4 thunderbolt ports on the model? 40GBps on each port?

[joevt]

Framework uses Tiger Lake CPU which has integrated USB4/Thunderbolt 4 controller so it wouldn’t need a JHL8540 Maple Ridge discrete Thunderbolt controller.

Thunderbolt 4

I recently received my Framework laptop, and running lspci and lshw, and the chipset definitely register as Thunderbolt 4: [lspci_framework] My guess is they did everything to have it in, but they just have to complete the process with Intel to advertise it as a thunderbolt 4. But everything points toward every ports being fully capable thunderbolt 4 ports.

Maybe it uses JHL8040R Retimer?

Anyway, with TigerLake Thunderbolt 4:

• There’s one USB controller for the USB 3.1 gen 2 functionality of all four ports. Probably this also gets used for USB tunnelling functionality of the USB4 controller when a USB4 dock/hub is connected.
• There’s two (I guess one for each side?) NHI controllers (USB4 controllers) for USB4 stuff (Thunderbolt IP networking between two hosts, etc.).
• There’s four PCIe root ports for Thunderbolt PCIe tunnelling (for PCIe devices in Thunderbolt 3 docks/displays).

I suspect the total bandwidth will be similar to Ice Lake: ≈40 Gbps of PCIe data for all 4 ports combined. Each port can probably do around ≈23 Gbps of tunnelled PCIe data (and tunnelled USB 3.1 gen 2). The rest of the 40 Gbps for each port is useable by DisplayPort tunnelling.
https://egpu.io/forums/laptop-computing/ice-lake-cpu-on-die-thunderbolt-3-controller-bandwidth/

DisplayPort tunnelling can do up to 34.56 Gbps (two HBR2 x4 connections of 17.28 Gbps).

The 32.4 Gbps number is HBR3 x4 on the DisplayPort wire (after the downstream Thunderbolt controller converts the tunnelled DisplayPort from the host back to regular DisplayPort. It is 25.92 Gbps of DisplayPort data. With one HBR3 connection, you can also include an HBR connection (8.64 Gbps).

Apple is able to use some trick to get two HBR3 x4 connections over Thunderbolt 3 for the Apple Pro Display XDR to get 6K 60Hz 10bpc RGB with a GPU that doesn’t support DSC. They don’t use this trick if there’s a Thunderbolt device (or a optical cable) between the host and the XDR. Two HBR3 connections is 51.84 Gbps which is more than Thunderbolt 3/4 can handle, but it works because Thunderbolt does not send the stuffing symbols that DisplayPort uses to fill the HBR3 bandwidth. This trick uses 38.9 Gbps of tunnelled DisplayPort which makes the XDR’s 5 Gbps USB hub not able to transmit 5Gbps (I’m not sure if you can receive 5 Gbps of USB from the XDR - it may be possible if the hub is not altered to only support USB 2.0 in this case).

Tiger Lake supports DSC, so the Apple Pro Display XDR should be able to connect with just one HBR2 x4 connection (6K 60Hz 12bpc RGB with DSC 3:1 compression). And in fact you should be able to connect two of them to a single Thunderbolt port (but I’m not sure if the Intel graphics of the Tiger Lake can handle that many pixels per second). With DSC, the XDR can send and receive 5 Gbps of USB.

8K60K using HBR3 x4 requires DSC or chroma sub sampling.