Hi Evereyone, I just bought a Asus ROG GL702VM a little better than the GL502VM . Well it can be a hit or a miss when it comes to what speed you will get with your thunderbolt 3 port either 20gbits/ or 40gbits . Asus is very vague and sketchy. Heres a Forum Post that will help a bit.
https://rog.asus.com/for...lt-3-port-in-the-GL502VM

I cancelled my order.

I am using the GL502VM with Sonnet Echo T3 into the Thunderbolt 3 connection and I have a Decklink Duo 2 inside it. So 4 cameras going strong. I have also successfully came out of the T3 extra port on the Sonnet device into a Startech T3 to T1/T2 device and used it with Mini Recorder and all is perfect. I bet it is your cable. The Belkin T3 Cable is rated 20GB Per Second not 40GB. Be careful what cable you order.

I have done some testing with this and a Decklink Quad 2 card.

I used an ASUS G750JW with thunderbolt 1 10Gbps, an ASUS GL502VM with thunderbolt 3 20Gbps, an Akitio Thunder2 and an Thunder3.


The results are very linear.

On my Thunderbolt 1 10Gbps config I can get maximum 3x 1080p60 inputs before starting to drop frames at source.
On my Thunderbolt 3 20Gbps config I can get maximum 6x 1080p60 inputs before starting to drop frames at source.


We also did some massive tries at getting a MSI TITAN GT73VR to work with this, which does have full 40Gbps TB3, but never got any decklink card to work with it. (Possibly TB3 NVM firmware needed, but MSI hasn't released any.)

If you use 1080p30, 1080i or 720p and/or live in the PAL region (50/25) you should get many more inputs working due to bandwidth. 8x 720p60 worked perfectly on my Thunderbolt 1 config.

Back with more testing;

Asus G752VS with Akitio Thunder3 which allegedly has 40gbps TB3 (see images for chip details):

Suprisingly enough; same results as ASUS GL502VM with thunderbolt 3 20Gbps: Max 6x 1080p60

Might this be because many (including the Thunder 3) of the thunderbolt enclosures are 4x while the card is 8x?

I don't have any knowledge about how the PCIe gen 3.0 4x works with the PCIe gen 2.0 8x of the Quad 2 card.

Maybe the physical pinout for the PCIe bandwidth is missing while the actual thunderbolt bandwidth is there?

I put together a small album of relevant images:

http://imgur.com/a/FDOwA


Is there any PCIe 8x boxes out there with a thunderbolt 3 interface? (EDIT: Found one: http://www.sonnettech.co.../echoexpressse1tb3.html)


EDIT:

Is PCIe 3.0 4x a limitation of the Thunderbolt 3 connection itself? Can it be converted/adapted to 2.0 8x?



^from the official thunderbolttechnology.net website

DOUBLEEDIT:

Does this mean it doesn't matter if you get the 20gbps or 40gbps chip, or even a thunderbolt 2 enclosure as long as a) your card does not support PCIe 3.0 or b) you are not going to daisychain more devices?

Would two Decklink Duo 2 cards in 2 thunder3 chassises daisychained work as expected?

Seems as though some Dell XPS 15 9550 users are complaining about the same issue.

https://www.reddit.com/r/Dell/co...o_reach_40gbps_over_tb3/

I wonder if users of other brands of TB3 laptops are raising this issue?

I know this is an old thread, but still: this page is quite informative, about how to get the most out of a Thunderbolt3 connection on selected laptops.
"eGPU.io user builds listed as 32Gbps-TB3 are confirmed to offer full Thunderbolt 3 bandwidth performance."