Gigabit Network Adapters

First, thanks to all that contribute to this thread.
All input is greatly appreciated.

I have a dilema regarding the upgrade of a NIC and I’m a bit confused.

I have a home network setup with all workstations running 10/100 network cards connected to a 10/100 Linksys Router.
All 10/100 data transfer are Full Duplex.

With the emergence of Windows Vista, I have discovered that the finicky TCP/IP stack is not compatible with NICs with the RealTek RTL8139 chipset. The bottom line is that there has simply been no Internet connectivity since Vista 5308 Beta.

I am now forced to replace the network card in this workstation in order to achieve Vista Internet connectivity.
Looking towards the future, I thought I would purchase a Gigabit 10/100/1000 NIC as a replacement.
However, my observation is that all of the Gigabit NICs that I have researched will only run at Half Duplex at the 10/100 speeds. Full Duplex is only achieveable at the 20/200/2000 speeds.

My question is, how will this affect data transfer on a network where all the other components are Full Duplex at 10/100?

Thanks for the inputs.

It won’t
The card will lower its speed to 10/100 as long as it comunicates with a 10/100 nic


I understand that when set to Auto Detect the components will default to 10/100, but I’m concerned about the duplex mismatch and the effects that it would have on the rest of the network.

Since unmanaged switches like the one built into the Router are generally configured to Auto Detect and can’t be changed, will it Auto Detect and default to the Half Duplex speed of the Gigabit NIC, thus making the entire network Half Duplex?

R u sure that the new nic runs half duplex at 10/100?
I have a couple of onboard gig nics that drop to 10/100 to full duplex

Normally if the router is set to auto negotiate it will configure only the port that comunicates with the nic to HD thus the HD NIC will comunicate with the FD NIC at HD speed and the FD nic to FD speed to any other FD NICS in the network

Actually, 20/200 is just marketing bull for 10/100 at full duplex. I’m 90% sure that if the rest of your network is running at “20/200” (10/100 at full duplex) that it should all be fine.

They will of course run FD in 10/100, I would recommend you to get Intel NIC instead of shitty Realtek but that’s up to you.

Thanks everyone.
Research has revealed that [B]Chriso[/B] is correct. There is no 20/200/2000, it is simply 10/100/1000 at Full Duplex.

DiiZzy, you are the second recommendation for an Intel NIC and I’m starting to think that I should invest the extra cash and go that way.

I appreciate all the input.
You have all clarified this issue.

Time to go shopping.


No problems, I ran into this marketing “scam” only a couple of weeks ago when setting up a switch (still not sorted it yet, but that’s another problem).