The SiP is the entire package, which is essentially a miniaturized motherboard. The chip at the heart of that SiP which contains the CPU, GPU and NPU is exactly the same chip in the S9, S10 and (based on this leak) S11. Other components on the SiP have changed such as the cellular modem, WiFi and Bluetooth chips, along with repackaging to make the overall SiP more compact, but there’s no change in processing performance. The thinner profile was about making a thinner Series 10 watch without compromising battery life.