Question Thunderbolt P2P / TB4 - 1.5GB/s

[Tech Junky]

So, I've been playing with my setup and someone asked about TB P2P networking and since I have TB on 2 devices decided to take a stab at it before caving to 10GE Ethernet which would run me ~$300 for a NIC / TB3 adapter for the laptop. Figured a $50 cable between the two devices might yield better speeds for cheaper. The $50 cable is 10ft which means not having to get so close to the source of the data while copying things.

So, I tested the new cable and an existing 3ft option I had already and both link up at 20gbps and yield 1.5GB/s in transfers which is on par for the laptop doing an internal to internal between NVME drives.

This is going to/from Linux / Windows.

 

[Tech Junky]

OK.. so, I obviously have some odd issue here with Linux being stubborn. Turns out all 3 cables work just fine. They all hit over 1GB/s for transfers and link at 20gbps.

I stumbled upon something that seems to indicate this will be the case regardless as each side sees 20gbps tx//rx as the links speed when using P2P networking.

My work around is to manually bring up the interface on the linux side by running 2 commands in my case.

sudo ifconfig thunderbolt0 up && sudo ip link set thunderbolt0 master br0

I have the TB interface in my /etc/network/interfaces fiile as a hot plug / br0 member but, the mechanism in linux is being dumb and not adding / up the IF when plugged in. This is probably some weird config change I need to make as it seemed to work just fine the other day when testing the first cable. I've attacked it on a couple of fronts though and just need to work through the process or manually activate it with my new button I made with the commands when I want to use it.

So, the cables I tested are....
https://www.amazon.com/dp/B09SD7DR2L - $30 w/ coupon ~10ft passive
https://www.amazon.com/dp/B08XLRQXTH - $40 -- ACTIVE 6.6FT
https://www.amazon.com/dp/B0C58GF6BZ - $50 w/ coupon ~10ft passive

I thought the ACTIVE version might work some magic and get the link rate up but, alas it didn't do anything different. Just like the initial round of testing with the enclosure even the cheap $10 cable worked just as well just a shorter distance at 3.3ft - https://www.amazon.com/gp/product/B093FQSYLB Which looking at the listing again they sell a 6.6FT for $15... Might be ordering that and cutting the cost in 1/2 from the Yotta. Though 6.6 means being closer to the server vs sitting comfortably a tad further away.

Since this TB P2P thing only does 20gbps regardless of the length / active/passive I went and tested my cheap USB 10ft cable and didn't work but, just making sure since the other cheap 3.3 Necktek one does 20gbps. Too many options to play with.

Anyway... so, you can get at least 10GE performance from a P2P TB connection for less cash. Might not hit amazing speeds but, for $30 cable and two PCs w/ TB ports already it's considerably cheaper.