I have been researching USB-A to USB-A 3.0+ Data Transfer Cables / USB Bridge Cables / USB Networking Cables / USB Crossover Cable (Not to be confused with USB NIC cables) and I haven't found a good solution that seems to work for Linux and Windows (throw Mac in there, too - why not).
A "USB Host to Host Connection" is what I'm after.
I'm sure I could probably "figure something out" by using one USB NIC at each end, and use a CAT5/6 in between, but then its more complex, and you are limited to either 1Gbps, less the performance overhead, for USB 2.0 ports (or at least the SPEED of USB 2.0) at each end, so it's a bit wasteful (and probably somewhat more expensive), but the upsides to that approach is that you might want to use this "trick" for other devices in the future, and you can make/crimp/get an extremely long CAT5/6. You you get more flexibility and range.
Fair points.
But IMO things change a bit with USB 3.0, 3.1 and 3.2 (and beyond)
I've tried to find at least a pair of USB-A to USB-A Networking / Bridge Cables that are 3.0 (preferably even 3.1 or 3.2, but I'll take 3.0!).
There doesn't seem to be a lot of actual devices for sale out there that we can actually buy and have great reviews or performance. As in, even though the cable is "marketed" as USB3.0, it is limited around 1-2Gbps MAX (Most seem actually slower, in Real World use, as reported by what few users share any benchmarks...) - That's a far cry from the theoretical 5Gbps maximum of USB3.0, though...
That seems like a market opportunity, but perhaps there is a reason?
From what I gather, the few USB3.0 cables that are out there that "market themselves" as supporting either ONLY Windows or ONLY Mac, and they use some kind of "special app" that needs installed to "make it all work".
While I'm not at all a fan of such apps / bloatwares, if it was known to work well at speeds closer to 5Gbps for data transfers between both Windows and Linux (obviously also Windows-to-Windows and Linux-to-Linux) then I'd jump for that option.

So where is that option?
I see this post from way back in the day - How do I connect two computers using USB 3.0? - In the comments, someone has supposedly written a patch for getting that particular cable to work with Linux. Cool... But feels like "its going to be janky...", before it even arrived to your mailbox.
So, why do I want this? Why would I prefer a USB-to-USB Connection?
It's kind of complicated, but not really. For my particular use case that I have in mind, I have an aging NAS box with 1Gbps ethernet, and 2x USB 3.0 ports on 2 separate USB3.0 channels. This box has no video out, and it can be modded to run a headless Linux OS. The stock firmware is pretty bad, compared to what can be done with a lightweight gui or even web management, but it does have "barely useful" features like SFTP, SMB and NFS. The 4x drives installed are SATA III (SATA 600) and after an upgrade to better HDDs, the performance of a Single HDD is actually WAY higher than what the 1Gbp NIC is able to provide. (~125MB/s is as good as it gets). So while there are RAID options like R0/1/5/10, the only gains are from redundancy(mirrors) rather than stripes. (ZFS is probably out of the question since the RAM is EXTREMELY limited and soldered on).
- There is also the issue that the NAS Box uses a pretty old ARM chip that "doesn't do well" with volumes/partitions over 16TB, so that's another caveat, but not a show stopper. The "best workaround idea" I've heard thus far is using iSCSI/multipath from remote PCs/Servers and partitioning however I want that way, via ZFS or otherwise. but for that to really make sense in terms of performance, I need to find a way to get closer-to- USB3.0 speeds, somehow.
So, assuming Linux is running on this old NAS, and the drives are configured some kind of a 2x2 Mirror or a RADI5/10 set of 4, the performance is forever limited by the 1Gbps NIC. I could add some more USB NICs and play with LACP/teaming, which is likely what I'm going to end up doing if I don't find a better solution. But wouldn't it be great to find a USB3.0 cable that could be attached directly to a PC/Server (~300+MB/s) AND a 1Gbps network connection (~125/MBs)?
I think so.
Has anyone had any luck with at least ~3Gbps data transfer speeds with a USB3.0 "bridge" cable? I did a few basic searches here on STH and didn't find much on the topic, nor did I see much (worth sharing here) on the entirety of the internet, at large.
Or maybe there is an even better solution that someone could share?
I have used CAT5 crossover cables before (back in the day when you had to crimp them yourself) and those are cool for one-off situations, but I like the idea of not having to keep a NAS *and* a PC/Server "always on" and do some extra error prone storage server configurations just to share a few drives, but I'd be willing to entertain creative solutions.
I'm also not sure if doing something wild and crazy like a 2x (or more) CAT5/6 Crossover cable LACP/Port Trunking would work (in a consistent and reliable way), but I'd love to hear about anyone who might have tried something like this before.
Here is a terse summary of what I've come (up empty) to find on this topic:
- There is a company with a name that sounds like it came straight out of the Office Space movie that seems to have moved away from offering a "magic port" with a "special cable" on a USB Hub that was cable of USB 2.0 Data Transfer speeds. I did a quick review of the current product offerings and there doesn't seem to be any kind of "magic port" options anymore on its USB3.2 products
- What few offerings I could find on "the big A" were "markety-markety-markerty-ing" USB 3.0, but actual transfer speeds were atrociously slow. The best I could confirm was about 40MB/s from the very limited options available.
- Basically: Same for "the Egg"
- I see limited stuff on fleaBay, too, but without better reviews and specifics on data transfer rates and/or "it took X amount of time transfer X amount of data" type of comments, its impossible to know if it would be a better solution that using something like a couple of 1Gbe USB NICs or a 2.5Gbe USB NIC, instead. (Isn't it weird that NO ONE seems to have included a CMD benchmark test screenshot for ANY of these products for over a decade??)
I understand that my use case is somewhat of an edge case, as usually you wouldn't want/need to keep a USB bridge cable "forever connected", you would probably use such a cable for something like a one-off situation or a "quick transfer" - but I assume the reason these cables are not more prolific in the marketplace, is because with speeds THAT slow, its faster to physically remove a drive and hook it up to the target machine with the target drive and/or use something like a SATA/NVMe to USB3.0 adapter that could get the job done 5 to 8 times faster. So what's the point? But still, it seems like I might be missing something here, or I've identified a gap in the marketplace (albeit it is likely very niche and narrow).
Anyway, I'd love to hear from the community about:
- Experience using iSCSI (with or without ZFS) over 1Gbe USB and / or 2.5Gbe USB 3.0 NICs
- Experience using iSCSI (with or without ZFS) over LACP/Port Trunking/Teaming NICs
- Experience using iSCSI (with or without ZFS) over (*NON* USB) CAT5/6 Crossover Cables
- Experience using iSCSI (with or without ZFS) over (*NON* USB) CAT5/6 Crossover Cables with LACP/Port Trunking/Teaming NICs
- Experience using USB Networking between Linux machines
- Experience using USB Networking between Linux and Windows machines
- Any other ideas for squeezing performance from a NAS device that has better performance capabilities than its NICs can provide to the network
A "USB Host to Host Connection" is what I'm after.
I'm sure I could probably "figure something out" by using one USB NIC at each end, and use a CAT5/6 in between, but then its more complex, and you are limited to either 1Gbps, less the performance overhead, for USB 2.0 ports (or at least the SPEED of USB 2.0) at each end, so it's a bit wasteful (and probably somewhat more expensive), but the upsides to that approach is that you might want to use this "trick" for other devices in the future, and you can make/crimp/get an extremely long CAT5/6. You you get more flexibility and range.
Fair points.
But IMO things change a bit with USB 3.0, 3.1 and 3.2 (and beyond)
I've tried to find at least a pair of USB-A to USB-A Networking / Bridge Cables that are 3.0 (preferably even 3.1 or 3.2, but I'll take 3.0!).
There doesn't seem to be a lot of actual devices for sale out there that we can actually buy and have great reviews or performance. As in, even though the cable is "marketed" as USB3.0, it is limited around 1-2Gbps MAX (Most seem actually slower, in Real World use, as reported by what few users share any benchmarks...) - That's a far cry from the theoretical 5Gbps maximum of USB3.0, though...
That seems like a market opportunity, but perhaps there is a reason?
From what I gather, the few USB3.0 cables that are out there that "market themselves" as supporting either ONLY Windows or ONLY Mac, and they use some kind of "special app" that needs installed to "make it all work".
While I'm not at all a fan of such apps / bloatwares, if it was known to work well at speeds closer to 5Gbps for data transfers between both Windows and Linux (obviously also Windows-to-Windows and Linux-to-Linux) then I'd jump for that option.

So where is that option?
I see this post from way back in the day - How do I connect two computers using USB 3.0? - In the comments, someone has supposedly written a patch for getting that particular cable to work with Linux. Cool... But feels like "its going to be janky...", before it even arrived to your mailbox.
So, why do I want this? Why would I prefer a USB-to-USB Connection?
It's kind of complicated, but not really. For my particular use case that I have in mind, I have an aging NAS box with 1Gbps ethernet, and 2x USB 3.0 ports on 2 separate USB3.0 channels. This box has no video out, and it can be modded to run a headless Linux OS. The stock firmware is pretty bad, compared to what can be done with a lightweight gui or even web management, but it does have "barely useful" features like SFTP, SMB and NFS. The 4x drives installed are SATA III (SATA 600) and after an upgrade to better HDDs, the performance of a Single HDD is actually WAY higher than what the 1Gbp NIC is able to provide. (~125MB/s is as good as it gets). So while there are RAID options like R0/1/5/10, the only gains are from redundancy(mirrors) rather than stripes. (ZFS is probably out of the question since the RAM is EXTREMELY limited and soldered on).
- There is also the issue that the NAS Box uses a pretty old ARM chip that "doesn't do well" with volumes/partitions over 16TB, so that's another caveat, but not a show stopper. The "best workaround idea" I've heard thus far is using iSCSI/multipath from remote PCs/Servers and partitioning however I want that way, via ZFS or otherwise. but for that to really make sense in terms of performance, I need to find a way to get closer-to- USB3.0 speeds, somehow.
So, assuming Linux is running on this old NAS, and the drives are configured some kind of a 2x2 Mirror or a RADI5/10 set of 4, the performance is forever limited by the 1Gbps NIC. I could add some more USB NICs and play with LACP/teaming, which is likely what I'm going to end up doing if I don't find a better solution. But wouldn't it be great to find a USB3.0 cable that could be attached directly to a PC/Server (~300+MB/s) AND a 1Gbps network connection (~125/MBs)?
I think so.
Has anyone had any luck with at least ~3Gbps data transfer speeds with a USB3.0 "bridge" cable? I did a few basic searches here on STH and didn't find much on the topic, nor did I see much (worth sharing here) on the entirety of the internet, at large.
Or maybe there is an even better solution that someone could share?
I have used CAT5 crossover cables before (back in the day when you had to crimp them yourself) and those are cool for one-off situations, but I like the idea of not having to keep a NAS *and* a PC/Server "always on" and do some extra error prone storage server configurations just to share a few drives, but I'd be willing to entertain creative solutions.
I'm also not sure if doing something wild and crazy like a 2x (or more) CAT5/6 Crossover cable LACP/Port Trunking would work (in a consistent and reliable way), but I'd love to hear about anyone who might have tried something like this before.
Here is a terse summary of what I've come (up empty) to find on this topic:
- There is a company with a name that sounds like it came straight out of the Office Space movie that seems to have moved away from offering a "magic port" with a "special cable" on a USB Hub that was cable of USB 2.0 Data Transfer speeds. I did a quick review of the current product offerings and there doesn't seem to be any kind of "magic port" options anymore on its USB3.2 products
- What few offerings I could find on "the big A" were "markety-markety-markerty-ing" USB 3.0, but actual transfer speeds were atrociously slow. The best I could confirm was about 40MB/s from the very limited options available.
- Basically: Same for "the Egg"
- I see limited stuff on fleaBay, too, but without better reviews and specifics on data transfer rates and/or "it took X amount of time transfer X amount of data" type of comments, its impossible to know if it would be a better solution that using something like a couple of 1Gbe USB NICs or a 2.5Gbe USB NIC, instead. (Isn't it weird that NO ONE seems to have included a CMD benchmark test screenshot for ANY of these products for over a decade??)
I understand that my use case is somewhat of an edge case, as usually you wouldn't want/need to keep a USB bridge cable "forever connected", you would probably use such a cable for something like a one-off situation or a "quick transfer" - but I assume the reason these cables are not more prolific in the marketplace, is because with speeds THAT slow, its faster to physically remove a drive and hook it up to the target machine with the target drive and/or use something like a SATA/NVMe to USB3.0 adapter that could get the job done 5 to 8 times faster. So what's the point? But still, it seems like I might be missing something here, or I've identified a gap in the marketplace (albeit it is likely very niche and narrow).
Anyway, I'd love to hear from the community about:
- Experience using iSCSI (with or without ZFS) over 1Gbe USB and / or 2.5Gbe USB 3.0 NICs
- Experience using iSCSI (with or without ZFS) over LACP/Port Trunking/Teaming NICs
- Experience using iSCSI (with or without ZFS) over (*NON* USB) CAT5/6 Crossover Cables
- Experience using iSCSI (with or without ZFS) over (*NON* USB) CAT5/6 Crossover Cables with LACP/Port Trunking/Teaming NICs
- Experience using USB Networking between Linux machines
- Experience using USB Networking between Linux and Windows machines
- Any other ideas for squeezing performance from a NAS device that has better performance capabilities than its NICs can provide to the network