Roku Express 4K (3940) vs Roku Ultra (4640)

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Express 4K (3940) compared with Ultra (4640)

	RokuExpress 4K (3940)	RokuUltra (4640)
Overview
Released
Released	May 2021	October 2016
Video and audio
Resolution
Resolution	4K	4K
HDR
HDR	HDR10, HDR10+ and HLG (better)	HDR10
Video
Video	Up to 4K at 60 fps (Roku's exact Marlin/3940X developer row); HDCP 2.2 required for 4K/HDR	Up to 4K at 60 fps; HDCP 2.2; upscales 720p and 1080p sources to 4K (Roku launch release reproduced by Display Daily)
HDR
HDR	HDR10, HDR10+ and HLG (Roku's exact Marlin/3940X developer row); no Dolby Vision	HDR10 (Roku's exact Cooper/4640X developer row); Dolby Vision is not supported
Audio
Audio	–	Dolby Digital and Dolby Digital Plus decoding; optical digital audio output for compatible receivers and soundbars (Roku launch release)
Performance
Software
Software	Roku OS	Roku OS
Chip details
Chip details	Arm Cortex-A55; OpenGL ES 2.0 (Roku's exact Marlin/3940X developer row)	Arm Cortex-A53 quad-core 1.2 GHz; OpenGL ES 2.0 (Roku's Cooper/4640X developer row)
Memory
Memory	1 GB (Roku's exact Marlin/3940X developer row)	1 GB (Roku's exact Cooper/4640X developer row)
Storage
Storage	Internal storage serves system/channel use; maker sources used do not publish user-accessible capacity	MicroSD slot provides additional channel storage; USB is for local media playback (Roku launch release). No verified built-in user storage capacity
Software and services
Software and services	Launched with Roku OS 10. App availability varies by region and software version. May 2021 on-sale month is from the exact UK Tech Advisor review; the maker developer table gives only 2021. Cord Busters identifies this model as the UK replacement for Premiere 3920	Roku OS; apps and features vary by region and software version
Connections
Wi-Fi
Wi-Fi	Wi-Fi 5	Wi-Fi 5
Ethernet
Ethernet	No	Yes
Voice remote
Voice remote	No	Yes
Ports
Ports	HDMI output, micro-USB power/compatible Ethernet adaptor connection and reset. No built-in Ethernet socket; USB Ethernet adaptor sold separately	HDMI, Ethernet, optical digital audio output, USB media playback port, microSD slot and power input
Wi-Fi and Bluetooth
Wi-Fi and Bluetooth	Dual-band 802.11ac Wi-Fi (Tech Advisor)	Dual-band 802.11ac MIMO (Roku launch release)
Remote
Remote	Original standard infrared remote with channel shortcuts; no microphone, television power/volume controls or headphone socket. Express 4K+ 3941 includes the voice remote instead	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)
Design
Type
Type	Box	Box
Size
Size	–	4.9 × 4.9 × 0.9 in; fanless design (Tom's Guide)
Power
Power	USB power cable and mains adaptor supplied; use the adaptor if the television USB port provides insufficient power	–
In the box
In the box	Player, infrared remote, batteries, premium high-speed HDMI cable, USB power cable, power adaptor and removable adhesive strip	–