Realtek showcased RTL8126, RTL8157, and RTL8251B 5 Gbps Ethernet solutions at Computex 2023, and the first Realtek RTL8126 5 Gbps Ethernet PCIe and M.2 adapters were introduced in 2024, shortly followed by RTL8157 5GbE USB 3.2 adapters.
The company has now unveiled upgraded solutions for 10 Gbps Ethernet networking at Computex 2025 with the RTL8127 10GbE PCIe controller and variants, the RTL8159 10GbE USB 3.2 Gen 2×2 controller, and the RTL8261C PHY for 10GbE switches.
Realtek RTL8127 10GbE PCIe NIC
Realtek RTL8127 specifications:
- Ethernet – 10Mps, 100Mps, 1000Mps, 2500Mps, 5000Mps, and 10Gbps
- Host interface – PCIe Gen4
- Features
- Modern standby
- Self loopback diagnostic
- Hardware ECC and CRC
- Power consumption – 1.95 Watts
- Package – 9×9 mm QFN88
The Realtek RTL8127 will be found in PCIe and M.2 cards, or directly soldered on motherboards or CPEs. The good news is the low power consumption, which should make cooling easier and cheaper (Realtek claims a $0.125 saving on heatsink) compared to competing 10GbE controllers.
Three other variants will also be offered. The RTL8127AP targets servers with DASH 1.2 remote management technology support, the RTL8127ATF for FTTx (Fiber) only, without support for 10/100 Mbps speeds, and a low power consumption of about one Watt, and the RTL8127AT is similar to the former but without fiber support.
The RTL8127ATG and RTL8127AT support either PCIe Gen 3 x2 or PCIe Gen 4 x1 for better compatibility with older motherboards.
Realtek RTL8159 10 Gbps Ethernet USB 3.2 controller
Realtek RTL8159 specifications:
- Ethernet – 10Mps, 100Mps, 1000Mps, 2500Mps, 5000Mps, and 10Gbps
- Host interface – USB 3.2 Gen2 x2
- Features
- CDC-NCM compatible
- UEFI PEX
- Hardware support for RSS
- MAC Address pass-through
- Power consumption – TBD
- Package – 8×8 mm QFN68
The RTL8159 will be integrated into USB Ethernet adapters, hub monitors, and USB docks.
RTL8261C PHY
Realtek RTL8261C 10GbE single PHY specifications:
- Ethernet Speeds – 10GBase-T, 5000Base-T, 2500Base-T, 1000Base-T, 100Base-Tx, 10Base-Te
- Interfaces – USXGMII/SFI (XFI), 5000Base-X, 5000Base-R, 2500Base-X, 1000Base-X, HiSGMII/SGMII
- Co0lab 5GbE PHY RTL8251B and 2.5GbE PHY RTL8221BN
- Power Consumption – 1.65 Watts
- Package – 8×8 mm QFN56
- Industrial grade option – RTL8261CI
The RTL8261C will be used in 5G CPE, PON, WiFi 6/7 routers, switches, and cable modems.
Pricing
While Realtek did not directly disclose pricing information, TechPowerUp reported that a representative insinuated that the new 10 Gbps chips would be less than double the price of Realtek’s current 5 Gbps chips. Considering a Realtek RTL8126 5 Gbps Ethernet PCIe and M.2 cards can be purchased for around $15, we might end up with similar to RTL8127 cards going for $30 to $40. It’s the same story for RTL8157 5GbE USB 3.0 adapters at about $15. Several cards and motherboards based RTL8127 are expected by Q4 2025, but we will probably get more choices later in 2026.
Thanks to TLS for the photos.
Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.
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I wonder what the idle power consumption is like.
What I find interesting here is that we’re talking about less than 2W for 10GbE over twisted pair. For a long time, 10G RJ45 was cooking your NIC. Thus if they’re now able to improve the phy on that point, other vendors should follow soon. While the transition from 100M to 1G was brutal 20 years ago with all vendors switching to GbE at the same time, 1G to 10G is almost non-existent, and it’s the first period where we’ve seen baby steps instead (2.5G, 5G). So I’m not sure we’ll see more than 10G over twisted pair for a very long while!
Just a technical remark. Realtek does classical chips so those will run 2W for 10 GigE over 4 twisted pairs! Do not mix that with automotive single-pair 10GBASE-T1 specified in 802.3ch-2020
Not sure why you mention 10Gbase-T1 as I was clearly speaking about RJ45 hence 4 pairs.
Indeed, my mistake. Thanks for correction!
It is only in the past few years that even GbE became much the norm, with quite a few Google certified Android TV boxes still carrying only 100M. The transitian was far from overnight and nowhere near 20 years ago.
2.5G and 10G will follow the same age old process of mass implementation.
It has always been baby steps. Just look at USB 2.0, superceded by USB 3.0 a long time ago and yet even top end devices and pretty much all phones in the budget sector still coming with 2.0 in one form or another.
The whole tech idustry has long been about drip drip because profits have to be maintained and with the rise in less companies producing more of what he want, it will continue unabated.
So based upon historical trends I expect 10Gb to be the absolute norm sometime around 2032 and I’m being optimistic about that
I wouldn’t expect 10 Gbps Ethernet to ever become the norm, as most things simply don’t need it. However, at the price point and power usage that Realtek has managed to reach, it will find its way into most NAS devices and most mid-range and up PC motherboards. There was quite some excitement at Computex about this, since the cost is about a third of what the Aquantia/Marvell chips cost and over time, it’s likely to become even lower. A such, 5 Gbps Ethernet is also pretty much dead, whereas 2.5 Gbps is likely to continue to replace 1 Gbps in many devices.
Keep in mind that lower-speed interfaces still serve a purpose, as a faster interface doesn’t offer any useful benefits for a lot of implementations. That said, on something like a phone, USB 2.0 for data is inexcusable, but I don’t see the benefit of going USB 3.0 for a mouse or a keyboard.
Agreed. Also M.2 storage has probably boosted the demand for 10G because file transfers between machines are currently entirely limited by the network. That used not to be the case with SATA for a long time.
I’m not counting the end-user e-waste devices like $20 SBC and android boxes. I was really speaking about what we were seeing on the professional market. I remember in 2001 trying hard to buy a few quad-port 100M NICs that we had validated for our servers, to figure that they were unobtainable, until a vendor asked “but why don’t you take the quad-1000 instead?”. And indeed the new server boards came with on-board GigE and suddenly 100M was impossible to find anywhere. It was replaced absolutely everywhere in less than one year. Simply speaking, any Pentium3 machine was equipped with 100M while P4 machines were on 1G. I think the cause is that at this era there was an expected huge increase in network traffic and once GbE started to arrive at affordable prices, nobody wanted to take the risk to buy 100M anymore. I remember buying a “cheap” pair of GigE cards (DL2000) to upgrade my home connectivity, and a year later, better ones were available for 1/10 of the price.
We’ve not seen this at all with 10G. 10 years ago it was already available on-board for a number of server boards, yet it’s still not the norm. Sometimes 2.5G is found. Rarely 5G and even less 10G. SFP+ is way more common onboard than 10G RJ45. And I really think that heat issues have been the main cause for a while, combined with the fact that most applications simply couldn’t make full use of it (even storage in the SATA era). And who remembers onboard NICs with that huge heat sink on the chip ?
It’s simply because no-one has managed to do what Realtek just announced at the show. I guess some companies didn’t want to, for business reasons, but very few companies are as good as Realtek are, to make more adorable connectivity ICs.
2.5 and 5 Gbps Ethernet are fairly recent additions.
Why people is talking about SATA like SSD’s wouldn’t exist? any decent SATA SSD can bottleneck a 5Gbps NIC, it does not need to be connected to a M2 port. So, even without M2 ports a 10Gbps NAS would make sense, as RAID’s are a thing as well.
Even something like a RAID setup with spinning rust can easily exceed 400 MB/s when doing large sequential transfers to/from a NAS, which far exceeds what 2.5 Gbps Ethernet can cope with, so yeah, if you’re backing up your data or shuffling around photos and videos, 10 Gbps Ethernet is really worth it.
As far as I remember, 2.5G and 5G were born AFTER 10G and the reason they were created was to allow enterprises to deploy wires ethernet at speeds >1G without replacing all their CAT5E wiring infrastructure. This was needed because 802.11ac and 802.11ax with >1Gbps wireless speeds started appearing, and there was a strong need for a LAN standard to support this in a cost effective way.
Correct.
Indeed, not only is 10Gbase-T older than 2.5/5G, *40Gbase-T* is also older than 2.5/5G. Not much — 802.3bq-2016 for 40G was approved in June 2016, vs September 2016 for 802.3bz-2016.
Not that it really matters. I don’t expect to ever see 40Gbase-T hardware on the market. To the best of my knowledge, not a single device with 40Gbase-T has ever shipped. Since it’s not really compatible with existing cat-anything wiring, I can’t see any real reason to use it for anything vs 25/50/100 over fiber. I mean, if you’re going to need to pull new cable/fiber, then why not just pull fiber. It’s probably always going to be cheaper than the weird cat8 for 40G, it’ll last longer, and it’ll allow much higher speeds. The only downside is the lack of PoE for APs, etc.
I have the Realtek 5Gbps PCIe Gen3 1x slot adapter. Linux support is a mixed bag, not all distros have the updated kernel driver notation, so while it passes 4.8Gbps on the switch where it works, some Linux won’t recognize it.
Also no BSD supports this chip natively. A driver exists but errors out on compiling.
I also have the RTL8157 5Gbps USB-C adapter from Wavlink and it *only* works properly in a true USB 3.2 Gen2 port, a Thunderbolt Hub OR a USB4 port. If you stick into your generic USB 3.1 USB-C port, your results and performance may vary. (or it may just hang)
Also the RTL 8157 runs very hot when pushed. If you load it with about 4.8Gbps of traffic for an extended period, the case gets hot.
Regarding lack of support for 5Gbps PCIe, I guess you mean the 8126 ? A friend of mine uses FreeBSD on his Orion O6 with this chip. I remember he had to build the driver which was not enabled by default (or maybe not mainlined?), but it does work for him on FreeBSD.
RTL8157 not the 8126,
OpenBSD also supports RTL8157 natively: https://man.openbsd.org/ure
OpenBSD supports RTL8125 and RTL8126: https://man.openbsd.org/rge.4
Apparently these new chips will be natively supported by the next Linux kernel.
Heatsinks are supposed to get hot?
It worked natively with the latest release from Ubuntu, people always ask me if it gets hot on use, answer here is “yes”. I think they are trying to assess its power consumption. I didn’t take a heatpix of it, but I would guess its the USB bridge chip generating the heat.
For the Windows folks, in Windows 11 & RTL8157 you must use the Realtek driver set via Windows Update, not the native drivers from Realtek.
Realtek did note that a small heatsink is needed, but it’s still not going to be anything like the 10 Gbps solutions to date. How did you find it otherwise?
Looking forward to get something like this!
For now there is huge problem to connect laptop into 10G network, most adapters are big, bulk and runs really hot. With this new chips it should change.
Also we should see new iteration of docking stations with 10G ports. For now there are only few.
Ran into the company that makes the green USB version, some xinese company with a different name and they said their external device could get as hot as 50 degrees C, but they thought that was acceptable due to it’s size… I believe that wouldn’t be allowed in a lot of countries. None on that would be s problem in a dock though, as you couldn’t touch the heatsink inside a dock.
The third mockup is from Winstars/Wavlink: NWU343G is already out for bulk orders (Wavlink was also quick out the retail gate with RTL8157). The big heatsink cases tend to work well.
I think everyone wants to be first on this one. It’ll be interesting to see what the retail pricing will be like.
[ rtl8156b, 2.5Gbps ~$15-20,
rtl8157, rtl8126 5Gpbs, ~$20-30
rtl8261n, 10GBase-T, ~$40 (thx) ]
Maybe in six months to a year, but I think the launch pricing will be higher.
[ those are real prices (1day ago) from the web, USB-RJ45 adapters, and rtl8261n is an example for a SFPplus-RJ45 device; while Jean-Luc is even $5 below for some offers (bargains)?
Compared to (quality) PCIe-(single/dual)RJ45 10G-BaseT (100m for CAT7, ~55m Cat6A, ~30m CAT6, ~22m CAT5(E), but to avoid bundling of cables) from 5-10yrs ago, ~$100;
next between 10G/40GBase-T(4xRx/Tx, ~30m ref-CI 98d1.0/e.g. CAT8), 25GBase-T SG (4xRx/Tx, ~30m CAT8)? (thx) ]