This article applies to:
E-Prime 3.0
E-Prime 2.0
E-Prime 1.x
NOTE: This issue has only been replicated using G-Sync at this time. Please share any FreeSync issues and results with PST Support or comment below so that we may update this article accordingly.
NOTE: Please see To know if G-SYNC is enabled for your game (nvidia.com) and How to Enable AMD FreeSync™ | AMD if you are not sure if you are using G-Sync or FreeSync. For AMD, check for the presence of "Radeon FreeSync" and if it's Enabled.
Symptoms
Freezing or an "Unable to obtain a valid refresh rate" error occurs when running an experiment with G-Sync or FreeSync enabled.
Detail
E-Prime uses the vertical blank for timing of when E-Objects appear on-screen. This allows consistent refresh rates and accurate timing to be achieved.
E-Prime relies on fixed refresh rates and does not detect when the vertical blank changes. The use of variable refresh rates allows E-Objects to display inconsistently which negatively impacts timing.
Solution
The following solutions are possible:
Solution 1
Disable G-Sync and FreeSync on your monitor and/or in its graphic settings.
NVIDIA:
- Open NVIDIA Control Panel.
- Select "Set Up G-SYNC".
- Uncheck the box "Enable G-SYNC".
AMD:
- Open AMD Radeon Software.
- Select the "Display" tab.
- Uncheck the box "AMD FreeSync".
NOTE: This can also be disabled physically on the monitor. For more information on how to disable G-Sync and FreeSync on the monitor or in software, consult with the hardware manufacturer.
Solution 2
In the graphics settings set the E-Studio and E-Run program to use a "Fixed Refresh".
NVIDIA:
- Open NVIDIA Control Panel.
- Select "Manage 3D Settings".
- Select "Program Settings" tab.
- Click "Add" button.
- Browse and select the application (e.g., E-Studio and E-Run) or use the entire E-Prime folder.
- Locate Monitor Technology and set it to "Fixed Refresh Rate".
AMD:
- Open AMD Radeon Software.
- Select the "Gaming" tab.
- Click "Add" button.
- Browse and select the application (e.g., E-Studio and E-Run).
- Select the added application.
- Locate AMD FreeSync and set it to "Off".
For more information, consult with the hardware manufacturer.
See Also:
RELEASE INFO: Known Issues in E-Prime 3.0 [27789]
RELEASE INFO: Known issues in E-Prime 2.0 [19406]
ERROR: AMD or NVIDIA overlay appearing on screen when running experiments [34405]
Comments
2 comments
Freezing or an "Unable to obtain a valid refresh rate" error occurs when running an experiment with G-Sync or FreeSync enabled. E-Prime uses the vertical blank for timing of when E-Objects appear on-screen. This allows consistent refresh rates and accurate timing to be achieved.If you want low human benchmark input lag and don't mind tearing, then the FreeSync standard is a good fit for you. On the other hand, if you're looking for smooth motions without tearing, and are okay with minor input lag, then G-Sync equipped monitors are a better choice.
Thanks for the detailed explanation – it makes a lot of sense that E-Prime’s v-blank based timing falls apart when VRR is enabled.
We ran into very similar freezes on 144 Hz G-Sync displays and only got stable timing again after forcing a fixed refresh rate for the E-Prime executables.
For people who want a quick way to see how different monitor settings affect latency and frame pacing, simple browser tests like reaction time or sequence memory can be useful. One example is:human benchmark You can compare results with VRR on vs. off and immediately notice how much more consistent a fixed-refresh setup is.
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