How to tell if phone is connecting with b or g speeds in wifi

[tokuzumi]

I have the speedtest.net app installed on the phone, and have wifi turned on. Mobile network is turned off. Router is a g capable router. The phone results are about 2.6 mb/s download, and 650 k upload. Testing a pc on the same test results in speeds of 8.5 download, and 1.5 upload. The test was done with the phone and the computer in the same room, same distance from the wireless router. This makes me think the phone is connecting via b speeds, and not g. I thought the hero was capable of wireless g speeds over wifi? While my results are still faster than what I usually get on Sprint, I'm not complaining too much, but wanted to see if you folks noticed the same thing, or not.

Edit: I'm running the stock sprint 1.56 rom, non-rooted