Question Are AM5 Mobo's with iGPUs a PITA ?

[Heat_Fan89]

Holy cow, it's been awhile since I dealt with an iGPU setup. The last time was with a Sandy Bridge gaming rig I built in 2013. Even that was mild when compared to the latest AMD iGPU's.

It's definitely a handshake problem between the iGPU and dGPU (RTX 5080). I'm using a Gigabyte B650 Eagle AX mobo and it's actually a very nice board but holy hell is it ever quirky if you start playing around with the BIOS. Today I made a change and enabled CSM and I could see both the i/dGPU's fighting with each other as I got a signal, then lost the signal. Rinse and Repeat.

The workaround is to clear CMOS, remove the RTX 5080. Boot up into the BIOS, select iGPU instead of PCIe as the default signal. Then force the HDMI signal to the iGPU. Then I can insert the RTX 5080 but I have to use the HDMI port on the iGPU or else I lock things up and have to clear CMOS and start all over again. Quirky as hell. 🤓

 

[Lutfij]

Disable the iGPU in BIOS, disable CSM and and RTX 5080, you have what is known in the industry as the worst launch in Nvidia's history(which topped the Fermi series of GPU's, oddly enough), unless the drivers you have aren't acting up on you.

When posting a thread of troubleshooting nature, it's customary to include your full system's specs. Please list the specs to your build like so:
CPU:
CPU cooler:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:
Monitor:
include the age of the PSU apart from it's make and model. BIOS version for your motherboard at this moment of time.

 

[CountMike]

Holy cow, it's been awhile since I dealt with an iGPU setup. The last time was with a Sandy Bridge gaming rig I built in 2013. Even that was mild when compared to the latest AMD iGPU's.

It's definitely a handshake problem between the iGPU and dGPU (RTX 5080). I'm using a Gigabyte B650 Eagle AX mobo and it's actually a very nice board but holy hell is it ever quirky if you start playing around with the BIOS. Today I made a change and enabled CSM and I could see both the i/dGPU's fighting with each other as I got a signal, then lost the signal. Rinse and Repeat.

The workaround is to clear CMOS, remove the RTX 5080. Boot up into the BIOS, select iGPU instead of PCIe as the default signal. Then force the HDMI signal to the iGPU. Then I can insert the RTX 5080 but I have to use the HDMI port on the iGPU or else I lock things up and have to clear CMOS and start all over again. Quirky as hell. 🤓

IGPU is in the processor, MB just channels it to it's connectors. Except for getting picture during access to BIOS/UEFI when one of those is connected to a monitor at same, I can't see how could they "fight" with a DGPU. In Windows, you need drivers for each one and can set which one is default for OS and change to what you want or even use at same time with 2 monitors.

 

[Heat_Fan89]

Disable the iGPU in BIOS, disable CSM and and RTX 5080, you have what is known in the industry as the worst launch in Nvidia's history(which topped the Fermi series of GPU's, oddly enough), unless the drivers you have aren't acting up on you.

When posting a thread of troubleshooting nature, it's customary to include your full system's specs. Please list the specs to your build like so:
CPU:
CPU cooler:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:
Monitor:
include the age of the PSU apart from it's make and model. BIOS version for your motherboard at this moment of time.

My apologies, I should had added /v or indicated that I was venting. There is a workaround and once the workaround works, the issue never occurs again. I have listed my complete system specs in other threads. This IMHO issue is probably down to the motherboard BIOS level and I have a feeling that it will require Gigabyte to address this in a BIOS update. That's if they so choose too down the road.

It is a handshake error as the POST built in diagnostics will flag a VGA error and trip the VGA error LED on POST. The Gigabyte motherboard has 4 diagnostic LED's. In this case since it can't output a signal it flags an error. At that point the system will not proceed to load the OS. I am stuck at the motherboard which requires pressing the power button and the PC immediately turns off.

Once the system is running it has been exceptionally stable. While others have had issues with Nvidia 5 series GPU's and driver issues. I have had none and I have always used the latest Nvidia drivers. I have not encountered black screens, lockups, or heat related issues.

I built my rig for Microsoft Flight Simulator 2024 and I consistently get 60FPS in 4K. It is ultra smooth. The CPU and GPU average temps are in the mid 40's. The CPU will momentarily spike to the low 70's when the game initally loads the airport and the ASUS TUF 5080 will get as high as 56c during that sequence as well. Once that has taken place the temps sit in the mid 40's.

 

[Misgar]

My RTX4070 and the iGPU in my 7950X on an Asus mobo seem to coexist quite happily under Windows 10. Although I boot up into the 4070, when I check GPU use in CPUID HWMonitor, I can see both GPUs working in video rendering programs (performing OpenGL/CL operations). Only one GPU (4070) is outputting a signal to the display, but the iGPU is functioning too. I'm using NVidia's Studio Drivers, not Gaming Drivers.

Do you have an option in your BIOS to choose which GPU has priority or is it set to Auto. Setting one specific option e.g. PCIe card, instead of Auto or Internal (iGPU) might fix the problem. You might also check if there's an option to set the PCIe Generation level on the slot containing your 5080. If it's a Gen.5 GPU, try Gen.4 instead of Auto.

I enable CSM/Legacy boot on some systems with ancient LSI HBA SAS controllers, so the LSI Option ROM on the RAID card is visible. For "normal" modern systems I leave CSM switched off. Why did you enable CSM?

 

[Heat_Fan89]

My RTX4070 and the iGPU in my 7950X on an Asus mobo seem to coexist quite happily under Windows 10. Although I boot up into the 4070, when I check GPU use in CPUID HWMonitor, I can see both GPUs working in video rendering programs (performing OpenGL/CL operations). Only one GPU (4070) is outputting a signal to the display, but the iGPU is functioning too. I'm using NVidia's Studio Drivers, not Gaming Drivers.

Do you have an option in your BIOS to choose which GPU has priority or is it set to Auto. Setting one specific option e.g. PCIe card, instead of Auto or Internal (iGPU) might fix the problem. You might also check if there's an option to set the PCIe Generation level on the slot containing your 5080. If it's a Gen.5 GPU, try Gen.4 instead of Auto.

I enable CSM/Legacy boot on some systems with ancient LSI HBA SAS controllers, so the LSI Option ROM on the RAID card is visible. For "normal" modern systems I leave CSM switched off. Why did you enable CSM?

Yes I do! Once I am able to get video on the monitor, I can plug in the RTX 5080 and change things in the BIOS. I actually had the iGPU disabled in the BIOS. Everything was working until I started experimenting in the BIOS and enabled CSM by mistake. When I rebooted that's when the handshake problem arouse. At that point it becomes a hard error until I remove the 5080 and clear CMOS for the error.

I'm back in business after the workaround and I just decided to leave it set to iGPU and I just plug my HDMI cable into the motherboard connection. I still get the 5080 output from the motherboard HDMI connector.