ok. I set the upload on the 4500 to Auto and it shows 2872. to answer your question, my friend has the SBG6120 and the 4500. Also set to Auto and it reads up in the 8000's as he has a faster tier "50 down 8up" in Denver. So , the 4500 does reads it.Also, I get the same 2.65-2.75up running just the modem to PC. the Down stays at 30.55 almost every test. on a side note, I walked with the tech doing the whole new line run to the tap and it was an excellent job with perfect db's and snr.so I know it's not a line issue. however, I do only see 3 channels bonded on DL and 1 on UL.I don't know how many it should be , but my friend in Denver shows 4 bonded on DL and 2 "I belive" on Up"have to dbl check that."