Qualcomm Snapdragon 835

Qualcomm Snapdragon 835
Information
Type	Mobile system on a chip (used as the compute platform for first-generation standalone VR/AR headsets)
Developer	Qualcomm
Operating System	Android, Windows
Devices	Oculus Quest (first generation), HTC Vive Focus, Lenovo Mirage Solo
Release Date	Announced November 17, 2016; shipping in devices from 2017
Website	https://www.qualcomm.com/products/mobile/snapdragon/smartphones/snapdragon-8-series-mobile-platforms/snapdragon-835-mobile-platform

Qualcomm Snapdragon 835 (model number MSM8998) is a mobile system on a chip that Qualcomm announced on November 17, 2016 and shipped in devices through 2017. It was the flagship Android phone processor of its generation, but it matters to VR and AR history for a different reason: before dedicated extended reality chips existed, the 835 was the part that made the first wave of self-contained, no-PC, no-phone headsets possible. The original Oculus Quest, the HTC Vive Focus, and the Lenovo Mirage Solo all ran on it.

To make the point a little sharper: when people talk about the first generation of standalone VR, they are mostly talking about hardware built around this one phone chip. Qualcomm had not yet split off a separate XR product line, so headset makers took the same silicon that went into the Samsung Galaxy S8, the Google Pixel 2, and the OnePlus 5, and bolted a VR shell around it.

What it is

The Snapdragon 835 was the first mobile platform to ship commercially on a 10nm FinFET process, fabricated by Samsung. Qualcomm said the smaller node let the chip run 35 percent smaller and draw about 25 percent less power than the Snapdragon 820 and 821 it replaced, which is exactly the kind of efficiency a battery-powered headset strapped to your face wants.

The CPU is an octa-core Kryo 280 design. Qualcomm built it under ARM's then-new "Built on ARM Cortex Technology" licensing program, which let it take stock ARM cores and modify them: four semi-custom Cortex-A73-based performance cores clocked up to 2.45 GHz, paired with four Cortex-A53-based efficiency cores at up to 1.9 GHz in a big.LITTLE arrangement.

Graphics come from the Adreno 540 GPU, which Qualcomm rated at roughly 25 percent faster 3D rendering than the Adreno 530 in the 820 series and which supports OpenGL ES 3.2, OpenCL 2.0, Vulkan, and DirectX 12. Rounding out the package: a Hexagon 682 DSP for sensor fusion and machine learning, a Spectra 180 image signal processor with dual 14-bit ISPs, a Snapdragon X16 LTE modem rated up to 1 Gbps downlink, dual-channel LPDDR4x memory, and Bluetooth 5.0. The DSP and ISP turn out to matter a lot for VR, because that is where the headset's camera and motion-sensor work happens.

Why it mattered for VR

Qualcomm did not stumble into VR by accident. The official 835 product brief literally put a headset icon on the page under the heading "Putting the 'real' in virtual reality," promising "superior virtual and augmented reality with immersive visuals, heightened 3D sounds, and intuitive interactions, with less of the lag or latency that causes motion sickness." The company was telling OEMs, from day one, that this chip was meant for headsets as well as phones.

It backed that up with hardware. On February 23, 2017, Qualcomm announced the Snapdragon 835 VR Development Kit (VRDK), a standalone all-in-one head-mounted display reference design built around the 835, sold to developers through the Qualcomm Developer Network. The kit demonstrated the techniques that would define standalone VR for years: six degrees of freedom (6DoF) inside-out motion tracking, eye tracking with foveated rendering, predictive head positioning run on the Hexagon DSP, and a WQHD (2560 x 1440) AMOLED display. Cristiano Amon, then executive vice president at Qualcomm Technologies, framed the bet plainly: "We see great potential for the exciting new experiences made possible by truly mobile, untethered virtual reality."

The reason 6DoF on a phone chip was a big deal is worth spelling out. Tracking your position in a room without external sensors means crunching camera and inertial data continuously at low latency, and doing it without a wall outlet or a tethered PC doing the heavy lifting. The 835 had enough CPU, GPU, and DSP headroom to pull that off inside a battery and thermal budget you could wear. That is the capability that separated standalone headsets like the Quest and Vive Focus from the earlier phone-slot viewers (Samsung Gear VR, Google Daydream View) and from the 3DoF-only Oculus Go.

Devices that used the Snapdragon 835

Each of these has been verified individually against its own source.

Device	Type	Released	Notes
Oculus Quest (1st generation)	Standalone 6DoF VR headset	May 2019	Confirmed by Oculus at Oculus Connect 5. Unlike the passively cooled Go, the Quest added an internal fan for active cooling to sustain the 835 under VR load.
HTC Vive Focus	Standalone 6DoF VR headset	December 2017 (China); November 2018 (international)	4 GB RAM, AMOLED display at 2880 x 1600 total, 6DoF "world-scale" inside-out tracking from two front cameras.
Lenovo Mirage Solo	Standalone 6DoF VR headset (Google Daydream)	May 2018	The first standalone Daydream headset. 4 GB RAM, 64 GB storage, QHD LCD at 2560 x 1440, Google "WorldSense" inside-out 6DoF tracking.

Devices that are often confused but did NOT use the 835

A couple of near-contemporaries get lumped in with the 835 standalones and should not be.

• Oculus Go ran the older Snapdragon 821, not the 835. The Go shipped with a Snapdragon 821 (quad-core, paired with an Adreno 530 GPU) and only did 3DoF rotational tracking, which is part of why it was cheaper and less capable than the Quest that followed it.
• Samsung HMD Odyssey is a Windows Mixed Reality headset that tethers to a PC over USB and HDMI. It has no onboard mobile SoC at all; the PC does the rendering, so it is not a Snapdragon 835 device in any sense.

Relationship to dedicated XR chips

The 835 era was a stopgap, and Qualcomm knew it. Using a phone chip for VR meant living with a part that was not designed around the specific demands of head-worn displays. So in 2018 Qualcomm split XR off into its own product line.

The Qualcomm Snapdragon XR1, announced May 29, 2018, was billed as the world's first chip purpose-built for extended reality rather than a repurposed smartphone SoC. It targeted the entry to mid tier and AR glasses. The flagship-class follow-up came on December 5, 2019: the Qualcomm Snapdragon XR2, the first 5G XR platform, which Qualcomm rated at roughly twice the CPU and GPU performance of its prior XR platform and which added support for up to seven concurrent cameras and 3K-per-eye displays at 90 Hz. The XR2 is what powered the Oculus Quest 2, which is the clearest illustration of the handoff: the first Quest used a borrowed phone chip, the second used silicon designed for the job.

Specifications

Feature	Snapdragon 835 (MSM8998)
Announced	November 17, 2016
In devices from	2017
Process node	10nm FinFET (Samsung)
CPU	Octa-core Kryo 280: 4x semi-custom Cortex-A73-based up to 2.45 GHz + 4x Cortex-A53-based up to 1.9 GHz
GPU	Adreno 540 (OpenGL ES 3.2, OpenCL 2.0, Vulkan, DX12)
DSP	Hexagon 682
ISP	Spectra 180 (dual 14-bit ISPs)
Modem	Snapdragon X16 LTE, up to 1 Gbps downlink (LTE Cat 16)
Memory	LPDDR4x, dual channel
Connectivity	802.11ac and 802.11ad Wi-Fi, Bluetooth 5.0
Notable VR/AR use	Oculus Quest (1st gen), HTC Vive Focus, Lenovo Mirage Solo, Snapdragon 835 VR Development Kit

See also

• Snapdragon 835 VR Development Kit
• Qualcomm Snapdragon XR1
• Qualcomm Snapdragon XR2
• Oculus Quest
• Standalone VR headset