Slow Real-Time Rendering
Slow Output Rendering

Slow Real-Time Rendering

KeyShot is 100% CPU-powered and it will use 100% of your CPU's processing power. The more processor cores, the faster the render engine.

How to Improve Real-Time Rendering Speed:

1. Ensure that KeyShot is using all CPU cores available.
Go to to the top ribbon menu and at the top-right corner, you will find the CPU Usage drop-down. Set it to "All Cores".

2. Go into Performance Mode.
Performance Mode turns off certain scene lighting settings (e.g. ground shadows, global illumination, etc) to improve real-time res-up/frame rate. You may use the Alt+P to toggle performance mode on/off.

3. Enable Fast Real-time Updates.(KeyShot 7 and older only)
Go to Edit (PC) or KeyShot (Mac) -> Preferences -> Advanced. Click Save Changes to save your changes in Preferences.

4. Set Disable outline for large models to "Auto".
Go to Preferences -> Interface. Click "Save Changes". This will turn off the orange outlines around models if the model is very large (in number of triangles/polys).

5. Disable Import NURBS Data when importing your CAD data.
Click Import, browse to your model and Open. Go to Geometry inside the Import window and disable Import NURBS Data.

6. Work on a few parts at a time.
Hiding parts and showing only the ones you are currently working on helps improve performance.

7. Decrease your real-time view's resolution.
You may set the real-time resolution from within the Project window's Image tab. You may also drag a corner on the real-time window.

If you are still experiencing slow real-time rendering, please contact us at
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Slow Output Rendering

KeyShot is 100% CPU-powered and it will use 100% of your CPU’s processing power. If you double the number of cores, you potentially cut your render time in half.

Besides CPU cores, the only other thing that affects KeyShot’s output performance is the image quality. Image quality, in turn, depends on the image’s resolution and the output settings used to render the image.

How to Improve Output Performance:

1. Reduce your output resolution.
To change your output resolution go to Render -> Render -> Output.

2. Use the Basic preset for real-time lighting.
In KeyShot 6 and later, you may find this lighting preset under Project -> Lighting. This preset provides simple, direct lighting with shadows, which is best for basic scenes and fast performance. Use basic lighting when rendering simple models illuminated by the environment.

For more information about the real-time lighting settings, click here.

3. Use a different render quality setting: Maximum Samples, Maximum Time, or Advanced Control

Maximum Samples
This render method uses the same algorithm as the real-time window. To find the right number of samples, you can perform the following steps:

1. Open your scene and press the H key to reveal the heads-up display (HUD).
2. Go to Project  > Image tab and enable Region (Pro only).
3. Adjust the region marquee to focus on a small area on your model. 
4. Let your image res up without disturbing the realtime window.
5. Once your region looks as desired, make a note of the Samples count in the HUD.

Use the HUD setting in your final output (for Maximum Samples only). If your version of KeyShot does not include Region rendering, you may instead zoom into an area of your model and reduce your real-time resolution.

Quick Tip: Using Region Rendering

Quick Tip: Output Render Samples

Maximum Time
You can always render with Maximum Time.  Maximum Time will provide you with the best possible image in the amount of time that you specify.  The beauty of using Maximum Time is that you can always click Stop and Save (the image) before time is up if all looks as expected.

Advanced Control
This is a custom render mode that allows you to control all quality settings. Advanced Control will sometimes resolve grainy materials at a lower Sample count. Use Advanced Control if Maximum Samples is not giving you the desired results after 1000 samples.

For best result, you may leave all settings at their default values and just modify the Samples count. Settings like Shadow and Ray Bounces are only relevant in certain situations. For more information about the advanced control render settings click here.

How to find the right number of Samples:

1. The rule of thumb is to start with 32 Samples.
2. Render a test image at lower resolution (say, 800x800).
3. If your low-resolution image looks good, then you can render at the desired resolution with 32 Samples.
4. Otherwise, double the number of samples (64 Samples) and test again.

Repeat this process until you achieve the desired output.

4. Increase your CPU power with KeyShot Network Rendering.
For more information about KeyShot Network Rendering, please go to our product page or consult the Network Rendering Manual.  You may also contact our sales department at

5. Third Party Render Farms.
If you are unable to modify your scene or your hardware setup, you have the option to send your scene to a third party for rendering. Companies such as 3D Off the Page and RevUp Render have their own KeyShot Network Rendering farm and offer such services.

6. Disable App Nap (Mac OS only)
When rendering on Mac OS X and the screen turns off or if KeyShot isn't the active app, the operating system slows down the CPU usage of the rendering.This makes the render times unnecessary long.

*Note* Turning this off my impact every task, process, or application that runs in the background of OS X.

  1. Open the Terminal app, found in /Applications/Utilities/ folder
  2. Copy and paste the following defaults string into the Terminal, then hit the return key:
      write NSGlobalDomain NSAppSleepDisabled -bool YES
  3. Close out of Terminal and restart the Mac for the changes to carry through

Like other default command strings, there is no confirmation. Once the Mac has been restarted, you can confirm that App Nap is not working backgrounding a couple of the processes or hiding inactive applications for 30 minutes or so, then check the "Energy" panel in Activity Monitor. Look under the "App Nap" sort section and everything will be listed as "No" including the app that was backgrounded.

If you are still experiencing slow performance, please contact us at