topic Re: Severe Zoom Lag / CPU Spikes in Large Projects – RTX A4000 Not Used Properly? Archicad 28 in Installation & update

Severe Zoom Lag / CPU Spikes in Large Projects – RTX A4000 Not Used Properly? Archicad 28

tashkoff — Fri, 21 Nov 2025 09:18:32 GMT

Hello,
I am experiencing a serious performance issue with Archicad when working on a large project (over 100,000 elements/points). I would like to report the problem in detail and request assistance.
My system configuration:
CPU: AMD Ryzen 9 9950X3D
RAM: 128GB DDR5 6400MHz
GPU: NVIDIA RTX4000 ADA Gen 20GB GDDR6 PCIe 4.0-Active Coolin Storage
Samsung 990 PRO NVMe SSD
OS: Windows 11
Drivers: All drivers are updated to the latest versions (NVIDIA Studio Driver, chipset, BIOS, etc.)
I have manually set Archicad to run on the dedicated GPU (RTX A4000) through the NVIDIA Control Panel (Program Settings → Archicad.exe → OpenGL Rendering GPU → RTX A4000, Prefer Maximum Performance).
Despite this, I am still experiencing the issue.

Description of the problem:
When I open a large project and start zooming or navigating inside the 2D/3D window, Archicad starts freezing and the Windows loading circle appears (as if the system is thinking).
The application becomes unresponsive for several seconds, then works normally for a moment, and then freezes again when I zoom or move.
This cycle repeats constantly and makes it practically impossible to work on the project.
The issue occurs in:
Archicad 28 (build 3001 INT FULL)
Archicad 25 (latest update)
So the version does not seem to be the cause.

What I have already tried:
Reinstalled the latest NVIDIA Studio Driver
Clean driver install (DDU)
Forced Archicad to use RTX A4000
Updated BIOS, chipset, Windows
Tried both Archicad 28 and Archicad 25
Reset Work Environment

Re: Severe Zoom Lag / CPU Spikes in Large Projects – RTX A4000 Not Used Properly? Archicad 28

Akos Somorjai — Fri, 21 Nov 2025 08:40:44 GMT

Hi,

Thanks for reporting the issue! This is better suited to the normal technical support channel, or as a post to the https://community.graphisoft.com/t5/International/ct-p/EN Archicad part of the community..

Best, Akos

Re: Severe Zoom Lag / CPU Spikes in Large Projects – RTX A4000 Not Used Properly? Archicad 28

danielk — Wed, 26 Nov 2025 11:13:22 GMT

Hi there,

Have you managed to solve this yet? I have a similar setup and I also feel like it is more sluggish than it is ought to be.

Re: Severe Zoom Lag / CPU Spikes in Large Projects – RTX A4000 Not Used Properly? Archicad 28

tashkoff — Thu, 27 Nov 2025 10:30:33 GMT

Yes, i think so. Pay attention to:

In Archicad:

Power Management Mode → Prefer Maximum Performance

Low-Latency Mode → OFF

Threaded Optimization → ON

Vertical Sync → OFF

OpenGL Rendering GPU → RTX A4000 (or yors Graphic card)

In Windows:

Good luck!

Re: Severe Zoom Lag / CPU Spikes in Large Projects – RTX A4000 Not Used Properly? Archicad 28

Barry Kelly — Fri, 28 Nov 2025 00:48:48 GMT

I am having issues where Archicad (in fact my whole computer) freezes for 15-20 seconds.

I work mainly in version 22 & 25, but I sometimes have 28 or 29 open at the same time for testing.

I seem to only have this issue when 28 or 29 is open.

I am wondering if it is the floating cloud license that 28/29 uses?

Are others with this problem using floating cloud license or is the cloud license allocated to a user?

Or is it still a perpetual hardware/software license?

For me the pause happens every five/ten minutes or so.

It doesn't seem to be when I do a particular task like zooming.

The blue 'thinking' circle comes up and the entire system does not respond.

It does seem to remember the commands you do while it is there as it tries to complete them when the circle goes away.

If I close 28/29 the issue goes away.

It seems to be only since the last updates as I have not noticed this until recently.

I need to do further testing before I report this to support.

Try a different machine.

Switch to an allocated user license.

Maybe downgrade the lates updates.

Just wondering what sort of license you are using?

And is your 28/29 up to date with the latest updates?

Barry.

Re: Severe Zoom Lag / CPU Spikes in Large Projects – RTX A4000 Not Used Properly? Archicad 28

Barry Kelly — Mon, 01 Dec 2025 05:17:25 GMT

Still trying to narrow it down.

But working on another machine with 28 running (not the latest update) had no freezes at all.

Working on my office machine today with 29 running (initial build 3000), and it is pausing, but not as often as before.

I have change my cloud license from floating to named.

Not sure if that made some difference, but I am still getting an occasional freeze for about 30 seconds, just not as often as before.

Barry.

Re: Severe Zoom Lag / CPU Spikes in Large Projects – RTX A4000 Not Used Properly? Archicad 28

Barry Kelly — Mon, 01 Dec 2025 07:39:44 GMT

I turned 29 off and worked for 3 hours with no freezes.

Just turned it back on (not actually using it), and within 30 minutes had a freeze.

My suspicion is turning to the cloud license, although I am sure it was fine with 28 before I upgraded.

Next step is to re-install 28 and try without upgrades.

That will be in a couple of days though, can't do it straight away.

Barry.