If PCs have a dedicated graphics card with video connectivity ports then why do motherboards have HDMI ports as well? Why have the redundancy?
The answer to this question is fairly simple. Motherboards have HDMI ports for connecting your monitor to IN CASE if your PC does not have a dedicated graphics card.
Many budget and non-gaming PCs out there lack a dedicated graphics card hence the only method of connecting your monitor display to your PC is through the motherboard HDMI port (or other video output ports including VGA, DVI, DP etc.).
In the following text I will talk in the detail about why motherboards have HDMI ports in detail and also talk about some very important caveats.
So Why Do Motherboards Have HDMI Ports?
A majority of the motherboards out there offer video output ports. These are intended for basic video connectivity for your monitor to your PC.
It should be noted that motherboards may not just offer HDMI ports, they can offer a combination of video output ports including HDMI, VGA, DVI, DP etc.
Additionally while all ports carry video signals, only the HDMI or the DP port carry the audio signals too.
Now in order for the motherboard HDMI port, or any video output port on the motherboard to work, you NEED to have a CPU with an integrated graphics card. Let me explain this further:
Motherboard HDMI Port is Powered by the iGPU
Motherboards do not have an onboard graphics processing chip. In other words, they rely on the CPU’s integrated graphics card in order to power their video output ports.
If your CPU lacks an integrated graphics card, then the motherboard video output ports, including the HDMI port will simply not work.
In that case, you will absolutely have to have a dedicated graphics card for connecting your display to.
Intel F series CPUs such as the Intel Core i7 12700F, Intel Core i5 12600KF all LACK an integrated graphics card.
With AMD, only the G series CPUs such as the AMD Ryzen 7 5700G HAVE an integrated graphics card.
As such, while motherboards do have an HDMI port, in order for them to work, you have to make sure that your PC has a CPU with an integrated graphics card.
Also Read: Intel K vs KF vs F Series CPUs
Do You Need a Dedicated Graphics Card If You Have HDMI Port on Motherboard?
That depends entirely on what you intend to do with your PC.
If your PC is intended for graphics intensive tasks such as gaming or rendering 3D graphics, then you will certainly benefit from having a dedicated graphics card.
If your PC is intended for simple day to day work or office work, then you do not need to have a dedicated graphics card. You can simply use the HDMI port on the motherboard for connecting your monitor to (again granted that you have a CPU with an integrated graphics card).
Which HDMI Port to Use If You Have Motherboard HDMI and GPU HDMI?
Another common question is which HDMI port to use if you have both the motherboard HDMI port as well as an HDMI port on your dedicated graphics card?
In this arrangement, you should use the the HDMI port on the DEDICATED GRAPHICS CARD.
This is because dedicated graphics card are much more powerful as compared to the integrated graphics card found on the CPUs.
Since motherboard HDMI port uses the much weaker iGPU for rendering instead of the dedicated GPU, you will have a far worse performance as compared to connecting your monitor to the HDMI port on the dedicated GPU.
TL;DR just use the HDMI port on the dedicated graphics card.
Can You Use Both the Motherboard and the Dedicated GPU HDMI Ports?
If you have multiple monitors then you may wish to utilize the HDMI port on both the motherboard as well as on the dedicated graphics card.
However, in majority of the cases, when you install a dedicated graphics card onto the motherboard, the integrated graphics card gets disabled. As a result, the HDMI ports on the motherboard also get disabled.
Fortunately, though, there is a way for some PCs to circumvent this issue through BIOS. However, whether this feature is available to you or not depends upon your BIOS version and how comprehensive it is.
In order to enable the motherboard HDMI port you will need to:
- Access BIOS
- Search for options regarding iGPU
- Enable the iGPU
- Save the BIOS Settings
- Reset Your PC.
I have written a comprehensive guide on this topic: How to Use Motherboard HDMI with Graphics Card?
Again a minimal BIOS, such as the one shown below, will not feature any option to enable the iGPU.
There is one very critical caveat to using the motherboard HDMI port along with the HDMI port on the dedicated GPU:
The Monitor Connected to the Motherboard HDMI Port will Have Horrible Performance
If you can successfully use the motherboard HDMI port along with the HDMI port on your dedicated GPU, you must note that the monitor connected to the motherboard’s HDMI port will have horrible performance in comparison.
This is because, as explained earlier, the motherboard’s HDMI port uses the much weaker iGPU for rendering. The HDMI port on the dedicated GPU uses the much more powerful graphics processing chip.
Hence, while you will have a multiple monitor display, you will notice that the monitor connected to the motherboard will have severe frame drops while the one connected to the dedicated GPU will be smoother PARTICULARLY when gaming.
So why do motherboard have HDMI ports? Well TL;DR, for connecting your monitor to in case if you lack a dedicated graphics card.
Budget and non-gaming PC’s often lack a dedicated graphics card. Hence, the motherboard HDMI port in such cases can be used for connecting your monitor to.