https://developer.apple.com/forums/thread/820929

It appears the memory consumption was due to the Shader and API Validation I had enabled in my scheme. Once I disabled these, memory use went back down to normal.

[quote='871886022, pbantolas, /thread/812419?answerId=871886022#871886022, /profile/pbantolas'] That's my guess, worth adding a reset at the end to see if it fixes it. Still sounds like a bug so consider reporting it! [/quote] Good point. Tried reset()-ing but didn't do much. Also, printing the allocator's allocatedSize() shows constant ~2.5MiB There was no point really in doing this, it was mostly me playing with the Metal 4 API. If this is a legal program it should not leak is my position. It has to be the buffer. This version works and does not leak: func draw(in view: MTKView) { guard let drawable = view.currentDrawable else { return } commandQueue.waitForDrawable(drawable) commandQueue.signalDrawable(drawable) drawable.present() print(self.allocator.allocatedSize()) self.allocator.reset(); } but this version of draw does: func draw(in view: MTKView) { guard let drawable = view.currentDrawable else { return } commandBuffer.beginCommandBuffer(allocator: allocator) commandBuffer.endCommandBuffer() commandQueue.waitForDrawable(drawable) commandQueue.commit([commandBuffer]) commandQueue.signalDrawable(drawable) drawable.present() print(self.allocator.allocatedSize()) self.allocator.reset(); }``` Both of those aren't fully working though, as the view does not display its clear color. Something's not working right, I think. I'll file a bug.

To clarify: this happens only for apps using the Metal 4 API. I can profile pre-Metal 4 apps on the Studio just fine.

Thanks for your comment, and yeah, I figured as much by reading and playing around with various lifetimes.