Wondering if it’s possible to run two monitors on two separate GPU’s and how to do it? We can help!
A single graphics card or even a powerful CPU is usually enough to run two monitors at once, but not always. Maybe you want to play a game while your project 3D models renders, or maybe you want to play two games at once (you maniac), or maybe you want to work on two GPU-intensive projects at once.
Or heck, maybe you just have a spare GPU laying around and you want to put it to use.
This quick guide will cover the possibilities, pros, cons, and everything else you need to know about running two displays on two graphics cards.
Is it Possible?
The good news is that it’s technically possible to run two monitors off of two GPU’s. The bad news is that it’s going to take some work, and there’s no real guarantee you’ll get the results you want—especially if you’re using Windows 10.
Ironically it would have been more feasible in previous years; Windows XP supported multi-GPU setups, and both AMD’s Crossfire and NVIDIA’s SLI made it relatively easy to link two GPUs together, but things have backslid a bit since then.
Windows 10 lacks the multi-GPU features XP had, AMD stopped supporting Crossfire, and NVIDIA’s SLI quietly died. Granted, NVIDIA did replace SLI with NVLink—a significant improvement in terms of performance—but only a small handful of GPUs are NVLink-capable.
That being said, it may be possible for you to use two GPUs to run two different monitors. It probably won’t be easy, it might not work, and it’ll require some finagling, but you might be able to pull it off.
Before you skip to the instructions, though, ask yourself another question: Is it worth it?
Related: We also recently created a guide on how to run two different monitors with two different refresh rates.
Is It Worth It?
Attempting to run two monitors on two separate GPU’s is usually not worth it. Almost every online resource will recommend running one powerful GPU instead of two weaker ones, and very few users have had much success in getting a system with two unlinked GPUs to do what they want.
Pros:
- Split load between two GPU’s instead of one
- Lets you use one GPU for something important while using the other GPU for something less important
Cons:
- Can require a lot of troubleshooting
- Windows Desktop Window Manager gets confused by two-GPU, two-monitor setups
- May require weird workarounds
- Extra heat from second GPU can overwhelm computer’s cooling system
- Extra power draw from second GPU can overwhelm power supply
- Motherboard may not support second GPU
- CPU may not be able to handle two GPU’s
Your specific setup (and your luck) might be a big factor in your success. Your CPU might not be able to handle the increased load, it might not be able to accurately direct both GPUs at once. Windows 10’s Desktop Window Manager usually doesn’t take kindly to systems with two GPUs that want to work independently.
There are only a few edge cases where this is even feasible, let alone practical. It would be a fun experiment if you already have two GPUs on hand, for instance.
Or it could be nice to play a game without taking up resources that your CAD or design software needs to render an important project.
Or…actually, that’s about it. You’d be better served by getting one sufficiently powerful GPU in almost every other situation.
How-To Run Two Monitors on Two GPU’s
There’s no one method that will guarantee success if you’re trying to set up a two-GPU, two-monitor system. In fact, you might find that none of the methods work for you.
But if you’ve made it this far you probably won’t be deterred, so give these methods a shot.
Method 1: Plug, Play, and Pray
Before you try anything crazy, go ahead and plug your monitors into your GPUs and see what happens. It probably won’t work, but it’s worth a shot.
And who knows? Maybe you’ll get lucky and your computer will automatically devote your GPUs’ processing power based on what’s running on which monitor.
Method 2: NVIDIA Control Panel
Note: This method only works if you have Nvidia GPUs. The Nvidia Control Panel should be installed automatically when you install an Nvidia GPU, but you can also download it here. Also note that you have to do this for each application you want to use.
How to Use Nvidia Control Panel to Run Two Displays on Two GPU’s:
- Open NVIDIA Control Panel
- Click “Manage 3D Settings”
- Click “Program Settings”
- Click “Add” button
- Select an application
- Choose the preferred graphics processor from the dropdown
- Repeat for other applications until satisfied
This method should let you decide which GPU will handle which applications, and thus work separately on separate monitors. Some users report that they have more success with this setup if they play games in Fullscreen, not Fullscreen-Windowed thanks to a weird quirk with Windows Desktop Window Manager.
Experiment with this to see if you can get it working and move to the next method if your computer doesn’t want to play along.
Method 3: Multiseat
What do you do if you can’t get one computer to run two GPUs separately? Add another computer, of course! But wait- what if you don’t want to add another computer?
Multiseating may be your best bet.
Multiseating is a strange little process that turns one computer into multiple workstations. It’ll let you assign computer devices to specific workstations—like, say, monitors and GPUs—so it may be just what you’re looking for. It’s a weird workaround, but it may be the only way to solve the one computer, two GPUs problem.
There are a few downsides to multiseating, of course. The first is that you’ll probably have to pay for a program that enables multiseating, and there aren’t many options on the market. In fact, ASTER Multiseat may be your only option outside of experimental github projects.
It also costs around $60 for a lifetime license (though there is a free trial available), which may be more than you want to spend.
Since ASTER may be the only viable software for this precise thing, the following instructions are specific to that program.
Finally, ASTER isn’t the most user-friendly program, so you’ll want to peruse the readme and the FAQ on their website if you get confused while following this guide.
How to Use ASTER Multiseat to Run Two Displays on Two GPU’s:
- Plug your monitors into your GPUs
- Open your display settings, then set the monitors to “Extend these displays”
- Download ASTER Multiseat (do the free trial first)
- Navigate to the “Work Places” tab
- Add a workplace
- Click on the “Spare Parts” button to open the menu
- Click and drag the monitors from the menu to their respective workstations
- Do the same for mice, keyboards, and speakers
- Open the context menu and click “Customize the Workplaces panel”
- Check the “Inventory” box
- Close context menu and open Inventory menu
- Drag GPUs and other devices from the Inventory menu to their respective workstations
- Navigate to “General Settings” tab
- Make sure your workstations are enabled
- Open “How to start workplaces” menu and choose “When a system starts up”
- Click “Enable ASTER and reboot PC”
- Troubleshoot if necessary
You may need to fiddle with the settings and the devices assigned to your workstations, but this should work. ASTER even has a section in their instructions about assigning GPUs to individual workstations, so they’ve clearly thought about (practically) this exact problem.
Multiseat may not be an ideal solution, but it is a solution.
Final Recommendations
While it’s technically possible to run a two-monitor, two-GPU system, it probably isn’t worth it unless you’re willing to make the switch to Linux and/or spend some serious time and money setting up and running virtual machines.
You might see some success by just plugging your GPUs into separate monitors and seeing what happens, assigning GPU’s to specific applications in the NVIDIA control panel, or using ASTER Multiseat, but there’s no way to guarantee you’ll get the results you want.
Newer versions of Windows make it significantly harder to configure such a system than in the past, and Windows Desktop Window Manager’s strange problem with two-GPU setups can derail even the best laid plans.
If you don’t want to bother with the methods in this guide, it’d probably be a good idea to just put together another computer using your spare GPU, though that would also depend on your needs.
A cheapo setup using your spare GPU would be fine for watching movies and playing some games, but it probably wouldn’t work if you’re looking to render big projects while you game.
Whatever you decide to do, make sure you do some more research before spending any money.
Oh, and good luck!
