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.

 

[L&LD]

That looks very impressive.

Speeds between NVMe drives are/should be much faster though. What drives are these? What gen m.2 port are they connected to?

 

[Tech Junky]

I think part of the issue is the cable length and being a passive cable. I found a couple of active cables to test out that theory. The shorter one though I figured would max out the speed but, further digging says it's too long even though with an enclosure it hits north of 3GB/s.

Both sides are Gen 4.

Even internal copies don't hit the rated speeds though. So, it might be a limitation on the laptop side. The CDM testing though shows full speeds of the drives.

1.5GB/s though is better than relying on other network options currently. 10GE maxes out just over 900MB/s in speed. I think switching to an active cable should provide faster speeds and link at 40gbps vs 20 I'm seeing at the moment with current cables.

If I had two desktops that would be a different story being able to use NICs instead of the laptop being capped at whatever dongle option maxing at 10ge. With a NIC the speeds could be 100ge if unlimited budget were a thing.

 

[Tech Junky]

 

[sfx2000]

Here's the one I recommend... not cheap, but it's an active cable, and works great

Amazon.com

 

[Tech Junky]

Always open to ideas though Belkin for me doesn't really make a compelling argument from other items in the past.

I did order the yotta and should be able to test it tomorrow to see if the passive/active makes a difference in the link speed from 20>>40. If it does the transfers should hit at least 3GB/s or more based on the same drive used in the enclosure scenario. If it doesn't then I'll try copying to the other drive in the laptop.

 

[sfx2000]

I did order the yotta and should be able to test it tomorrow to see if the passive/active makes a difference in the link speed from 20>>40. If it does the transfers should hit at least 3GB/s or more based on the same drive used in the enclosure scenario. If it doesn't then I'll try copying to the other drive in the laptop.

Sure, let us know - if this helps, I've seen the virtual ethernet device on TB3 show up as a 20Gbit device, not 40 on Win10 with my Dell XPS13 laptop...

 

[sfx2000]

As I've mentioned many times - cable quality matters - the Belkin is a certified TB3 cable that should also work fine with USB4...

Interesting to note - CableMatters has both TB3/4 (Intel certified) and USB4 (USB-IF certified) cables - two different things... and the TB3 cable is 2x the cost of the USB4 cable...

[Intel Certified] Thunderbolt 4 USB-C Cable Supporting 100W Charging

Thunderbolt 4 Cable steps into the future of Thunderbolt with the most advanced and capable cable ever created

www.cablematters.com

[USB-IF Certified] USB-C Cable with 4K Video and 100W Power Delivery

Cable Matters USB Type-C (10 Gbps) Gen 2 Cable delivers up to a 10 Gbps data transfer speed that is 2x the speed of a Gen 1 USB-C cable.

www.cablematters.com

Anyways - it's interesting to note that the Thunderbolt community is pretty clear on their path, and the USB community is muddying the waters by saying "we're the same", but they really are not...

At a high level...

• Thunderbolt will connect to Thunderbolt or USB
• USB will connect to USB, but not to Thunderbolt

Much like all MAGA folks are Republicans, but not all Republicans are MAGA folks - hence the RINO's...

 

[Tech Junky]

@sfx2000

Yeah, I know the difference between cables. I know the difference between standards as well. USB4 is just TB3 with looser requirements such as 20mbps and single display.

The thing I'm trying to suss out is the 40 link rate whether it's possible or max due to the display reservation of TB.

Once asmedia gets their USB 4 certified though and produces a card to market I'll be switching due to higher bandwidth and only needing an x1 slot since it's gen4 unlike the TB card needing x4. The ASM card is supposed to hit 3.8 vs 3.1.

As for cables it all comes down to the chips in the connector performing the handshake to authorize. Funny thing though is I have a cheap necktek USB cable that does 20 off the TB port. My other cheap TB cable does 20 as well. I've already tested a bunch of cables when I did my enclosure speed testing.

Maybe the active cable will make a difference and maybe it won't but, if I don't try I won't know. In theory though through documentation it should link faster and provide higher speeds. I'll test with both destination drives in the laptop to rules out a bus bottleneck if the first doesn't produce higher speeds.

 

[sfx2000]

Yeah, I know the difference between cables. I know the difference between standards as well. USB4 is just TB3 with looser requirements such as 20mbps and single display.

It actually isn't - similar throughput - but the protocols are different... TB is basically PCIe over the wire, USB4 has to deal with all the USB stack mess...

that being said - USB4 has a lot of potential...

 

[Tech Junky]

Well, the whole thing is Intel removing the royalty for TB for use on USB. USB though doesn't have all of the requirements TB verification imposes. This why USB minimum is 20 and not 40 and display is 1 and not 2. USB also offers higher PD of 240 while TB is capped at 100.

 

[sfx2000]

Well, the whole thing is Intel removing the royalty for TB for use on USB. USB though doesn't have all of the requirements TB verification imposes. This why USB minimum is 20 and not 40 and display is 1 and not 2. USB also offers higher PD of 240 while TB is capped at 100.

Intel removing the royalty for TB does not mean magically USB4 is TB4 - I hope you realize this...

 

[Tech Junky]

I didn't say that it was the same. I said the differences between TB and USB4.

They both provide UP TO 40gbps but, there are differences.

 

[Tech Junky]

Well, that cable while nice in theory and price didn't do squat with TB. I guess it's time try options 2&3 and maybe 4. Syslog though kind of thinks the cable wants to connect at 20 but then times out and drops the negotiation.

 

[Tech Junky]

Dug through the certified list and there's very few 6ft cables out here that are active and should hit 40 link rate / 3GB/s actual.

Check out my list on Amazon

www.amazon.com

Based on some reviews though knocked a couple off the list but, 7 more options to test.... Truthfully I don't think I feel like dealing with that many attempts though. I did that with the enclosure testing of cables and it's tiresome documenting it and figuring out the best option. At this point it's more of a does Active link at 40 or just 20 like the other cable.

 

[sfx2000]

Well, that cable while nice in theory and price didn't do squat with TB. I guess it's time try options 2&3 and maybe 4. Syslog though kind of thinks the cable wants to connect at 20 but then times out and drops the negotiation.

That is the Yottamaster cable you screen-shot?

 

[sfx2000]

Dug through the certified list and there's very few 6ft cables out here that are active and should hit 40 link rate / 3GB/s actual.

I can speak for the Belkin and CalDigit cables as I have them and use them on a daily basis...

I also have a 1 meter cable from Apple that was included with my Studio Display, so it's a nice reference for others - and as I mentioned, CalDigit and Belkin 2 meter cables there's no difference from each other or the Apple cable.

 

[Tech Junky]

Right.

Amazon.com

Next up tomorrow.

 

[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/?tag=snbforums-20 - $30 w/ coupon ~10ft passive
https://www.amazon.com/dp/B08XLRQXTH/?tag=snbforums-20 - $40 -- ACTIVE 6.6FT
https://www.amazon.com/dp/B0C58GF6BZ/?tag=snbforums-20 - $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/?tag=snbforums-20 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. Though if you need the cards they're $80/ea but the laptop side will run about $150 for a TB 10GE dongle.

 

[sfx2000]

So, the cables I tested are....
https://www.amazon.com/dp/B09SD7DR2L/?tag=snbforums-20 - $30 w/ coupon ~10ft passive
https://www.amazon.com/dp/B08XLRQXTH/?tag=snbforums-20 - $40 -- ACTIVE 6.6FT
https://www.amazon.com/dp/B0C58GF6BZ/?tag=snbforums-20 - $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

So you did every cable but the ones I recommended... at the end of the day, a 6.6ft/2m TB3 active cable is going to cost a certain amount - and right now, that it around 60 bucks, give or take...

Amazon and other online marketplaces are full of crap...

Here's an external NVME drive - TLDR, it was a CCB with two SD-Cards and a USB2 controller on a USB-C connector...

Fake External M.2 NVMe SSD Has MicroSD Cards Inside

The cheap 512 GB drive also had an 'ancient' controller and a slow interface.

www.tomshardware.com

TB3/4 connectivity between endpoints is impressive - no doubt - Macs can do this no problem with a good cable.

When you're sharing across platforms - there's the network overhead and application overhead... this is local read/write on a MacbookPro 2019 (Core-i7)

So in some ways, the source/destination for file copies is going to be the local disk...

At the end of the day - $60 cables and $200 10gb ethernet adapters - this is the cost of doing Thunderbolt

It's always been that way - even going back to Firewire 400/800 and USB there...

There isn't really a cheap way out with TB3/4- and most folks that use Thunderbolt, it's their business, not a hobby...