CalculatorsGPU vs VR Headset Bottleneck
Will the NVIDIA GeForce RTX 4090 run the Valve Index?
The RTX 4090 is the reference score of 100, with 24 GB of GDDR6X, about 82.6 TFLOPS and a 450 W board power. The Valve Index is 1440×1600 per eye at 144 Hz, about 108° horizontal, a DisplayPort tether, SteamVR base stations, and 809 g.
GeForce RTX 4090 has spare headroom on the Index
Score 100 against a minimum of 40 is a headroom of 2.50. 24 GB of GDDR6X leaves 16 GB against a 8 GB budget for 1440×1600 at 144 Hz.
There is spare score and spare memory. The limit is the panel and the link, not this graphics card.
GeForce RTX 4090 is about 82.6 TFLOPS at 450 W. The 8 GB figure is the framebuffer budget for 1440×1600, not a number printed on the headset.
The Index is 809 g, about 108° horizontal, connected by DisplayPort tether, with SteamVR base stations.
Inputs
Results
- Score headroom
- 2.50
- VRAM budget
- 8 GB
- VRAM spare
- 16 GB
- Verdict code
- 3
Related gear
- Current-gen GPU with 16 GB or more
High-resolution headsets spend the spare gigabytes before they spend the score.
$500–$2000
- DisplayPort or Link cable rated for the headset
A streamed headset still needs a cable or a clean Wi-Fi path that can hold the refresh.
$30–$80
How the number is made
Headroom is the GPU score divided by the headset minimum. VRAM starts at 8 GB under 3 megapixels per eye, 10 GB under 5.5, 12 GB under 7.5, otherwise 16 GB. At 120 Hz or more, panels of at least 5 megapixels add 2 GB. Short means the score or the VRAM misses. Tight means headroom under 1.15 or fewer than 4 GB spare. Excess means headroom of at least 1.45 and at least 8 GB spare. Anything between is comfortable.
The score is a relative sim-racing index, not a published TFLOPS chart. The VRAM steps are a planning budget for the framebuffer, not a vendor requirement.
- Score headroom. 1.00 means the GPU matches the headset minimum exactly.
- Verdict code. 0 short, 1 tight, 2 comfortable, 3 spare headroom.
What the pair pages add
Each GPU × headset URL repeats the same formula in the HTML, then names that card’s TFLOPS, memory type and board power next to that headset’s connection, tracking and weight. The parent form is the hub; the pair is the purchase question.
Related calculators
- VR Pixels per Degree
A GPU that holds the frame can still leave a soft picture if the panel has few pixels per degree.
- USB Hub Power for a Sim Rig
A streamed headset and a button box often share the same powered hub.
- Triple Screen FOV and Angle
When the headset is short on score, a triple is the other way to fill the view.
Questions
Does a higher score always mean a locked refresh?
No. A score above the minimum can still be tight on VRAM, and a huge score on a small panel is spare headroom rather than a harder image.
Why does the Crystal ask for more VRAM than the Index?
2880×2880 at 120 Hz crosses both the 7.5 megapixel step and the high-refresh adder. 1440×1600 stays in the 8 GB band even at 144 Hz.
Is the Quest number for standalone or PCVR?
PCVR. The minimum score is for driving the panel from the PC, not for the mobile chipset.