You know, it's not really that we all don't know that Rocket lake will be PCIe Gen 4.0 compatible, it's just never been confirmed. Well, it now certainly is as a database entry from Sandra is listing Rocket lake, running with a PCIe Gen 4.0 NVMe SSD.
Current generation processors are Comet Lake, the following generation will be Rocket Lake (yes still at 14nm), it will support PCI-Express Gen4. With Rocket lake intel would be going back to 8-cores (that is a rumour though). The generation succeeding Rocket lake then would go upwards to 16 cores (8 large and 8 small cores, you know BIG-little.) Back to Rocket lake though, it is still based on a 14nm node and the LGA 1200 socket to be paired with the latest Z490 chipset based motherboards.
In case you've been wondering, Comet Lake-S processors (the current tenth generation of Intel Core for desktop) actually do support PCI Express 4.0, some Z490 motherboards are designed for it as well. However an issue prevents PCIe 4.0 to become usable, so the platform will support PCI-E 3.0 instead. The reason behind this is the presence of Jitter in the Z490 chipset signal, that causes instability in the data signal and that means that specifications required for the PCI-Express 4.0 certification are simply not met. PCI-E 4.0 is working at very high frequencies, and that requires that the signal be completely clean.
proof that Rocket Lake indeed is supporting PCIe gen 4.0 as spotted by @TUM_APISAK
Comet Lake is still an x4 DMI interlink (the link between the processor and chipset), Rocket Lake would likely get an x8 connection. In addition, the processor has received four additional PCIe lanes for a total of 20 from the CPU itself. The slide also mentions Thunderbolt 4, which would provide the same speeds as Thunderbolt 3, we're not quite sure what there would be new on that front though.
| Kaby Lake-S | Coffee Lake-S | Comet Lake-S | Rocket Lake-S | Alder Lake-S | |
|---|---|---|---|---|---|
| Fabrication Node | 14nm | 14nm | 14nm | 14nm (TBC) | (TBC) |
| Launch Date | 2017 | 2018 | 2020 | (TBC) | (TBC) |
| Chipset | Intel 200 | Intel 300 | Intel 400 | Intel 500 | Intel 600 |
| Core Series | 7th Gen Core-S | 8th/9th Gen Core-S | 10th Gen Core-S | 11th Gen Core-S | 12th Gen Core-S |
| Max Core Count | up to 4 cores | up to 8 cores | up to 10 cores | TBC | up to 16 (TBC) |
| Socket | LGA1151 | LGA1151 | LGA1200 | LGA1200 (TBC) | LGA1700 (TBC) |
| Memory Support | 2ch DDR4 up to 64GB | 2ch DDR4 up to 128GB | 2ch DDR4 up to 128GB | 2ch DDR4 up to (TBC) | (TBC) |
| PCIe Support | PCIe 3.0 | PCIe 3.0 | PCIe 3.0 | PCIe 4.0 | PCIe 4.0 |
| CPU PCIe Lanes | 16 (3.0) | 16 (3.0) | 16 (3.0) | 20 (4.0) | (TBC) |
| PCH PCIe Lanes | 24 (3.0) | 24 (3.0) | 24 (3.0) | 24 (3.0) | (TBC) |
| USB | up to 10x 3.0 up to 14x 2.0 |
Z370: up to 10x 3.0 up to 14x 2.0 Z390: up to 6x 3.1 Gen2x1 up to 10x 3.1 Gen1x1 |
3.2 Gen 2×1 (10 Gb/s) 3.2 Gen 1×1 (5 Gb/s) 2.0 |
3.2 Gen 2×2 (20 Gb/s) 3.2 Gen 2×1 (10 Gb/s) 3.2 Gen 1×1 (5 Gb/s) |
(TBC) |
| DMI | x4 3.0 | x4 3.0 | x4 3.0 | x8 3.0 | (TBC) |
| Integrated WiFi | – | Wireless-AC | Wireless-AX | Wireless-AX | (TBC) |
| Display Support | DisplayPort 1.2 HDMI 1.4 |
DisplayPort 1.2 HDMI 1.4 |
DisplayPort 1.2(1.4) HDMI 2.0a |
DisplayPort 1.4a HDMI 2.0b |
(TBC) |
| Intel SGX Security | 1.0 | 1.0 | 1.0 | - | (TBC) |
Intel Rocket Lake-S confirmed with PCI-Express 4.0 support
