board 4 since the hdmi port 32 needs to transmit a large amount of video data the signal transmission frequency thereof is usually high in addition to the demand for better image quality the amount of data transfer for each video standard has gone up in recent years which leads to a higher signal transmission frequency of the hdmi port 32 therefore compared to the expansion port 33 the hdmi port 32 may be disposed to a position closer to the circuit board 4 i e under the integrated connecting port module 3 and the expansion port 33 with a lower transmission frequency is disposed to a position over the hdmi port 32 in the embodiment because the transmission frequency of the hdmi is in ghz the hdmi port 32 is disposed to a position closer to the circuit board 4 the expansion port 33 with a lower transmission frequency may be disposed over the hdmi port 32 for example the expansion port 33 can be a conventional vga port as shown in fig2 the expansion port 33 disposed over the hdmi port 32 can also be any of other standards such as d sub terminal ieee 1394 ieee 802 x sata ps2 and 3 5 mm stereo jack besides the 3 5 mm stereo jack 41 and usb port 42 are not the limited standards and other standards.