If you saw our Apple Mac Mini M4 article this week, we featured the RaidenDigit 25GbE Thunderbolt adapter. Some folks have asked about this, since it is pretty awesome. The challenge, sadly, is that the status of these is in doubt to say the least. As a result, we are just going to do a quick Thanksgiving look at the solution.
RaidenDigit LightONE 25GbE Thunderbolt Adapter
The unit that we received came in a decent box.
We have used this with the new Mac Mini M4, a Macbook Pro M1 and M4, and the ASUS ROG NUC. On one face you get a vent, then SD card slots, and four Type-C connectors. Two of the Type-C ports are USB and two are Thunderbolt 3. You can daisy chain off of these apparently.
On the side, you get four USB 3 Type-A ports. That is nice since many mini PCs lack enough Type-A ports, and Apple is moving away from Type-A ports entirely.
On the other faceplate, you get the two SFP28 ports, a DisplayPort 1.4a. There is also a power input. Ours came with a non-US GAN USB PD adapter, so we just used a SlimQ adapter and it worked perfectly. (Amazon Affiliate) The unit is supposed to put out up to 85W to the Thunderbolt device, but if you have a lower-power system that supports power input via the Thunderbolt port, then this can be very useful. Figure 15-20W for the Thunderbolt dock and that can help with power budgeting.
The 25GbE ports are powered by what appears to be the NVIDIA Mellanox ConnectX-4 Lx which has been an ultra-popular data center NIC. We have seen some Thunderbolt 10G adapters using Aquantia chips, but this is a step up to a real data center part. The catch, however, is that on a 40Gbps Thunderbolt 3 link, it is really hard to drive 25GbE at full speeds. Our Kickstarter kit had an included SFP to 1GbE adatper. Another option is to use one port as SFP+ fiber and one as 10Gbase-T via an adapter and those can be driven concurrently over Thunderbolt.
The fan is needed since the NVIDIA ConnectX-4 Lx part is 10W+ so there is a 20mm fan. When it spins up, especially with a SFP+ to 10Gbase-T adapter installed in the dock, it is far from silent. This is one that would be awesome if they fixed in a future version. Passive cooling is much better for a dock like this.
RaidenDigit LightONE 25GbE Performance
25GbE felt somewhat optimistic over Thunderbolt 3, so we took this one for a spin just blasting traffic.
It looks like we were getting closer to 21-22Gbps, although there is a video online with it running at 23.5Gbps. Still, we are in a realm more than twice that of the 10G Thunderbolt adapters.
The Challenge
At this point, you might be thinking “this is great” and it is. Like with many things in life, there is also a catch. This was a Kickstarted project we backed (we were one of 44) in January 2024, and it arrived just a few weeks ago. Since it was a Kickstarter campaign, we knew there was substantial risk to the May 2024 estimated date. Like many Kickstarter campaigns we back, 4-5 months after ordering, we forgot about it, so seeing it show up was a great surprise!
Since then though, the website is not active. The Kickstarter was last updated a few weeks ago. How much do they cost now? Can we get another one or two of these at this point? Hopefully they made enough of these and can start selling them. Many STH readers will likely be interested since these are perhaps the best Thunderbolt docks out there if you need 25GbE connectivity.
Final Words
Some folks will undoubtedly say “21-22Gbps is not 25GbE speeds” which is somewhat fair. It does not hit 25GbE. On the other hand, it is still more than twice as fast as a 10GbE adapter over a single cable. Having the second port is also a big deal since it means that you can connect to a 25GbE network and a 1GbE network simultaneously which can come in handy. Imagine a NUC server that has an extra 1GbE and 25GbE port!
Is this little box perfect? Absolutely not. Make no mistake, if you have a Thunderbolt equipped laptop or mini PC and want to access fast network storage, this is the best dock we have seen. Plus, there are plenty of other ports as well. Hopefully we did not just buy a 1 of 50 unit because this is one that the STH crew might really like. Not only would our readers have a use for this in static setups, but it is small enough that it can be a portable 25GbE adapter as well.
USB type-A ports need to finally die. On a product like this, just speechless.
Nah. USB type-A ports are going to be around for a while. I would rather see them on a dock than on a NUC or Mac Mini where space is limited.
how does it work to supply 2x 25Gbit/s if Thunderbolt 3 only comes with 40 GBit/s
Somehow this does not add up
It doesn’t add up because you simply can’t saturate both ports concurrently. The point is that you can use one link at near-full-speed (PCIe speeds are somewhere around 22-24Gbps on the JHL8440 chipset, although I don’t know what this is using) and can have the other one also connected to something. But saturating both links at the same time won’t work.
My main concern is the fan. I had docks with fans before (Dell TB16 and WD19TB) and even the latter, which was fairly quiet, used to annoy me in a quiet room at home. I don’t think it would be an issue in an office environment, but I’m not getting anything with a fan for home use.