External graphics system and external graphics method

An external graphics method utilizing an external graphics system to enhance graphics performance, the external graphics system including a host device at least having a first graphics processing unit and a central processing unit, and an external graphics device connected to the host device, the external graphics device at least including a second graphics processing unit and a Thunderbolt (TBT) interface unit;

• the central processing unit being used to issue a first request command to instruct the first graphics processing unit to perform a graphics processing, and/or a second request command to instruct the second graphics processing unit to perform the graphics processing;
• the external graphics method including:
• the central processing unit determining whether the graphics processing of the second graphics processing unit exceeding a load-carrying capacity threshold based on the second request command;
• when the graphics processing of the second graphics processing unit not exceeding the load-carrying capacity threshold, the second graphics processing unit receiving the second request command through the TBT interface unit and performing the graphics processing accordingly to generate a second video stream signal, and converting the second video stream signal into a TBT signal, transmitting the TBT signal to the host device through the TBT interface unit, and the host device displaying an image frame corresponding to the TBT signal;
• and
• when the graphics processing of the second graphics processing unit exceeding the load-carrying capacity threshold, the central processing unit redistributing the second request command and the first request command, the first graphics processing unit receiving the allocated first request command and performing the graphics processing accordingly to generate a first video stream signal;
• the second graphics processing unit receiving the allocated second request command through the TBT interface unit and performing the graphics processing accordingly to generate the TBT signal corresponding to the second video stream signal, the central processing unit integrating the TBT signal and the first video stream signal to obtain a third video stream signal, and the host device displaying an image frame corresponding to the third video stream signal;
• wherein when the graphics processing of the second graphics processing unit exceeds the load-carrying capacity threshold, the central processing unit redistributes the first request command based on a video traffic exceeding the load-carrying capacity threshold;
• the first video stream signal integrated with the third video stream signal is formed by the first graphics processing unit performing the graphics processing according to the video traffic indicated by the first request command.