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As an extra data-point outside the x86 world, this is also how modern POWER processors work. POWER9 integrates the PCIe and memory controllers onto the CPU die
by spijdar 6y ago
As an extra data-point outside the x86 world, this is also how modern POWER processors work. POWER9 integrates the PCIe and memory controllers onto the CPU die itself. This is one reason why then open source P9 computers from Raptor exist and have sort-of sane pricing (for such a tiny and niche market) -- a lot of the traditionally hard components are integrated onto the CPU, which makes designing boards around it that much easier vs needing complex chipsets.
- wtallis 6y agoThere are also some POWER processors that move most of the memory controller off-chip, and use a media-agnostic high speed serial link between the CPU and each memory controller chip. That allows for a lot of flexibility in tuning for memory capacity or bandwidth, at the expense of a bit of extra latency. Those CPUs end up having all of their IO in the form of high speed serial links, some used for PCIe, some for NVLink, some for CAPI/OMI.