How-To Geek writer Sydney Butler describes a Ryzen 7 7700 and GeForce RTX 4070 Super desktop. He got it in a local trade for a workstation laptop. The desktop's budget AM5 motherboard has a VGA port, which is rare now. That port is wired to the Radeon integrated graphics in the CPU. He uses a Sun Microsystems CRT for retro and DOS gaming, so the VGA port let him drop a mini-DisplayPort-to-VGA adapter. The 4K mini-LED TV connects to the RTX card over HDMI.
This is one person's experience on one hardware combination. It isn't a compatibility guarantee. Even so, it shows a useful split between which GPU drives a display and which GPU renders the game.
The setup, step by step
Butler's account boils down to a short procedure:
- Confirm the CPU has integrated graphics. The Ryzen 7 7700 does. Many AM5 desktop chips do, but check your exact model.
- Confirm the motherboard actually exposes video outputs. Not every board does. A board with a VGA port is unusual, as Butler himself notes.
- Enable the iGPU in UEFI. Butler says he made sure the iGPU was toggled on. The menu name and path depend on the board. He doesn't name his model, so there is no universal path.
- Optionally trim the reserved graphics memory. He cut the iGPU's reserved VRAM, which comes out of system RAM, to 512MB. The rest of the machine's 32GB stays available to Windows.
- Plug each display into the right output. The CRT goes to the motherboard's VGA port. The TV goes to the discrete card's HDMI port.
- Let Windows treat it like any multi-monitor PC. He says it handled the pair the same as two monitors on one GPU.
Switching displays with Win + P
Butler uses the Windows key + P shortcut to choose which screens are active. Microsoft's support documentation lists the four modes. They are PC screen only, Duplicate, Extend and Second screen only. Microsoft also says Extend lets you move items between screens.
Butler plays retro games on the CRT alone. At work he uses extended mode, with the CRT as a side screen for messaging or media.
If Windows doesn't show a display you've plugged in, Microsoft's documented fix on Windows 11 is a short sequence. Open Settings, go to System, then Display, expand Multiple displays and choose Detect. The Identify button numbers each screen, which helps when one is an old CRT.
Display output versus rendering
The most interesting claim is that games shown on the CRT, through the iGPU's VGA output, can still be rendered by the RTX 4070 Super. Butler says he plays Cyberpunk this way. He doesn't want the iGPU's two compute units doing that work.
Laptops with hybrid graphics work on the same principle. The discrete GPU renders and the frames are passed to a display wired to the other GPU. In general this costs some overhead, but Butler doesn't measure it. He gives no frame rates, latency numbers or test method, and the two GPUs don't pool their performance.
Butler says his PC is always in high-performance power mode, so Windows picks the RTX card for 3D games. That is his observation. It isn't a guaranteed default for every game or system.
Choosing the GPU yourself
If Windows picks the wrong GPU, Microsoft documents a per-app control. On Windows 11, go to Settings, then System, then Display, then Graphics. Select the app under custom options and choose Options. Microsoft's page names three graphics preferences for PCs with more than one GPU:
- Let Windows decide (Power saving)
- Power saving
- High performance
Save the choice and restart the game or app. Butler doesn't say he used this setting. It is the supported route if a game lands on the iGPU.
Windows' GPU preference reportedly overrides global choices made in the NVIDIA and AMD apps, according to a recent XDA Developers guide. XDA says the Windows 11 GPU preference overrides both NVIDIA and AMD control panels, so Windows respects a per-app override even when a global preference is set in the NVIDIA App or AMD Adrenalin. Check that setting first if a game ignores your driver-side choice.
Another guide on the same topic says the NVIDIA Control Panel's preferred processor setting applies only when Windows has no preference for an app. That guide says the NVIDIA Control Panel's preferred graphics processor setting is used only when Windows has no GPU preference for the app.
Two vendors' software on one disk
The usual advice when swapping an AMD card for an NVIDIA one is to scrub the old drivers with DDU. Butler expected trouble with Adrenalin and the NVIDIA app both installed and running. He says they stayed in their own lanes. Neither overlay appeared on the wrong screen, and the two handed off cleanly in extended mode.
That reflects his machine on his driver versions, which he doesn't list. Future driver updates could change it.
The one reported problem: Chrome
He hit one failure. Google Chrome running on the AMD GPU crashed the driver. Turning off hardware acceleration in Chrome fixed it for him.
Treat that as a test, not a diagnosis. The root cause, the Chrome and driver versions, and whether others can reproduce it are all unknown. If you see similar browser-related driver crashes on an iGPU, try disabling hardware acceleration. Turn it back on if it doesn't help, because it benefits ordinary browsing.
What to weigh before copying this
- iGPU memory. AMD's own guidance, as relayed in the research notes, treats the UMA frame-buffer setting as best left on Auto for most users. AMD also says desktop users with both an iGPU and a discrete card may consider disabling the iGPU for a better gaming experience. Butler keeps it on for a specific hardware reason, the VGA port. That isn't a general recommendation.
- Dynamic memory. Butler says Windows will give the iGPU more memory if it needs it. The BIOS reservation and Windows' shared-memory behavior are different things. His 512MB figure is what he chose, not a requirement.
- Board dependence. He says a better AM5 board probably won't have a VGA connector. He'd then go back to an adapter.
- Alternatives. An active DisplayPort or HDMI-to-VGA adapter on the discrete card avoids the dual-GPU question altogether. Butler's reason for going without one is a wish to remove an adapter. I haven't tested any adapters.
The takeaway
A motherboard video port can serve an old display while a discrete card handles demanding games, and Windows handles the arrangement without special software. Butler reports that it works on his Ryzen 7 7700 and RTX 4070 Super machine. Treat it as a possibility, not a promise. Verify your CPU, motherboard outputs and driver behavior before you plan around it.