I am always wondering if there is any laptop with 4 RAM slots, so I can install 128GB ram myself for my special use case. Any ideas?
Laptop with 4 RAM slots

Comments
 - Maybe they want to open more than 10 tabs in Chrome?  - I have about 25 on average open with 8 GB RAM, and on multiple windows. Not really a problem if just using browser on itself. - 16GB or 32 GB is more than enough for a laptop form factor. above that is just wasting money on laptop, and would be better of with desktop 
 - More likely they want to run VMs. 
 
 - But think how super duper speedy that PC will run! (/s) 
 
 - There are workstation class laptops. HP Zbooks for example, have 4 memory slots and support higher memory capacities. - eg Zbook Fury https://h20195.www2.hp.com/v2/GetDocument.aspx?docname=c0814… - Very popular with architects that need mobility and also need to run tools that need gobs of RAM. 
 - Google: Laptop 128GB RAM — that gives you workstation class laptops from Dell, Lenovo and HP. Not all them have 4x SO-DIMM slots, as there seems to be 64GB DDR5 SIMM available. - Alternatively, run remote desktop to a workstation desktop. 
 - It’s very uncommon in consumer laptops. 
 However, the MSI Titan GT77 has 4 DDR5 Sodimm Slots and the older GT76 had 4 DDR4 slots
 The GT77 costs $6099
 - You are looking for workstation laptops. Normal consumer laptops rarely have more than 2, I cant even think of one off the top of my head. - Be ready to pay workstation/business pricing. - DDR5 also has a spec for 64gb sticks, but I am yet to see a 64gb sodimm module. I imagine they will arrive as ddr5 production ramps up. May be worth waiting. 
 - ThinkPad P16 Gen 1 
 - Look at professional laptops. Dell Precision, HP Zbooks etc. 
 Would help stating the special use case.

You would be looking at a desktop man,
Dont really think a laptop to have 4 slots. and why you need 128GB ram on a laptop ? its too much RAM, Put it on a desktop.