Inside the IBM POWER8 chip there’s another processor! That’s right folks, you get another CPU for no extra cost (It’s a lot funnier if you say these previous two sentences as if you were presenting an informercial for a special TV offer).
It is, however, not what you’d consider a general purpose processor. It is, in fact, a PowerPC 405 – so your POWER8 processor also has another PowerPC chip in it. What’s the purpose of this chip? It’s named the On Chip Controller and it has the job of helping make the main processor (the POWER8) work.
It has two jobs:
- Monitor temperature and keep the system thermally safe
- Monitor power usage and keep the system power safe
It runs a hard Real Time OS which has just been released up on github.com/open-power/occ
It’s fairly exciting to see more of the software that runs on every POWER8 system make it out into the world.