Because I have been working on this problem for days, I thought it would be a good idea to post it on this forum, maybe I will help others with it? I have a fast PC: AMD Ryzen 9 9950X3D - 16 core 4.30gHz 64GB Ram 6400 and RME UCXII interface.
But still suffering from spikes and glitches and the fact that I had to keep the Latency Buffer size at least 128 samples, for larger projects with many vst’s. Not because that is such a big problem, but because I expect an expensive PC to do better. I have to admid I’m not very good with computers.
I read somewhere on the internet, that the AMD Adrenalin drivers (version 25.10.30.02) would be the cause of the many spikes and glitches, so I replaced them with version 26.6.1 WHQL. Not just the drivers, but the entire AMD Adrenalin package.
My GPU is the AMD Radeon RX7600.
After installing and adjusting all AMD Adrenalin settings for DAW use, the results were beyond expectations. The heaviest projects now ran on just 48 samples buffer size without a single hitch!
Then I was advised to reinstall the same AMD drivers, but not the entire package, but only the drivers, because that would be preferred by many producers and would be even better? However, it wasn’t true. After installing just the drivers, and following the AI advice to check the box: ‘factory reset’ when installing, the spikes and glitches turned out to be back and I had to go back to at least 128 samples to be able to work a bit.
So I loaded the entire AMD Adrenalin package for the second time, then turned off all graphics and game options, and everything was completely fine again. Do what you want with it, I don’t know the cause, but the AI advice was wrong.
Perhaps installing with “reset all to factory” settings checked is the cause ? I don;t know what these factory settings are of course, but I wonder: How can installation of a complete package (albeit with adjusted settings for audio instead of games) be so much faster than the same package, but only the drivers?
That’s because it isn’t advice, it’s just a summary of stuff found on the internet, nicely formatted.
On my latest build, with an NVIDIA GPU, if I don’t also install the HD Audio driver from the package, I get more spikes. I am guessing that a stock HD Audio driver from Windows then gets installed, and somehow does not play well with the GPU driver – I don’t know, but I just do the “simple” install now.
NVIDIA provide a “studio” driver which is better than the game-oriented one, does AMD provide anything like that for their own GPUs?
The AMD GPU has “Adrenalin” and three installation options: minimal, full update, or just the drivers.
You also have the option to ‘restore factory settings’.
However, I do not know what those factory settings are, but they are likely based on average usage and not specifically on Audio DAW usage.
And that is probably the reason why installing the entire package and then customizing it yourself yields a better result for Cubase. However, I have not tried the minimal installation.
I run my AMD without any of the Adrenalin software, just the drivers. I’ve also avoided tinkering with the BIOS (other than turning off the infuriating LEDs!).
My new PC a couple of years ago had all sorts of latency issues, and it was built specifically for audio by a company. Unfortunately it can take a while to get to the bottom of the issues. You don’t mention your GPU - anything other than a basic built-in interface is essential in my experience. I had problems that the fast memory specified was ‘too fast’ for the SSD. Another thing I eventually figured out.
Start with the GPU - which one to you have?
The OP did …
My Bad! Not paying enough attention!
Hmmm … in that case we can discount the graphics card being at fault. SSD Speed? Any non-standard installation locations for Cubase?
Also no, as the problem goes away with different installations of the same graphics driver:
@ manassas77: My SSD’s are WD SN8100’s speed is 14,900MB/s that should be fast enough? 
I loaded the AMD cleanup utility, removed the complete amd installation,
And installed the program again,( this time with the minimum installation.) everythings fine now. I deliberately did not opt for the “drivers only” version, but for the “minimal” version because I want to be able to see what the settings are and - because ( in my case) it turned out that the minimal version requires less CPU. Thank you everyone for your input. I really appreciate it !
Good news you got it sorted!