I'm currently developing my own graphics engine and decided to try it out on other graphics cards. I'm developing it on an AMD graphics card where it works perfectly fine. But on my friends NVidia card it went completely crazy.
Since I'm using a deferred renderer I decided to just clip materials where the transparency is below 0.5f. I decided not to implement actual transparent materials since deferred renderers don't really support them (even though I'll probably come up with a solution sometime later in the development).
But the clip() instrinsic completely randomly clips pixels away on his graphics card. It even clips entirely different pixels each frame.

Here's how it looks like:


And here's the code (reduced to what's important):
[source lang="cpp"]PSOut PSMain(PSIn Input)
{
PSOut Output;

float4 albedo = AlbedoTexture.Sample(Linear, input.Texcoord);
clip(albedo.a - 0.5f);

Output.Albedo = albedo;

return Output;
}[/source]

I'll probably solve it by using Alpha Blending with just the values 0 and 1. But I'm just interested in why this might be happening and if there's still a way to use the clip() instrinsic.