What does Not Optimum Mode mean?

Last modified : May 14. 2018
QLED Gaming Monitors

When the Not Optimum Mode message pops up on your Samsung monitor it means that the signal from the graphic card exceeds the maximum resolution or frequency your monitor can support.

Below are some recommended guidelines to try: 

Please note: Check screen resolution is set to the Optimum Resolution as recommended or higher.

Examples below:

What does 'Not Optimum Mode' mean?

Monitor Size

Optimum Resolution

15 to 16 inches

1024 x 768

17 to 19 inches

1280 x 1024

20 to 23 inches

1600 x 1200

●     Check in Monitor Settings that the Monitor refresh rate is set to 60 Hertz, making sure that the screen resolution is set to what is recommended by PC.


●     Check that the graphic card driver is updated, (please check the manufacturer of graphic driver)

Quick Guide to Access Screen Resolution For Windows 7

Please note: For other versions of Windows operating system, the interface may slightly differ, however, the steps below may still be the same.

1 Click on the Start button on your PC then click on Control Panel. On the top right hand side, select view by Category then click on Appearance and Personalization.
What does 'Not Optimum Mode' mean?
2 Click Adjust screen resolution.
What does 'Not Optimum Mode' mean?
3 Click on the drop down next to Resolution and select the option with recommended.
What does 'Not Optimum Mode' mean?

Please note: For advance troubleshooting steps, please download the User Manual from Manuals and Software Downloads to see a list of all compatible screen resolutions for your monitor and then select your model type.

If your monitor displays the Not Optimum Mode error message after a brief inactivity or just after sleep mode then consider replacing your HDMI cable to a DVI cable. This issue is due to the computer and the monitor don't communicate with each other with the correct ACPI settings over the HDMI cable. If you still like to use your HDMI cable then you may have to modify settings on your graphics card, please refer your CPU user manual (graphic card in particular) for more details.


For further assistance, please contact Samsung Customer Care using one of the options below.

Did not find what you're looking for? We're here to help.


Chat with us

Live Chat Support with a Samsung product expert.

Mobile Support Self Service Booking

Book a Mobile Product Service Request via Australia Post

We'll respond within 24 hours of your request.

Email Escalation

We endeavour to respond within 24 hours.


1300 425 299

For all Mobile device enquiries
24 hours / 7 days a week

1300 362 603

For all other product enquiries
24 hours / 7 days a week

+612 8293 5712

From overseas
24 hours / 7 days a week

For all Printer related inquiries,
please click here
or visit https://www.hp.com/support/samsung

Please click here
to view the latest news regarding the Samsung sale of Printer business to HP.

Face-to-Face Support

Find a Service Centre

Search for the nearest Samsung Service Centre's in your area.

In-Store Support

Create a booking to see one of our friendly Samsung staff members at one of our Samsung Retail Stores.

Contact Us