why do Xeon Platinum only have 3 UPI links?

[LukeP]

Intel® Xeon® Platinum 8180 Processor (38.5M Cache, 2.50 GHz) Product Specifications

i thought Gold is 2P and Platinum is 4P+ processors. why only 3 UPI links?

and what does this mean?

• ScalabilityS8S

thanks!

 

[Patrick]

Will go pull the 8S slide in a sec.

Gold 5100, Silver, Bronze 2x UPI

Gold 6100 and Platinum 3x UPI

All Gold and Platinum 4S capable. Platinum 8S(+)

Good read will update this thread soon Intel Xeon Scalable Processor Family: Platinum Gold Silver Bronze Naming Conventions

 

[BlueFox]

You don't need 7 UPI links per CPU in an 8 socket configuration. 3 will do to have full connectivity (imagine a cube with each processor being a corner the 3 lines drawn between them)

As for "ScalabilityS8S", just means it will do 8 sockets.

 

[Patrick]

Nevermind, we did publish the slide. Here are the Topologies and how you get to 8S: Intel Xeon Scalable Processor Family Platform Level Overview

The Key takeaway is that each die can only be connected to two neighbors (2 UPI) or 3 neighbors (3UPI)