Is there anything I can do to my 2013 Mac Pro (3.5 GHz 6-Core Xenon E5 32GB RAM AMD FirePro D700 6144MB) to better handle 4K natively? Sometimes I don't have time to render proxies, and I can't get a new computer at the moment, but I do have budget to do upgrades. Any suggestions?
That machine should be fine. I run the 8-core/64GB RAM/D500. What storage system are you using and how is it connected? What camera/codecs? Which version of Premiere? Odds are it's Premiere, which tends not handle 4K as well FCPX.
Premiere Pro 13.0. 4K footage from a Canon C200 (Cinema Raw Light .CRM) and H.264 from an Osmo Pocket. Main storage is on a ProMax network system (10GB ethernet), cache on a local RAID drive. Files from the Canon not so much of an issue, since I can record proxies in the camera, but other 4K sources lag significantly on playback or scrubbing.
My gut feeling is that the 10Gig RAID is not what you want to do, to start with. I would really think you'd have better luck with a Thunderbolt RAID, like a Promise Pegasus. Secondly, those codecs are very poor with Premiere, especially the H264 from the Osmo. It's unbelievably awful.
Your best bet is proxy/full-res - or better yet, transcode the footage to ProRes first before ever editing. If you transcode ahead of time, either use Adobe Media Encoder or Resolve. The latter is probably your fastest. The one downside is that the GPU design on the trash can Macs is a huge Apple misstep. I have the D500s and constantly get glitches with heavy-duty rendering in all, except Apple apps. That's because none of the other manufacturers balance the load correctly between the two GPUs and therefore one overheats. I've added a utility app to run the fan speed at max all the time. It mitigates the issue, but doesn't solve it.
Premiere also does worse when you have a mixed set of codecs. If it were all 4K ProRes, for example, instead of mixed, then your performance would be better. Also 4K in a 4K timeline might have better performance than 4K in a 1080 timeline, since no extra scaling is required.
You might also want to play around with OpenCL versus Metal GPU acceleration. Good luck. HTH.
The H.264 would be much better handled by almost any current Mac other than the Mac Pro. The laptops, iMacs, and new Mini all have built in acceleration for H.264 decoding that works very well. There is nothing you can do to the trashcan Mac Pro other than replace it with a better machine (i.e., find a 12 core rather than the 6 core). But even if you do that, you still won't have either the H.264 acceleration or Thunderbolt 3 that you get with every other model they currently make.