March-2016>> Dell now are listing TB3 PCIe lanes per XPS/Precision model in an official document





Feb-2017 nando4>> Dell have certainly been made aware of the problem as their latest XPS 9560 specs now explicitly state "Thunderbolt 3 (2 lanes of PCI Express 3)". REF: http://www.dell.com/au/p/xps-15-9560-laptop/pd

Ports & Slots 1. SD card slot | 2. USB 3.0 with PowerShare | 3. Battery gauge button and indicator | 4. Kensington lock slot | 5. AC power | 6. HDMI |7. Thunderbolt™ 3 (2 lanes of PCI Express Gen 3) supporting: Power in/charging, PowerShare, Thunderbolt 3 (40Gbps bi-directional), USB 3.1 Gen 2 (10Gbps), Native DisplayPort 1.2 video output, VGA, HDMI, Ethernet and USB-A via Dell Adapter (sold separately) | 8. Headset jack

3-Jan-2017 nando4>> The conclusion of this problem is the Dell XPS 9350/9360/9550/9650 and Precision M5510/M5520 have 2 PCIe 3.0 lanes (16Gbps), wired rather than 4 PCIe 3.0 lanes (32Gbps). This is summarized at https://egpu.io/forums/pc-setup/xps-15-9550-not-able-to-reach-40gbps-over-tb3/paged/3/#post-979 and the post straight after it.

Hi,

I noticed that all devices I connect via the AKiTiO Thunder3 PCIe under perform by about 50% so I got curious and contacted AKiTiO about this issue.

They only had an XPS 13 9350 and said that in the XPS 13 the TB3 controller definitely only connected with x2.3 ( 16Gbps ) and that the HWInfo64 screenshot I send from my XPS 15 looks exactly the same as theirs on the XPS 13.

According to HWInfo64 the XPS 15 is indeed equipped with an DSL6340, so is the controller hindered by it's x2.3 or x4.2 pcie connection? Is it a hardware or software ( BIOS/Firmware ) issue?