Intel Core i7 and 4.2 GHz is just faster than 3.2.... 

Anyone know how I can boost the usage of the GPU on this iMac Pro?

[Kasper Garam]

Hey there! I know this is an old post, but I have a very similar iMac Pro compared to your "JP4" and I am not happy with the performance of it. Did you ever come up with any solutions to this? Did you get the computuer working faster?

[Warren Heaton]

The rule of them for video editing is fewer, faster cores.  So, the 4.2 GHz iMac should beat the 3.2 GHs iMac Pro for most video editing tasks.

However, now that After Effects has Multi-frame Rendering (MFR) that's supported in Media Encoder, anything from After Effects as long as MFR is not disabled by the user should be noticeably faster with the iMac Pro.

For 3D though, the iMac Pro should show better performance.

The best thing for both machines is using ProRes for everything.  For very fast peformance transcode source to ProRes if it isn't already;  edit ProRes;  finish ProRes.  Delivery to other formats only if needed.  

For more, detailed info, read Hardware recommendations for Premiere Pro and After Effects.