I have a 5+ year old AirPort Extreme Wireless Station (Model A1301, 3rd Generation, Early 2009), and 2 year old MacBook Pro, and a 2 year old home made gaming PC running Windows 8.1.
On my Mac, I get 50Mbps+ download (As confirmed by SpeedTest.net) but on my PC, I can’t get above 15Mbps. This is more of a recent phenomenon, because I never noticed slow ping while playing online games until a couple months ago.
I thought maybe it was the router, so I purchased a Netgear N600. My PC has a Medialink 802.11n USB wireless dongle. I plugged it in and nothing, still the same speeds.
I also tried changing my DNS (to Google’s at 8.8.8.8) but that didn’t help.
My PC is on the other side of the room, but not more than 15 feet away with a direct line of sight. I also tried moving my MacBook Pro right next to the PC and I was still able to get fast speeds on my Mac.
I just ordered another Wi-Fi dongle for my PC, thinking 802.11ac might do the trick.
What else could this be? It is weird because I usually get 30ms ping on my online games but now I’m getting 80ms.
SOLUTION: A new Wi-Fi dongle (dual band) for my PC did the trick. I purchased the Netgear A6200. The funny thing is, I get 50+Mbps with the new dongle + AirPort Extreme but with the Netgear N600 router + Netgear A6200 dongle, I only get 25Mbps using either 2.4GHz or 5GHz.
Best Answer
The Early 2009 AirPort Extreme was a simultaneous dual-band 2x2:2 N device, which did 300Mbps in 5GHz, simultaneous with 144Mbps in 2.4GHz (when operating in 2.4GHz, Apple limits its radios to only use 20MHz-wide channels, to leave room for Bluetooth and other users of the band).
Your PC's Medialink dongle you linked to is 2x2:2, but 2.4GHz only, which means it would only be able to do up to the 144Mbps PHY rate with your AirPort Extreme. Your Netgear N600 AP would have allowed that to go up to 300Mbps max PHY rate, assuming you configured it for 40MHz-wide channels in 2.4GHz, and assuming there wasn't 2.4GHz interference that was killing you.
Overall, based on the information you've provided so far, I would guess that you've got more 2.4GHz interference than before (perhaps from neighbors), and that's killing your 2.4GHz-only Medialink dongle on your PC, but not your 5GHz-capable Mac. It would be interesting to know which band your Mac is connecting on.
It's also possible that one way or another, 802.11 power save mode recently got enabled on your PC, and maybe your PC isn't dealing with 802.11 power save mode well. Check your advanced properties of your Wi-Fi driver on your PC.
Oh, also make sure your AP is set for WPA2-only (AES-CCMP only, no original WPA/TKIP). The RC4 encryption hardware engines underlying WEP and WPA/TKIP can't keep up with 802.11n data rates, so 802.11n requires AES-CCMP encryption or no encryption at all. If you leave old WPA/TKIP enabled, you might accidentally tell your client to join using that kind of encryption, which can force it to use A/B/G data rates because it can't keep up with N, and 15Mbps is a decent real-world throughput when you're limited to A/B/G rates.