Roku Ultra (4640) vs Roku Ultra (4660)

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Ultra (4640) compared with Ultra (4660)

	RokuUltra (4640)	RokuUltra (4660)
Overview
Released
Released	October 2016	October 2017
Video and audio
Resolution
Resolution	4K	4K
HDR
HDR	HDR10	HDR10
Video
Video	Up to 4K at 60 fps; HDCP 2.2; upscales 720p and 1080p sources to 4K (Roku launch release reproduced by Display Daily)	HD, 4K and 4K HDR at up to 60 fps; protected 4K requires HDCP 2.2 (Roku launch release and original 4660 comparison chart)
HDR
HDR	HDR10 (Roku's exact Cooper/4640X developer row); Dolby Vision is not supported	HDR10 (Roku's exact Bryan/4660X developer row); no Dolby Vision in the original 4660 comparison chart
Audio
Audio	Dolby Digital and Dolby Digital Plus decoding; optical digital audio output for compatible receivers and soundbars (Roku launch release)	Dolby Audio and DTS passthrough over HDMI; night listening mode (Roku's original 4660 comparison chart). Optical output removed from the previous 4640 model
Performance
Software
Software	Roku OS	Roku OS
Chip details
Chip details	Arm Cortex-A53 quad-core 1.2 GHz; OpenGL ES 2.0 (Roku's Cooper/4640X developer row)	Arm Cortex-A53; OpenGL ES 2.0 (Roku's exact Bryan/4660X developer row); quad-core confirmed by the original 4660 comparison chart. Clock speed unpublished
Memory
Memory	1 GB (Roku's exact Cooper/4640X developer row)	1 GB (Roku's exact Bryan/4660X developer row)
Storage
Storage	MicroSD slot provides additional channel storage; USB is for local media playback (Roku launch release). No verified built-in user storage capacity	microSD adds channel storage and can improve channel loading; not local media playback. Use the USB media port for supported local files
Software and services
Software and services	Roku OS; apps and features vary by region and software version	Roku OS; apps and features vary by region and software version
Connections
Wi-Fi
Wi-Fi	Wi-Fi 5	Wi-Fi 5
Ethernet
Ethernet	Yes	Yes
Voice remote
Voice remote	Yes	Yes
Ports
Ports	HDMI, Ethernet, optical digital audio output, USB media playback port, microSD slot and power input	HDMI, Ethernet, microSD, USB media port and power input; no optical audio output
Wi-Fi and Bluetooth
Wi-Fi and Bluetooth	Dual-band 802.11ac MIMO (Roku launch release)	802.11ac dual-band MIMO (Roku's original 4660 comparison chart)
Remote
Remote	Original point-anywhere remote has voice search, headphone jack, headphone volume, gaming buttons and lost-remote finder; no TV volume or power control (The Next Web)	Original voice remote with television power and volume buttons, headphone socket, gaming buttons and lost-remote finder. Television controls require a compatible television; no later personal shortcut buttons
Design
Type
Type	Box	Box
Size
Size	4.9 × 4.9 × 0.9 in; fanless design (Tom's Guide)	Approximately 5-inch-square box (Tom's Guide)