10Gtek ASF-10G-T 10Gbase-TX SFP+ to 10Gbase-T Module Review

10GTek ASF 10G T 10Gbase TX Label
10GTek ASF 10G T 10Gbase TX Label

We now have our tenth SFP+ to 10Gbase-T review and the first after our SFP+ to 10Gbase-T Adapter Module Buyers Guide. The 10Gtek ASF-10G-T or 10Gbase-TX module has multiple model names. We are using what is on the package, however, the Amazon listing we purchased these from have a product that says “10Gtek 10G-SFP-T” and that it is coded for Cisco SFP-10G-SR even though it is being marketed as a “For Intel” and open switches. As we have found in this series, simple features such as naming consistency are often overlooked on these products.

The module is rated to convert a SFP+ slot to a RJ45 10Gbase-T slot and span up to 30m of cable distance. We are going to see how it stacks up in our review.

10Gtek ASF-10G-T 10Gbase-TX SFP+ to 10Gbase-T Converter Overview

We purchased our 10Gtek ASF-10G-T or 10Gbase-TX from Amazon. Perhaps the most unique item about this module is the packaging. After nine units we had received simple white packaging every time. This is the first unit where we had something decidedly upscale with a metal casing, protective foam, and even a small manual. You will notice the packaging calls this a “10Gbase-TX” model.

10GTek ASF 10G T 10Gbase TX In Packaging
10Gtek ASF 10G T 10Gbase TX In Packaging

On this module, we have markings which many of our other modules did not have. The “ROHS” marking was interesting as an example since the official marking is normally noted as “RoHS”. That type of inconsistency seems to be common for these modules. One nice feature is that we have a barcode for inventory management which is a step up from many of the other labels we have seen.

10GTek ASF 10G T 10Gbase TX Label
10Gtek ASF 10G T 10Gbase TX Label

You can see that the on-label model number is “ASF-10G-T” which we saw on other modules such as in our HiFiber SFP+10GBASE-T ASF-10G-T and Ipolex ASF-10G-T reviews.

One end of the module is the RJ45 port. We actually managed to get lighting inside the port (finally.)

10GTek ASF 10G T 10Gbase TX RJ45 Port
10Gtek ASF 10G T 10Gbase TX RJ45 Port

These units plug into switch SFP+ ports and can provide up to 10Gbase-T connectivity at 30m. A feature we have noticed doing these reviews is that the PCBs tend to be different near the SFP+ connector. This tells us that we are testing modules with some level of uniqueness not just the same unit every time with a different label.

10GTek ASF 10G T 10Gbase TX SFP PCB
10Gtek ASF 10G T 10Gbase TX SFP PCB

Overall, the unit looks like a SFP+ to 10Gbase-T transceiver. This is a similar casing to many modules we have seen in the past. We like that the SFP+ and 30m (“30-m”) distance limit at 10Gbase-T speeds specs are printed directly on the label. That is always helpful when one is looking through a set of spares. The unit also has a “For INT” on its label which tells us this is an Intel module, even though the listing for the unit notes “Coding as Cisco SFP-10G-SR.” We tested it with MikroTik, Netgear, and QCT switches as well and the modules worked.

10Gtek ASF-10G-T 10Gbase-TX Nbase-T Support

As we mentioned earlier, the official spec says this is simply a SFP+ to 10Gbase-T converter for distances up to 30m. There is no mention of Nbase-T, 2.5Gbase-T, 5Gbase-T, 2.5GbE, or 5GbE in the specs, nor on the device or its contents. We have now found some SFP+ to 10Gbase-T converters support Nbase-T while others like the QSFPTEK, 6COM and ADOP units do not.

First, we tried the 10Gtek unit in a MikroTik CRS326-24S+2Q+RM Switch connected to an Aquantia AQtion 10Gbase-T adapter on a 20m CAT6 cable we had:

10GTek ASF 10G T 10Gbase TX 10gbps Speeds
10GTek ASF 10G T 10Gbase TX 10gbps Speeds

As you can see, we linked at 10Gbase-T speeds without issue.

We then selected a 5Gbps rate on the Aquantia AQtion NIC and again, we saw a 5GbE link:

10Gtek ASF 10G T 10Gbase TX 5gbps Speeds
10Gtek ASF 10G T 10Gbase TX 5gbps Speeds

We then swapped NICs just to get some diversity and used the TRENDnet TEG-25GECTX 2.5GbE adapter using the Realtek RTL8125. We also verified this with the Syba 2.5 Gigabit Ethernet PCIe NIC that uses the same controller.

10Gtek ASF 10G T 10Gbase TX 2.5gbps Speeds
10Gtek ASF 10G T 10Gbase TX 2.5gbps Speeds

Here we saw a 2.5Gbps link as we expect. The 2.5GbE and 5GbE results were something we were hoping to see but we did not find explicitly mentioned. Other units such as the Wiitek, MikroTik, FlyFiber, FiBay, and Ipolex units, support 2.5Gbps and 5Gbps network speeds without the features being explicitly mentioned.

We also received requests to test jumbo frames on these modules so we have started to do that. This module, as we expect worked and we are now 10 of 10 with these modules supporting jumbo frames. That is expected but we did verify it works.

10Gtek ASF-10G-T 10Gbase-TX Performance

We ran a few NAS tests to a SFP+ SSD NAS from a workstation with a 2.5/5/10Gbase-T adapter as well as a SFP+ adapter to see the impact of the 10Gtek ASF-10G-T or 10Gbase-TX has running in a MikroTik CRS309-1G-8S+IN switch.

10Gtek ASF 10G T 10Gbase TX Performance
10Gtek ASF 10G T 10Gbase TX Performance

Here we find a unit that is at the higher-end of our performance scale. It is also slightly faster than the three units that did not support Nbase-T speeds. In our buyer’s guide, we found that there seems to be a pattern with the modules supporting 2.5GbE and 5GbE speeds running slightly faster. For those wondering we were getting a 0.6-1Mbps faster rate on most of these versus the Wiitek unit, but it was essentially even in terms of performance.

Final Words

Most of these modules seem to be relatively similar to the Mikrotik S+RJ10 in terms of capabilities and performance, except for the three that do not support 2.5GbE and 5GbE speeds. All ten units run very hot in switches because they are using what is relatively a lot of power in the 2-3W range each.

With 2.5GbE and 5GbE support, the 10Gtek module is very versatile. We have found several similar modules that do not have this capability. Jumbo frames seem to be a feature that all of these modules support.

Pricing is generally on the higher end of the spectrum with this unit in the $59.99 range. With what we have seen, differentiation is effectively the serial number on the label along with the nice packaging. We think that may not be worth a 20%+ premium over competitive offerings.

Overall, this unit performed well and came with great packaging which differentiates the unit from others we have tested. We will update our SFP+ to 10Gbase-T module buyer’s guide as we get a few more units tested.


  1. SFP+ 10G module compatibility when working in 1G mode may actually be problematic, so perhaps the review/buyers guide should include results for that? Some Intel 85299EB firmware for embedded NIC’s can be quite cranky about modules, especially if the OEM sticks their hands into it (looking at you Supermicro).

  2. Are the 2.5 GbE and 5 GbE speeds compatible with other SFP+ switches other than Mikrotik? Looking for a switch currently to add to 10 GbE to my NAS and workstation and my router has a 2.5 GbE Lan port. Would this feature work in an Ubiquiti SFP+ port?

  3. I have a pair of these in a UDM-Pro. One is connected to the onboard 10G nic in my NAS, the other is connected to the onboard 2.5G nic in my main system.

    The 10G connection seems to be working fine, but with the 2.5G connection I get full 2.5G up, but only around 200Mbps down.
    Iperf: https://ss.brandon3055.com/194f6
    I have also tested with a couple different 1G systems and I see the same issue. 1Gbps up and ~200Mbps down.

  4. I think it would be good if you listed the NIC’s that are used for each SFP. It seems some issues are related to interoperability issues between different NIC’s in different speeds. (Autonegotiation.)


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