I don't know how better to title my post, but download speeds in any browser on my main PC are very slow. First off, my specs:

HP Envy 700-059cb
Windows 10 (whatever the latest version is for inside preview)
8gb ram
i7 4770

My home network is powered by a Rogers Ignite dual-band wifi modem/router on a 70mb hybrid fiber internet connection. When I connect my desktop PC (the one listed in the specs) to my 5ghz wifi network and run a speed test at speedtest.net, my system usually only gets around 27mb per second. This is less than half of what I feel it should be getting. For example, my little Lenovo Yoga 2 11 also running Windows 10 insider preview when connected to my 2.4ghz network will get roughly 43-45 mb per second while in the same room as my desktop PC. I also have 2 Android devices both connected to the 2.4ghz network which also get around 45mb per second at speedtest. For clarity, when I connect my desktop PC to the 2.4ghz network and do a test on speedtest, my rated download speed drops to less than 20 mb per second. This issue started early in the year and I've been struggling to find a solution since then. I've tried different configurations in the modem/router, different drivers, turning firewall off and on, none of which has helped. Strangely, when I download large well-seeded torrents, my desktop PC will max out at about 8.5-9 MB (megabytes) per second, which is about 70-75 mb (megabits) per second, right around the limit of my internet connection which to me indicates my slow download speeds in browsers isn't a systemwide problem. I've run out of things I can think of to check to solve my problem, can anyone here help me?