How Many GPU Can A Motherboard Support? — [Explained]

There was a time when motherboards used to accommodate only one graphics card to perform all those graphics-intensive tasks. And now, you see motherboards like Asus H370 Mining Master that simultaneously accommodate up to 20 graphics cards. Isn’t it crazy?

However, you know that crypto mining is different from gaming and content creation. So, how many GPUs does a typical motherboard support? Most of the current-era motherboards can accommodate up to 2-4 graphics cards at a time; a few may support up to 6 GPUs. 

That said, you should also know what are the exact factors that influence the number of GPUs a motherboard can support. You should also be aware of how many cards your motherboard can accommodate. So, keep reading this detailed guide to discover this!

How Many GPUs Can A Motherboard Support?

The exact number of graphics cards (also known as GPUs) depends on the design and size of the motherboard. While most motherboards accommodate 2 to 3 graphics cards, a few can support up to 4 or even 4+ GPUs, depending on their usage purpose. 

2-3 Graphic Cards — Aimed at consumers, gamers, and casual users, motherboards with these GPU configurations are made for tasks like light video editing, 3D rendering, and some gaming at higher resolutions or with demanding textures.

4 Graphic Cards — Found on high-end gaming and enthusiast motherboards designed for pushing performance limits this configuration is for intensive tasks like hardcore gaming, professional video editing, or scientific computing.

More than 4 Graphics Cards —  Rarely seen in consumer-grade motherboards but common in specialized equipment like workstations and cryptocurrency mining rigs. Offers maximum GPU expandability for extremely demanding tasks.

Factors Affecting Number Of GPUs A Motherboard Can Support

The following are some factors that affect the number of GPUs that a motherboard can support:

The Number Of PCIe Slots

The number of PCIe (Peripheral Component Interconnect Express) slots on a motherboard determines the maximum number of GPUs that can be installed. Most motherboards have 4 PCIe slots, but some have more.

The Type Of PCIe Slots

The type of PCIe slots on a motherboard also affects the number of GPUs that can be installed. Some motherboards have PCIe x16 slots, the fastest type of PCIe slots, followed by x8, x4, and x1, gradually becoming slower. 

Some motherboards may have multiple PCIe x16 slots, but not all of them may operate at the full x16 speed when populated simultaneously. For example, a motherboard may support two GPUs with x16/x8 lane configuration.

The PCIe Bandwidth

The PCIe bandwidth determines how much data can be transferred between the GPU and the motherboard. Although most motherboards have enough PCIe bandwidth to support 4 GPUs, simultaneously, some may not.

Methods Of Implementing A Multiple GPU Configuration

A Multiple GU Configuration, also known as multi-GPU configuration or multi-GPU setup, is an arrangement to use two or more graphics cards together. In this setup, both GPUs work parallelly to process graphics calculations and perform graphics-related tasks. 

These are a few methods to implement a multiple GPU configuration:

NVIDIA SLI (Scalable Link Interface)

Description: NVIDIA develops this technology to combine two or more NVIDIA GeForce graphics cards in a compatible motherboard.

How it Works: SLI allows the GPUs to collaborate as a unified processing unit, splitting the graphics workload and improving performance in applications that support SLI.

Compatibility: Requires a motherboard with compatible SLI support.

NVLink (NVIDIA GPUs)

Description: NVLink is a high-speed interconnect technology used in professional-grade, high-quality NVIDIA GPUs.

How it Works: NVLink facilitates faster data transfer and communication between linked GPUs. It is ideal for high-performance scientific simulations and computing.

Compatibility: Primarily used in professional-grade GPUs and data center environments.

AMD CrossFire

Description: Developed by AMD, CrossFire is a counterpart to NVIDIA’s SLI. It enables users to link two or more AMD Radeon graphics cards in a CrossFire configuration.

How it Works: Similar to SLI, CrossFire allows linked GPUs to work together, enhancing graphics performance in applications that support CrossFire.

Compatibility: Requires a motherboard with compatible CrossFire support.

DirectX 12 Multi-GPU

Description: DirectX 12 is a graphics API developed by Microsoft. It introduces native support for multi-GPU configurations without relying on CrossFire or SLI profiles.

How it Works: Applications and games can potentially benefit from multiple GPUs without needing particular driver support from GPU manufacturers.

Compatibility: Requires applications and games that support DirectX 12 multi-GPU functionality.

Do My Motherboard Support Multiple Graphics Cards?

To know whether your motherboard supports multiple graphics cards, first, open its user manual or go through its specifications online. Check the following factors:

There Must Be Enough PCIe Slots. Look for the number of PCIe slots on your motherboard either by physically inspecting it or by looking at its specifications chart. 

PCIe slots come in different sizes (x16, x8, x4), and the primary slots for graphics cards are typically PCIe x16 slots, although a GPU can work with x8 or x4 slots as well. Ensure there are enough PCIe slots to accommodate the number of GPUS you want to install.

Confirm That The GPU Technologies Match. 

As we have told you earlier, there are different methods to implement multi-GPU configuration. However, to use multiple cards on a motherboard, all the cards should be using the same configuration, such as AMD Crossfire and Nvidia SLI. 

So, first, see what configuration your motherboard supports. Once you are clear with it, get the graphics card with the same Multiple GU Configuration for proper synchronization.

Why Use Multiple Graphics Cards In One System?

As obvious, increasing the graphics processing power is the main reason most people consider multi-GPU. By splitting the rendering workload between multiple cards, you can achieve:

• Higher frame rates: Perfect for pushing visual fidelity in demanding games or running at higher resolutions like 4K or 8K.
• Smoother performance: Reduces frame drops and stuttering in graphically intensive applications.
• Faster processing: Benefits non-gaming tasks like 3D rendering, video editing, and complex scientific simulations.

In addition to increased graphics performance, another reason is redundancy. If one GPU fails, you can typically still function on the remaining card, though performance will be reduced.

Some Tips When Installing Multiple Graphics Cards

Use a power supply that can handle the power requirements of all the graphics cards along with the other components. As obvious, multiple GPUs draw a lot of power. Your previous power supply may not be enough to work with your new multi-GPU setup.

When installing another graphics card, DO NOT forget to check the total power consumption of all the GPUs and other components such as memory, CPU, cooling system, storage, etc. Pair a suitable power supply unit (PSU) with sufficient wattage (more than you calculated).

Install the GPUs in the correct slots. The PCIe slots on a motherboard are numbered. Look at all the PCIe slots and install the GPUs in the slots that are closest to the CPU with the highest pin configuration. Pin configurations include x16, x8, x4, x1 (fastest to lowest).

Update the BIOS. The BIOS is the software that controls the motherboard. You may need to update the BIOS to support multiple GPUs.

Conclusion:

The number of GPUs a motherboard can support depends on factors like PCIe slots, their types, and bandwidth. Consumer-grade boards typically handle 2-4 GPUs for tasks like gaming, while high-end models support up to 4 for intensive activities. 

Rarely seen on consumer boards, more than 4 GPUs are common in specialized equipment like mining rigs. That said, check the PCIe slots present on your motherboard, their types, and bandwidth, as these factors influence a motherboard’s GPU support.

Sajid Ali