Video · Practical guide

TouchDesigner: GPU output, Video Device Out and Sync II reference

Identify the image output path before changing a synchronization control. A GPU window and a video-card output have different settings and states. This guide uses the Latest Window COMP and Video Device Out TOP documentation and the October 2020 Quadro Sync II v04 manual. Check the actual build, driver and equipment separately.

Distinguish desktop, GPU and Video Device Out paths

A custom resolution alone does not establish a Sync II requirement or a rule for every GPU and output path.

The official Window COMP and Video Device Out TOP pages were in Latest, with visible last edits on July 22, 2026 at 17:39 and July 28, 2026 at 14:05. Their permanent links identify revisions 38382 and 38393. We record those numbers as metadata for the pages reviewed without claiming to have read the archived revision URLs. The installed build in the actual setups was not verified.

The NVIDIA Quadro Sync II manual is edition DU-08348-001_v04, October 2020: printed pages 1, 7, 22, 23, 28 and 31. It applies to Quadro Sync II; Quadro G-Sync II has separate documentation. Also check compatibility with the installed drivers.

Window COMP: monitor, window and V-Sync before testing the LED display

The Window page for Window COMP lets you record the displayed operator, Display and window size. Check Window Operator, Display and the dimensions for the path. The Open/Close documentation recommends one large Perform Window for final content; Open as Separate Window serves auxiliary windows or tests.

V-Sync Mode Enabled updates with the monitor refresh to avoid tearing and dropped frames. Disabled allows updates at other times during the refresh and may cause those effects. FPS is Half Monitor Rate is described for ratios such as a 30 fps file on a 60 Hz display: each update appears for two refreshes. Record the actual rates; this setting alone does not verify external reference or a camera.

Hardware Frame-Lock in Window COMP is marked obsolete and points to Direct Display Out TOP. The section on direct output explains its requirements; check that path before replacing a window control.

We suggest first checking a window with the intended content and preserving its settings. Observe the physical output, not only the operator viewer. If you compare a V-Sync change, record tearing, motion continuity and the filmed result separately. No GLMedia test is claimed here.

Window COMP: monitor, window and V-Sync before testing the LED display
Path	Controls or supporting sources to check	Result to observe
GPU window	Window Operator, Display, size and V-Sync Mode; build and driver.	Physical display and motion; reference and clip separately.
Video-card output	Library, Device, Active, Signal Format; model-specific manual and driver.	Received format, output states and counters.
Quadro Sync II reference	v04 manual: Frame Lock, external reference and BNC function.	Physical state and topology; filmed content still needs checking.

Video Device Out TOP: choose the device and separate reference from groups

Under Parameters - Device Out Page, Derivative says to choose Library before Device. Active enables the card and Signal Format defines resolution, rate and progressive or interlaced transport. For interlaced formats, rates are expressed in fields per second. Preserve that notation when recording what is sent and what the receiver reports.

Reference Source is documented for AJA and offers Default, External Ref In and SDI inputs. It is a control on that video device, not a GPU or Quadro Sync II reference selector. Check the number of inputs and usable formats against the actual model.

Sync Outputs requires Pro, and the Latest documentation lists Deltacast FLEX and Blackmagic with reference connected. Sync Group Index groups nodes. For DeckLink 8K Pro, the SDK distinguishes subdevices within one card from a group spanning cards. Check that specific scope before concluding that internal synchronization proves external reference.

Output Transfer Mode offers Automatic, Default and Pinned. The text describes transfers among GPU, memory and card; it does not offer the On-Demand, Sync to Frame Input capture mode. Record the mode and path before comparing performance. Transfer selection does not replace checking signal, reference and group synchronization.

Quadro Sync II v04: external reference and states worth recording

The Working with Quadro Sync II section, printed page 7 / PDF page 11, separates Mosaic, Frame Lock and synchronization to an external source. Frame Lock aligns displays to a selected display as the timing reference; external reference aligns a selected display to a generator.

For the external connection, printed page 22 / PDF page 26 lists TTL, bi-level and tri-level over BNC and warns against connecting an external source when that port is configured as sync output. Check signal, level and port function against the manual and the actual unit before connecting. A BNC connector alone does not identify the reference protocol.

The printed page 23 / PDF page 27 distinguishes edge selection, interlaced-signal identification, Sync Interval and Sync Delay. Check edition v04 against the actual driver before publishing a configuration sequence. Record those values; select edge and frequency for the outputs and format in the setup.

On Windows, printed page 28 / PDF page 32 says to open NVIDIA Control Panel and View System Topology to check Framelock sync pulse and External sync signal. Save the unit’s displayed states and display identities. The manual’s figure is an example, not a screenshot from the setup or confirmation of its lock.

Output Info CHOP: lock, queues and delivered frames

Under Specific Video Device Out TOP Info Channels, connected reports whether the device is connected or active. genlocked uses 1 for known lock, 0 for no lock and -1 when the state is unknown. A -1 does not establish a reference failure.

Output counter names are dropped_frames and skipped_frames; do not confuse them with capture’s frames_dropped and frames_skipped. Record the operator, rates and interval along with counter changes. The manufacturer’s definitions help identify which stage to inspect; they do not by themselves identify a PCIe, driver or card fault.

frame_queue_length and frame_hw_queue_length represent frames in software and hardware queues. They are not a complete latency measurement to the LED display or camera. Record what each model reports, including unknown or unavailable values, and save readings before Reset Stats.

For a proposed comparison, record rates, states and counters at the beginning and end of the same content. Keep the format fixed and change one agreed variable outside the live show. If only one counter changes, also record what appears at the receiver and in the clip; the test has not been run.

Output Info CHOP: lock, queues and delivered frames
Output channel	Documented description	Data to preserve
connected / genlocked	Activity or connection; known lock 1, no lock 0, unknown -1.	Equipment, reference, state and evidence.
dropped_frames	The output had no new data; it may increase if the process cannot keep up with the format rate.	Rates, interval and increase.
skipped_frames	Produced frames not consumed by the output; possible PCIe or device limits.	Configuration and observation at the destination.
late_frames	Frames delivered to the card on time but displayed later; usually Blackmagic.	Model, availability and increase.
frame_queue_length / frame_hw_queue_length	Frames in software and hardware queues.	Readings for each test; measure final latency separately.

Complete the worksheet and connect input, output and camera

Use the blank TouchDesigner output and reference worksheet. Preserve the initial state, the changed variable, the result and the return to the agreed configuration. Keep Derivative or NVIDIA requirements separate from your test observations.

Connect this path with Video Device In TOP: capture, VENICE: reference and filmed display and GEN10: generated reference. For a conference with LED, recording and streaming, keep a record for each destination while planning video processing and distribution.

The actual build, driver and models, card and LED-processor manuals, and clip test remain to be checked. Further down, the direct-display worksheet helps plan that comparison.

Direct Display Out: check Windows, GPU and license

Identify the GPU, driver and connectors before choosing direct output.

Derivative documents direct output through DisplayPort/HDMI, up to three outputs, and an Educational, Commercial or Pro license; Hardware Frame-Lock requires Pro. It also specifies an NVIDIA RTX/Quadro workstation GPU and Windows 11 Pro for Workstations or Enterprise to remove outputs from the desktop. The Latest page shows a February 10, 2025 edit; the event build remains unknown.

The NVIDIA Configure DDisplay 1.8 page recommends an RTX R550 or later driver and lists Windows 11 Pro/Enterprise 21H2 or later. That list differs from Derivative’s requirement. Record the full edition and check the particular build, GPU and driver combination before changing the system; a utility’s list does not establish TouchDesigner compatibility.

Direct Display Out: check Windows, GPU and license
Check	Document reviewed	Setup data
Direct output	Educational, Commercial or Pro; Hardware Frame-Lock requires Pro.	TouchDesigner license and build.
Windows	Derivative: Pro for Workstations or Enterprise. NVIDIA DDisplay 1.8: Pro/Enterprise 21H2+.	Full edition and version; discrepancy to resolve.
GPU and driver	NVIDIA lists RTX 4000 Ada Generation; recommends RTX R550 or later for DDisplay 1.8.	Exact model, installed driver and utility.

Remove a display from the desktop and plan the return

NVIDIA explains that a removed display can no longer extend or clone the desktop; its utility can also return it. The help is available through configureDdisplay.exe --help. Save the initial setup and the return procedure for the installed version before testing.

We suggest working outside the live show with one identified output and an available control display. Record which display will be removed, its resolution, refresh rate and physical destination. If the display does not match the record, correct its identity before proceeding.

The operator uses Active, Display and Hardware Frame-Lock. Selecting Display routes the image; activating the node does not verify reference or the camera clip. Test the agreed content and record what appears at the receiver. This test has not been run.

Affinity: select the GPU when monitors change

For a proposed test, record the installed build, GPU and available gpu_bus_id before changing affinity. Then compare the GPU assignment, physical output and recovery after a monitor change. This is a test procedure, not a result from the setup.

GPU Affinity and Affinity Usage explain selection by monitor or bus. -gpuformonitor uses the Monitors DAT index, which differs from the Windows number. -gpubusid accepts domain:bus:device:function; gpu_bus_id supplies the value and affinity lets you review the assignment. IDs can vary among machines: obtain them from the actual server, not an example.

The official 2023.12230 release notes, March 4, 2025 record -gpubusid and gpu_bus_id for supported GPUs.

Monitors DAT reports detected monitors and changes in connection, resolution or primary display. It offers Units Native and DPI Scaled. Save the unit choice when comparing tables; a scaling difference does not prove an output fault.

Affinity: select the GPU when monitors change
Point in the proposed test	Record	Next step
Before changing outputs	GPU, driver, build, Windows edition, Monitors DAT table and units.	Identify monitor, bus and physical destination.
After the change	Detected monitors, gpu_bus_id and affinity if the build reports them.	If assignment differs, stop the comparison and review process startup.
During playback	Display, Active, reference, image and motion continuity.	Keep evidence for each destination; affinity data does not prove frame lock.
At the end	Return to the desktop and control access.	Confirm recovery before closing the test.

Worksheet for checking direct output

Complete the blank direct-display and affinity worksheet. Include the state before the change and the way back. Record the manufacturer’s requirement, the setting you propose to test and the observed result.

If gpu_bus_id is missing, record the version and available table. If Direct Display does not list the expected destination, use the display identity and GPU worksheet before changing Mosaic or reference. The proposed comparison has not been run.

Use the capture guide when the path also has video inputs. For a conference projection or LED display, plan each destination with video processing. The Windows discrepancy, actual hardware and drivers, remote access and recovery with event content still need checking.

Displays with the same name: identify the destination and review the saved file

The official notes for build 2023.12120, December 16, 2024 document a more descriptive Display selection and ask users to select it again in existing files. Save a copy of the .toe file before preparing that review; identify the destination from its data and check the physical output. TouchDesigner was not updated and no project file was loaded for this guide.

Identical display names alone do not establish the cause of a selection problem.

Missing display: check the process GPU and record each identity

GPU Affinity and Affinity Usage let you record the GPU associated with the process and inspect affinity. Before changing names or EDID, compare that assignment with physical connections and the intended output.

Direct Display Out TOP documents up to three outputs. We do not apply that as an automatic fix: the GPU model, driver and actual output layout are needed first. The Multi-GPU Mosaic documentation warns about duplicated work and performance. Check the cross-GPU path before choosing that option.

NVIDIA DDisplay 1.8 distinguishes removing a display from the desktop from acquiring it through another API. Save the states reported by the utility without treating them as a genlock reading. Its executable help was not consulted; the meaning and conditions of each state remain to be checked for the installed version.

We suggest making a table for the setup before changing anything. Use one row per destination and record the name each tool shows. Display Index in DDisplay, the Monitors DAT index and the operator’s Display selection are not assumed to be equivalent.

The blank display identity worksheet starts without results. Compare one destination at a time outside the live show, and record which receiver showed the content. If the identity or GPU does not match the record, resolve that before proceeding to reference or synchronization. Preserve control access and the return to the desktop.

Missing display: check the process GPU and record each identity
What to record for each destination	Where to get it	Proposed check
Port and physical receiver	Setup path: cable, matrix, LED display or projector.	Match the data with an observed output.
Name and identifiers	DDisplay table: Adapter Index, NVAPI DisplayId, OS TargetId and Display Index, if reported.	Keep the full row; a repeated name alone does not identify the port.
Process GPU	TouchDesigner startup and available affinity data.	Compare assignment with the GPU connected to the destination.
Saved selection	Operator Display, build and copy of the .toe file.	Review the selection on load; record what each screen receives.

Frequently asked questions

Do Video Device Out settings control a window sent by the GPU?

Video Device Out TOP uses output-device libraries; Window COMP controls a window on monitors. Identify the physical path before choosing settings. For a card, record Library and Device; for a window, record Window Operator, Display and size.

Does V-Sync Mode Enabled confirm genlock with the camera filming the LED display?

The Window COMP documentation describes updates synchronized with the monitor refresh to avoid tearing and dropped frames. It does not report external reference or camera lock. Save the mode, monitor rate and physical states separately, then check filmed content. That test remains pending.

What is FPS is Half Monitor Rate for in Window COMP?

Derivative describes it for ratios such as a 30 fps file on a 60 Hz display: each update appears for two refreshes. Check actual rates before comparing it.

What conditions does TouchDesigner specify for Sync Outputs?

Video Device Out TOP requires Pro for Sync Outputs and lists Deltacast FLEX and Blackmagic. Sync Group Index identifies the group. The general documentation calls for reference; for DeckLink 8K Pro, the SDK permits internal synchronization without a common reference but requires it between devices. Check model, build and driver against the specific guide before grouping cards.

Does Video Device Out Reference Source select the Quadro Sync II reference?

That setting is documented for AJA devices. Quadro Sync II has its own configuration and physical reference under the v04 manual. Record the paths separately. NVIDIA warns against connecting an external source to a BNC configured as sync output; verify port function and signal before connecting the unit.

Does genlocked = -1 mean the card lost reference?

It means the state is unknown, according to the output Info CHOP. The channel uses 1 for known lock and 0 for no lock. Save the model, driver and available data, then compare them with the equipment’s signal and state. Do not treat unknown data as a confirmed fault.

Do dropped_frames and skipped_frames indicate the same output problem?

dropped_frames counts times when the output had no new data; skipped_frames counts produced frames not consumed by the output. Compare rates and increases over a recorded interval, with late_frames and available queues. These are output data; capture counters use different names and describe other stages. Neither final latency nor a hardware cause was measured here.

Does a custom resolution on a P5000 always require Sync II?

Resolution alone does not determine that requirement. The Sync II v04 manual distinguishes Mosaic, Frame Lock and external reference. Identify the GPU, driver and path, then use that scope to plan a test.

Is Windows 11 Pro sufficient for Direct Display Out TOP?

Derivative specifies Pro for Workstations or Enterprise; NVIDIA DDisplay 1.8 lists Pro/Enterprise 21H2+. Record edition, build, GPU and driver, and resolve the difference for that combination before changing Windows.

Does a Commercial license enable Hardware Frame-Lock in Direct Display Out?

The operator supports Educational, Commercial and Pro, but Hardware Frame-Lock requires Pro according to Derivative. Check both conditions separately along with the physical reference. Neither license nor lock was tested for the setup.

Why might -gpuformonitor stop selecting the GPU after displays are removed?

It selects by a detected monitor. The documentation allows selection by bus and checking affinity; save actual IDs and build before planning a different process startup.

Can I copy the example GPU ID for -gpubusid?

Get the server’s value from gpu_bus_id and preserve the table. Derivative warns that IDs can differ among machines. Check affinity after startup; correct assignment still does not verify the destination image or synchronization.

What should I save before removing a display from the desktop?

Identity, resolution, refresh rate, destination and control access. NVIDIA documents that the display stops extending or cloning the desktop and can be returned. Consult the installed utility’s help and record the return procedure before an off-show test.

Do Monitors DAT units affect resolution comparisons?

Units distinguishes Native from DPI Scaled. Save the selection with each table and compare equivalent data. The table reports detected monitors; it does not certify the signal received by an LED display or projector. Record that observation separately.

Do two displays named HDMI Matrix prove that EDID caused the failure?

OS TargetId helps distinguish displays in the build 12120 documentation. That does not confirm an EDID fix. Save identities and the actual model before changing the matrix.

What should I check if Direct Display does not show a screen connected to another GPU?

Compare the process GPU with the GPU connected to that display. Also record build, driver, destination state and number of outputs. That was not verified as the problem on the setup described. Review the assignment in the affinity documentation and compare it with actual connections.

Should I review Display when opening a .toe file after changing versions?

The build 2023.12120 notes ask users to select Display again in existing files. Work on a copy, record the destination and check the received image. This applies to that documented change; it is not a completed test or an instruction to update every setup.

Can the DDisplay index be used directly as a Monitors DAT index?

We have not established equivalence among those lists and the Display menu. Record each index with its tool name and relate every row to the GPU and physical receiver. If values differ, preserve both records and review the selection; do not change an index merely because its number matches.