It makes sense comparing Onkyo TX-NR6100 vs Yamaha RX-V485 because they both are able to give some premium features.
A significant difference between the receivers in the number of channels, Onkyo TX-NR6100 has 7.2 versus 5.1 for Yamaha RX-V485. Regarding power, then TX-NR6100 has such a W/Ohm ratio - 100/8, 210/6 when RX-V485 has a power of 80/8, 145/6. The THD is 0.08% for the TX-NR6100 but 0.09% for the RX-V485.
Characteristics of digital to analog converter (DAC) are different, 384 KHz/32-bit for TX-NR6100 and Burr-Brown 384 KHz/32-bit for the RX-V485. Both the TX-NR6100 and the RX-V485 support Bi-amping. Each of the AV receivers can transmit an audio signal directly to the amplifier and bypasses any DSP processing. Rivals from our review have Bluetooth support. The Apple Music service is implemented on considered devices: AirPlay, AirPlay 2. Spotify can be used on each receiver. The TX-NR6100 can work with the audio stream from Deezer, TIDAL, Pandora, SiriusXM, Napster, SoundCloud, and the RX-V485 can receive a content from Deezer, TIDAL, Pandora, Napster, SiriusXM.
HDMI signal transmission in standby mode is implemented in each of the devices. Both rivals can scale the resolution of the incoming HDMI signal. The HDR standard - Dolby Vision is supported by these receivers.
The Onkyo TX-NR6100 has 6/2 HDMI inputs/outputs versus 4/1 HDMI connectors of the Yamaha RX-V485. The HDMI Audio Return Channel (ARC) feature supports both devices. HDMI eARC is available in each model. The Consumer Electronics Control (CEC) feature is present in most modern AV receivers and the models in our comparison are no exception. Both models support the standard HDCP 2.3. The TX-NR6100 has a built-in phono stage for connecting a vinyl player.
Each of the AV receivers from our review supports 2 Multi-room zones. The TX-NR6100 supports voice control via Amazon Alexa, Google Assistant, Siri, Josh.AI, and the RX-V485 - Amazon Alexa, Google Assistant, Siri. It is also worth noting that the ECO mode is presented in each of the receivers. Both TX-NR6100 and RX-V485 can be configured using the Setup assistant.
Only the TX-NR6100 has a Dolby Atmos multichannel audio format support. A surround technology DTS:X is supported only by the TX-NR6100.