Without a GPU it isn't quite that simple, but thank you for trying to help.  I can't remember if I have a spare video card lying around, but if I do I will look further into it.  Otherwise I'll just live with it as is for now.  Thanks.

I'm happy to say I figured out the issue.  For whatever reason something wasn't happy with both the motherboard ethernet and the new NIC installed.  I did manage to find an old GPU I could put in the box so I could do some investigating, and the first thing I tried was disabling the onboard ethernet to see if that might be enough.  Luckily it was just the ticket.  Fired up the machine and it showed 1.0 Gbps at the switch at first, but once the OS started booting and hardware drivers started getting loaded, when it got around to the driver for the NIC the light went out on the switch and shortly afterwards came back on but showed a 2.5 Gbps connection.  I'm glad it was as simple as that.  Thanks again for your time anyway.

3 hours ago, _Shorty said:

I'm happy to say I figured out the issue.  For whatever reason something wasn't happy with both the motherboard ethernet and the new NIC installed.  I did manage to find an old GPU I could put in the box so I could do some investigating, and the first thing I tried was disabling the onboard ethernet to see if that might be enough.  Luckily it was just the ticket. 

Was that onboard NIC a RealTek 1gbs unit?   If it was, I suspect that it was detected first and the 1gbs driver for that unit was installed .  Then, when the 2.5gbs NIC on the card was detected, the software 'said', "I have already installed a RealTek driver and this NIC can use that one."  (If I recall correctly, this is what use to happen when these 2.5gbs NIC were first added as onboard NIC's.  What I don't know is if the 1gbs NIC's will work with the 2.5gbs driver...)

No, Nvidia NIC, if I remember.  It's a pretty old AMD system with an Nvidia chipset. AMD Phenom™ II X4 965 CPU, ASUS M3N72-D motherboard with NVIDIA nForce 750a SLI chipset.  The CPU and the Realtek 2.5 Gbps were only giving me about 800 Mbps while maxing out one of the cores, haha.  So for now I went back to the Nvidia NIC, as it offloads enough from the CPU to max out its 1 Gbps.  But at least it is another reason to upgrade that machine to something newer with an NVMe SSD for cache.  At least I have a 2.5 Gbps NIC that I know will work if whatever I get doesn't already have a 2.5 Gbps port built in. The Realtek seems to have a larger software component that the old CPU just can't crunch through quickly enough to make it worthwhile to use in that old machine. 

now its almost 2024, is the Realtek RTL8125BG now working with 2.5G ? i want to buy a Mainboard, with this chip on it

12 hours ago, eLpresidente said:

now its almost 2024, is the Realtek RTL8125BG now working with 2.5G ?

It works, the in tree driver can have some issues for some, including a new one with the new kernel in v6.12.5, where it doesn't work with jumbo frames, but there's an alternative driver included with the Realtek driver plugin that works better for some and still works with 6.12.5 and jumbo frames.

On 12/1/2023 at 11:22 AM, JorgeB said:

It works, the in tree driver can have some issues for some, including a new one with the new kernel in v6.12.5, where it doesn't work with jumbo frames, but there's an alternative driver included with the Realtek driver plugin that works better for some and still works with 6.12.5 and jumbo frames.

Thanks for your quick response.. is the first or the last one the right one.. i think you can use both? 

 

36 minutes ago, eLpresidente said:

Thanks for your quick response.. is the first or the last one the right one.. i think you can use both? 

 

Click in the 'Info' button and choose the proper one based on the chip set(s) supported and the chip set that you have in your server...

1 hour ago, eLpresidente said:

is the first or the last one the right one.

For the r8125 it's the first one

3 hours ago, JorgeB said:

For the r8125 it's the first one

Thx JorgeB

On 12/6/2023 at 3:49 AM, eLpresidente said:

Thx JorgeB

Hey, how this RTL8125BG working for you? Any issues?
I am thinking of upgrading my mobo but choices with intel nic are pretty limited in my area. 

1 minute ago, fishermanG said:

Hey, how this RTL8125BG working for you? Any issues?
I am thinking of upgrading my mobo but choices with intel nic are pretty limited in my area. 

I have no issues.. but I also don't use jumbo frames.. but many people don't recommend it.. they recommend Intel.. but I have has problems with Intel.. so it's up to you.. I don't even use the community plugin drivers for realtec and it worked fine for me

4 minutes ago, eLpresidente said:

I have no issues.. but I also don't use jumbo frames.. but many people don't recommend it.. they recommend Intel.. but I have has problems with Intel.. so it's up to you.. I don't even use the community plugin drivers for realtec and it worked fine for me

Thanks for the reply. Are you able to achieve low c-state with this nic if you happen to have measured before?

I know this is an older thread, but it came up first in my search for unRAID 2.5gbe.

 

Someone mentioned the Intel X540 chip earlier in the thread. The Intel x540 chip is either 1Gbe or 10Gbe. It can't negotiate 2.5 or 5Gbe.. the Intel X550 chip *does* handle 1, 2.5, 5, and 10Gbe.

 

Also, for people with SFP+ ports. The ports themselves only speak 10Gbe. To use anything other than that, you need a proper transceiver for handling multi-gbe properly. If you intend to use an SFP+ port for 2.5Gbe, you *need* a transceiver module that is 2500BASE-T capable, so choose your transceiver modules wisely.