AI Denoise takes 45 minutes on new computer

Just for context, this is a rough guide to what you should realistically expect for Denoise processing times (actual time depends on the number of megapixels in the image):

• Recent laptop with pro-level graphics hardware and graphics memory: 15 to 30 seconds per image. 
• Recent laptop with decent consumer-level graphics: 30 to 90 seconds. 
• Recent computers with low-end/weak graphics hardware: 1 to 2 minutes. 
• Old computers or with low-end/weak graphics hardware: More than 5 minutes. 

So if I saw a time of 45 minutes (or even 15 minutes) for a new computer, I would definitely call that unacceptable. (My 3-year-old base level MacBook Pro with M1 Pro processor/graphics takes 35 to 70 seconds depending on the number of megapixels.)

There is not much the user can do to change the timing, in terms of application or system settings. The main one has been making sure the correct version of the graphics driver software is being used. For example, the driver software should be up to date, and if a gaming-optimized driver is being used, it should be replaced with a professional driver. If a new computer does Denoise slowly with an appropriate graphics driver, the computer should be exchanged for one with more powerful graphics hardware.

Note that the CPU and RAM aren’t major factors for Denoise, it’s all about the GPU. 

Newer graphics cards

Come on, don't leave us guessing ... specifically what graphics card?

You're using a Notebook and normally there's build in a CPU with an internal graphic processor. This can be reason for several issues. Try to disable the internal GPU.

To disable  use the Device Manager on Windows. In the Device Manager, right-click the card's name and choose Disable.