Update performance measures.

Author: pcuenca

README.md

@@ -12,9 +12,14 @@ For faster inference, we use a very fast scheduler: [DPM-Solver++](https://githu
 ## Compatibility
 
 - macOS Ventura 13.1, iOS/iPadOS 16.2, Xcode 14.2.
-- Performance (after initial generation, which is slower)
-  * ~10s in macOS on MacBook Pro M1 Max (64 GB).
-  * ~1 min 15s in iPhone 14 Pro.
+- Performance (after the initial generation, which is slower)
+  * ~8.3s in macOS on MacBook Pro M1 Max (64 GB). Model: Stable Diffusion v2-base, ORIGINAL attention implementation, CPU + GPU.
+  * 23 ~ 30s on iPhone 13 Pro. Model: Stable Diffusion v2-base, SPLIT_EINSUM attention, CPU + Neural Engine, memory reduction enabled.
+
+Performance on iPhone is somewhat erratic, sometimes it's ~20x slower and the phone heats up. This happens because the model could not be scheduled to run on the Neural Engine and everything happens in the CPU. We have not been able to determine the reasons for this problem. If you observe the same, here are some recommendations:
+- Kill apps you are not using.
+- Let the iPhone cool down before repeating the test.
+- Reboot your device.
 
 ## How to Build