I'm using WinXP SP2.
My experience with it has been mixed.
Generally my
lag has been reduced. Where before I'd get a hiccup or stutter when playing the game with my onboard NIC that went away.
Network wise I think I shaved about 10ms off of my latency. If you run WireShark on XP while the KillerNIC is in LLR Game Mode (Lag & Latency Reduction) you will see nothing.
Total blankness.
The Windows network stack is completely bypassed when in that mode. Any CPU overhead your onboard NIC would have is eliminated. Yes, I know that modern processors can handle a TON of calculations, but when reassembling TCP or UDP packets you can run into cases where Windows is overriding the game to get those packets taken care of.
Those cases are removed.
In addition you are using the LINUX network stack, which as I understand is superior to Windows.
There are applications that can be added to the Linux distro on the KillerNIC. I have their onboard firewall running (I think it runs iptables).
There are also
other FNA applications that can be installed on the card. I don't use the other ones, but the new driver includes a packet prioritization application. I'm looking forward to working with that.
So essentially I am behind two hardware firewalls (Router and KillerNIC) and will have multi-tiered packet prioritization at both my PC level and external facing network level.
There are, however, some people that just done see any difference whatsoever. It also depends on what game you are running. I play World of Warcraft and that has consistently had the best improvements of all games. Look around on the internet for more information on that.
Other games are not as dramatically improved. Your mileage may vary.
A friend of mine plays Everquest 2. He bought the lower end card and couldn't stop raving about his performance improvements. This drove me to buy the thing. I'd buy one again if I had reason to.
If you have cash burning a hole in your pocket, check the thing out. I'd recommend the one with the silly heatsink and faster CPU, but that is just me.