Gigapixel very slow on iMac 2019


Try to work with the latest version of Gigapixel on my iMac 2019 i5 3.7gig
Graphics card: AMD Radeon Pro 580X Open Gl
CPU ram: 40gig
GPU ram: 2047 total in use 2047
Preview limit: 4492px

Unfortunately is takes ages to do an image JPG from 5000px to 10000px !
No matter if I use CPU or GPU and any adjustment in the preferences!

On my laptop (Windows 10 with an Nvidia card) it go’s 10 times faster.

What I don’t get is that the graphic card in my iMac is 8gig, but I don’t see that back in the Graphics Info panel!?

Regards & Thanks,


David, please raise a support request at the Topaz Labs main website.

Thanks Don,

Did raise a support request and the only advice I got was a fresh install after reboot that unfortunately does nothing.

I experience the same problem with: Adjust AI and Sharpen AI.

For the moment I’m back to the old Adjust and get faster and better results with much more control over detail. Till now I’m not impressed at all with the AI plugins I have, including the latest Mask AI.

AI means nothing to me when the results are not good and the workflow 300% slower.



David, when you get a chance can you quickly post the info from the Help- Graphics info menu. Just need to press copy and paste it here. Very strange …


Hi Don,

iMac 2019 i5 3.7 gig

40 gig internal mem

Application & Version: Topaz Sharpen AI Version 1.4.3

Operating System: macOS Mojave (10.14)

Graphics Hardware: AMD Radeon Pro 580X OpenGL Engine

OpenGL Driver: 4.1 ATI-2.11.20

CPU RAM: 40960 MB

Video RAM: 2047 MB Total, 2047 MB In Use

Preview Limit: 4492 Pixels

Just got an message from “Topaz Operations”:

I’ve noticed on several support tickets that this particular graphics card has been involved in some slowness complaints, and have confirmed with two developers (independently), that the Radeon 580 is apparently known for not operating as expected. It seems to be a flaw in that particular card/driver combination that is known among software engineers. In particular they referenced that it would show it was using full VRAM but in reality was using a fraction of it.

That being said we have an Open GL related update coming that is related to some errant crashing on some machines running Gigapixel AI and Sharpen AI, so it’s probably worth seeing if it affects you as well. We are trying to release that update this week.

If you can hang tight for that update, I think that’s the best next step to see if we can find a resolution for you.

How is it possible that this 8 gig graphics card only shows 4 gig and uses 2 gig of it!?

Only thing now is that my Demo from Sharpen AI is halfway expired and I could hardly test it.

Regards & Thanks,


Hi David, hopefully the update to come will solve the issues. You will need to ask for an extension to your trial at the main website as you need to ask for any other issues concerning updates etc.

I see on the Apple forum there are complaints about the AMD 4/5 series but not all blame OSX.

Why it only reports 4GB only Topaz can answer as even on Windows the wrong version of OpenGL is reported but that may be because it users that version.


I have a RX 580 GPU with 4GB of Vram on a Windows 10 machine. I noticed today that gigapixel was running slow so I check the Radeon settings. It seems that the video card was stuck in a slow mode 300MHz for GPU and a 300MHz for the memory (usually can go to 2000 MHz). I ran gigapixel and the frequencies stayed low.
I loaded a saved profile and everything came up to normal and this greatly sped up the processing in gigapixel. I wonder if you have looked at the Radeon settings > Gaming > global settings > Global wattman to see if the memory and GPU are going to max speed when needed?