Help, internet dls between computers are not making sense

Hello, I just built a computer for the first time as of yesterday and everything is running smoothly except for the internet. The internet seems to be going in and out and it where it will jump up to ~10mbps and then down to ~1mbps and everything in between. I'm running these speed tests through Now what is strange is after each desktop test I run the same test on my laptop (A Macbook Pro equipped with the standard wireless card) and it consistently averages ~14mbps each time regardless of what my desktop is reading.

The wireless card that I'm using in my new desktop is an Asus PCE-N15 and its drivers are fully up to date. I'm not sure what I should do to improve/regularize my internet connection.

*Incase this is of importance, I'm running Windows 8 on my desktop and Windows 7 on my Macbook Pro.