The way it works, per a Wednesday post on X: 

"Grok is the master conductor/navigator with deep understanding of the world to direct digital Optimus, which is processing and actioning the past 5 secs of real-time computer screen video and keyboard/mouse actions. Grok is like a much more advanced and sophisticated version of turn-by-turn navigation software."

So Digital Optimus is the 'instinct' while Grok is the 'thinking part of the mind' according to Musk. 

The setup will run "very competitively on the super low cost Tesla AI4 ($650) paired with relatively frugal use of the much more expensive xAI Nvidia hardware," and "will be the only real-time smart AI system." 

"In principle, it is capable of emulating the function of entire companies. That is why the program is called MACROHARD, a funny reference to Microsoft." -Elon Musk

It gets even more wild; Musk says it works "in all AI4-equipped cars, so your car can do office work for you when not driving," and he will deploy millions of dedicated Digital Optimus units at Supercharger stations.

Grok itself suggested 10 use cases;

1. Auto data entry from invoices/docs. 
2. Real-time code fix from error messages. 
3. Deal hunting while shopping online. 
4. Contextual email response generation. 
5. Seamless enterprise software ops. 
6. Auto video edits from timeline. 
7. Live stock trade execution. 
8. Tutorial step automation. 
9. Instant security threat spotting. 
10. Entire company workflow emulation. 

According to Musk, Digital Optimus will be ready to rock in 6 months. 

xAI was acquired by SpaceX last month in an all-stock deal that valued the rocket maker at $1 trillion and xAI at $250 billion, which comes ahead of a potential SpaceX IPO later this year.