Lens blur very slow and slow down my entire system

Lens Blur is particularly demanding, and especially demanding on the GPU. That means newer computers handle it much more easily. I’m not familiar with the Surface Book 3, but from some quick Internet searches, it looks like that is now a four year old laptop?

Also (again, I’m guessing from reading tech specs), Lens Blur will probably run better on a Surface Pro 3 with the Core i7 CPU and with Nvidia discrete graphics. But if you have a Surface Pro 3 with the Core i5 that has only the weak Intel Iris Plus integrated graphics, on that model I would expect Lens Blur and AI-related features to run relatively slowly. Both models only have 4-core CPUs; today’s laptops often have at least double that.

And this might not be the problem, but just in case…If your version of Lightroom Classic shows Lens Blur with the words “Early Access” in it, upgrade Lightroom Classic. Because the final release of Lens Blur runs much faster than when it was in Early Access testing. But still not fast. On my 2021 laptop with an 8-core CPU, decent GPU, and 32GB memory, Lens Blur still takes several seconds to calculate the initial result. I would expect Lens Blur to be faster on a PC or Mac made in the last couple of years. Because of how it works (having to calculate a depth map plus variable blur, manual refinements, and bokeh), it’s probably not a feature that can be made to run quickly on older computers.

My system is Laptop Microsoft Surface book3, 16GB RAM. Windows.

Please post your System Information as Lightroom Classic (LrC) reports it. In LrC click on Help, then System Info, then Copy. Paste that information into a reply. Please present all information from first line down to and including Plug-in Info. Info after Plug-in info can be cut out as that is just so much dead space to us non-Techs and it takes up vast amounts of scroll space making the reply less readable and less likely that others will bother with your post.