My laptop(Asus G75VX) currently has an Atheros ar9485wb-eg that only supports 2.4ghz and is giving me these results http://www.speedtest.net/result/4839602764.png. I'm in Singapore and I'm on a 1gbp/s data plan so the results are not as what I am supposed to get. I'm now wondering if I buy a Asus USB adapter (http://www.amazon.com/Asus-USB-AC56-Dual-band-Wireless-AC1200-Adapter/dp/B00FB45USW/ref=sr_1_16?ie=UTF8&qid=1447766932&sr=8-16&keywords=asus+AC#customerReviews), will it give me better internet connection speed?
Edit: Comparatively, my phone(Sony Xperia Z) is connected via 5ghz and its getting results of 4ms, 91.20 mbps Download and 67.42 mbps upload.