Re:PCIe vs. CXL for Memory and Storage
by c0balt on Sunday November 05, 2023 @01:46PM
(#38154207)
> There are no AM5 motherboards with 4 2 spaced PCIe 16x slots. Why are the consumer chips even limited for IO?
Because PCIe Slots, especially Gen 5, is a good chunk of the complexity/ cost of a consumer Motherboard. They are difficult to handle as they have quite hard limits ln timing and signal integrity requirements. Hitting these requirements for more full-width slots is harder and for most use cases just not feasible from a cost : usability perspective (how many extension cards can even saturate an 8x Gen 5 Bus?). This is also why PCIe Risers for newer PCIe generations are getting very expensive.
Because PCIe Slots, especially Gen 5, is a good chunk of the complexity/ cost of a consumer Motherboard. They are difficult to handle as they have quite hard limits ln timing and signal integrity requirements. Hitting these requirements for more full-width slots is harder and for most use cases just not feasible from a cost : usability perspective (how many extension cards can even saturate an 8x Gen 5 Bus?). This is also why PCIe Risers for newer PCIe generations are getting very expensive.