I've recently got installed a line of 300Mbps. The first test was 4 days ago and the real speed was 180Mbps (ookla speed test). However, it's some day that the speed is diminished... a lot! Now the same test, with the same server selected, output something like 30~40Mbps. Doing the same test on windows (same notebook), give a result of 214Mbps! Some update screwed up? How can I revert to the older wireless driver?
I'm on an Asus ROG g750JZ, with Ubuntu 14.04
Below you can find the result of wireless_script, as suggested by @Fabby:
UPDATE:
I don't know if can be of any help, but Win8.1 use the Qualcomm Atheros Wireless Lan Driver, v1.0.37.1274 (... or maybe 10.0.0.287, I'm not sure)