Intel 8th Gen Core with Radeon RX Vega GPU Presentation

Re:Intel 8th Gen Core with Radeon RX Vega GPU Presentation by bryanlarsen on Sunday January 07, 2018 @04:24PM (#16092823)

AFAICT, Coffee Lake has 24 PCI-E lanes, 8 of which are used to connect to the chipset. If they used all remaining 16 for the GPU, then NVMe and thunderbolt connections would have to go through the south bridge, affecting latency and throughput.

[ Parent | on HN ]

Re:Intel 8th Gen Core with Radeon RX Vega GPU Presentation by dogma1138 on Sunday January 07, 2018 @06:08PM (#16093296)

Intel doesn't connect to the chipset with PCIe, it does that with DMI.

Coffee Lake only has 16 PCIE lanes on the CPU, 4 DMI Lanes (about equivalent to 4 PCIE 3.0 lanes) which connect to the PCH and 24 PCIE 3.0 lanes coming from the chipset.

[ Parent | on HN ]

Re:Intel 8th Gen Core with Radeon RX Vega GPU Presentation by bryanlarsen on Sunday January 07, 2018 @07:30PM (#16093728)

I over simplified. DMI is a PCI Express variant. I thought it had increased to 8 lanes in Coffee Lake, but I was mistaken. That makes it even more important to save some of the CPU PCIe lanes for NVMe and thunderbolt.

[ Parent | on HN ]

Re:Intel 8th Gen Core with Radeon RX Vega GPU Presentation by monocasa on Sunday January 07, 2018 @04:30PM (#16092862)

I guess I would have preferred to see it be a client on QPI and be cache coherent with the rest of the system, rather than using PCI at all, but yeah, that's asking a bit much on this super short timeframe.

[ Parent | on HN ]