Turning off bluetooth fixed my latency problem. running 8.1 on a Lenovo X1 Carbon (2nd gen).
Bluetooth interferes with the wireless 2.4 Ghz signal. says so on Lenovo's website....
"Bluetooth and Wi-Fi radio are both operating on the same 2.4 GHz band. When both of them are used simultaneously, you may see slower communication speed and/or reduced communication range caused by radio interference."