We all know standard parallel DDR memory is reaching physical limits on motherboards, and HBM is far too expensive. The server-market uses CXL Memory Expanders, but no one has adapted this concept for the Desktop market yet.
I just published a draft for the XMM (eXpress Memory Module) Architecture. The core idea is moving the memory controller (OBMC) OFF the CPU die and onto a PCIe/CXL add-in card.
Why it matters:
Motherboards get massively cheaper (no more 150+ parallel impedance-matched traces).
CPU sockets free up ~300+ pins, which can be reallocated for VCORE or more PCIe lanes.
True Modular Unified Memory for Desktop PCs.
We have a photorealistic concept render in the repo of what the card looks like.
Hey everyone,
We all know standard parallel DDR memory is reaching physical limits on motherboards, and HBM is far too expensive. The server-market uses CXL Memory Expanders, but no one has adapted this concept for the Desktop market yet.
I just published a draft for the XMM (eXpress Memory Module) Architecture. The core idea is moving the memory controller (OBMC) OFF the CPU die and onto a PCIe/CXL add-in card.
Why it matters:
Motherboards get massively cheaper (no more 150+ parallel impedance-matched traces).
CPU sockets free up ~300+ pins, which can be reallocated for VCORE or more PCIe lanes.
True Modular Unified Memory for Desktop PCs.
We have a photorealistic concept render in the repo of what the card looks like.
Check out the specification and the RFC repository here: https://github.com/Luiguard/XMM-Standard
I'd love to hear some harsh engineering feedback on protocol limits, lane starvation, and bootstrapping!