How Graphics Processors Switch Between Different Tasks Efficiently
A method for graphics chips to pause and swap between different programs or tasks without waiting for every single part of the processor to finish its current job.
Original patent title: “Context switching using halt sequencing protocol”
A method for graphics chips to pause and swap between different programs or tasks without waiting for every single part of the processor to finish its current job. Granted to Nvidia Corp in 2009 with 14 claims and 6 forward citations, and it is now in the public domain.
Coverage
What does this patent actually cover?
This patent describes a way to pause a graphics processing pipeline so the computer can switch to a different task. Normally, a processor might have to wait for every single unit to finish its work before it can switch tasks, which is slow. This method sends a 'request-to-halt' signal to all units. Each unit reports back whether it is busy, idle, or has successfully paused. Once all units are either idle or paused, a 'stay-halted' signal locks them in place so their current state can be saved to memory and replaced with the state of a new task.
The gap
What does this patent NOT cover?
- Does not cover general-purpose CPU context switching that does not involve a graphics-specific pipeline.
- Does not cover systems that require every unit to be completely idle before initiating a switch.
- Does not cover software-only task switching that lacks the specific hardware 'stay-halted' signal architecture.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Key facts
What made this novel
Instead of waiting for a total system stop, it allows units to enter a 'halted' state—where they stop mid-task but save their progress—allowing the system to switch tasks even when some units are still technically in the middle of an operation.
The Patent Drawing
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Nvidia GeForce graphics cards
GPU-accelerated multitasking in modern operating systems
Graphics drivers managing multiple concurrent applications
Why it matters
The bigger picture
Graphics processors (GPUs) are designed to do many small tasks in parallel. Before this, switching between these tasks was inefficient because one slow unit could hold up the entire pipeline. This patent helped enable modern multitasking on GPUs, allowing the computer to switch between different applications or processes without a noticeable stutter in graphics performance.
Filed
October 18, 2005
Granted
March 31, 2009
Market context
Who's building on this
Companies in this space
Nvidia continues to build on this foundation in their modern GPU architectures, such as the Ada Lovelace and Blackwell series. Other major GPU manufacturers like AMD and Intel use similar concepts to manage state transitions in their own parallel processing pipelines.
Market impact
This patent helped solidify the technical requirements for high-performance GPU multitasking. By enabling faster context switching, it allowed GPUs to move beyond simple rendering and become the versatile parallel processors that now power modern gaming, professional rendering, and large-scale AI training.
Claim 1 — Plain English
What this patent covers
This patent describes a way to pause a graphics processing pipeline so the computer can switch to a different task. Normally, a processor might have to wait for every single unit to finish its work before it can switch tasks, which is slow. This method sends a 'request-to-halt' signal to all units. Each unit reports back whether it is busy, idle, or has successfully paused. Once all units are either idle or paused, a 'stay-halted' signal locks them in place so their current state can be saved to memory and replaced with the state of a new task.
The clever bit
Instead of waiting for a total system stop, it allows units to enter a 'halted' state—where they stop mid-task but save their progress—allowing the system to switch tasks even when some units are still technically in the middle of an operation.
What it does not cover
- Does not cover general-purpose CPU context switching that does not involve a graphics-specific pipeline.
- Does not cover systems that require every unit to be completely idle before initiating a switch.
- Does not cover software-only task switching that lacks the specific hardware 'stay-halted' signal architecture.
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
Patent enters public domain
This patent is in the public domain
See the Freedom to Build guide — what is free to use, what is not, and how to cite this patent.
PatentBrief Score
Impact Score
Early stage
Citation count
17/40
Early citations
Claim breadth
9/20
Moderate scope
Recency
5/20
Granted 10–20 years ago
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$12K – $37K
Midpoint $23K · expired or expiring · industry ×1.6
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Patent Claims
0 independent claims · 1 dependent
Claims are the legal boundaries of the patent. An independent claim stands alone. A dependent claim adds limitations to its parent, narrowing — but not broadening — the scope.
The original legal language
Original claims
14 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Garlick, B. J., Silkebakken, R. A., Shebanow, M. C., & Keller, R. C. (2009). How Graphics Processors Switch Between Different Tasks Efficiently (U.S. Patent No. 7,512,773). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/7512773/context-switching-using-halt-sequencing-protocol
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does How Graphics Processors Switch Between Different Tasks Efficiently cover?
A method for graphics chips to pause and swap between different programs or tasks without waiting for every single part of the processor to finish its current job.
Who owns patent US 7512773?
Nvidia Corp owns this patent, granted in 2009.
When does this patent expire?
This patent has expired and is now in the public domain — anyone can use the invention freely.
What is patent US 7512773 cited by?
This patent has been cited by 6 later patents that build on its ideas.
What problem does this patent solve?
Graphics processors (GPUs) are designed to do many small tasks in parallel. Before this, switching between these tasks was inefficient because one slow unit could hold up the entire pipeline. This patent helped enable modern multitasking on GPUs, allowing the computer to switch between different applications or processes without a noticeable stutter in graphics performance.
What does this patent NOT cover?
Does not cover general-purpose CPU context switching that does not involve a graphics-specific pipeline.
Same assignee
More from Nvidia Corp
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