Although the new GeForce RTX 5090 FE graphics board packs a massive amount of compute horsepower, its ‘main’ PCB is really small card compared to the GeForce RTX 4090 (pictured below).

V-grooves that go most of the way through a PCB are one way to go about this, but a line of perforations along which to snap a tab is another. But what’s the best size and spacing of holes to use?