[PC] Forza 7 selecting secondary GPU instead of primary GPU

Troubleshooting Hub Legacy Troubleshooting Legacy Motorsport Issues
1

Summary
I was getting some pretty bad frame rates and stuttering even on medium 1080P. Unlike with every other game I push setting to max, my AMD R9 390 8GB vram (primary GPU in first PCIe x16 slot on motherboard) was not spinning up like a jet engine, so I did some investigation: My GTX 660 2GB used for extra HDMI ports and CUDA cores for apps was under full load. Every other game I’ve ever played on this setup uses the R9 390 by default. Forza 7 doesn’t.

Setup
Forza 7 Version: 1.107.1807.2
Windows 10: Fully updated
Radeon Drivers: 17.9.3 (updated last night)
Geforce Drivers: 385.69

ASUS Sabertooth X99 motherboard | i7-5820K @4.5GHz | 16GB RAM
PowerColor R9 390 8GB (PCIe x16 slot 1) and EVGA GTX 660 2GB (PCIe x16 slot 2)

Investigation
I booted up MSI Afterburner to watch the clockspeeds of my GPUs while Forza 7 benchmark was running on a separate monitor. The R9 390 idles at ~300mhz and maxes out at 1010mhz (default) or 1150mhz (my overclock). While running the benchmark, on ultra + dynamic everything + 1080P, I got an average frame rate of about 4fps. My R9 390’s core clock did not waver past idle.

I changed the focused GPU in MSI Afterburner to my GTX 660. This card idles at 324mhz. When I restarted Forza 7 and reran the same benchmark, the core clock jumped to 1188mhz and above. Same result on benchmark.

I quit Forza 7, manually disabled my GTX 660 in the device manager, and restarted Forza 7 and reran the same benchmark. In MSI Afterburner, I saw that my R9 390’s core clock jumped to around 1150mhz, and I got a solid 59.9fps in 60fps V-sync mode (ultra + dynamic everything + 1080). My menus also stopped stuttering like trash, and the game became more responsive.

Follow up Stability Testing
I created an AutoHotkey script to emulate key presses going through the main menus (up/down/left/right esc and enter). I’ve had stability issues in menus before where it would crash. I ran this on the GTX 660 for a period of 8 hours, and came back to a crash. I “fixed” the GPU selection as described above and reran it overnight. I woke up to it happily navigating the menus randomly. I think the key issue I was having stability-wise was this incorrect GPU selection. I’m glad because I was getting kinda frustrated.

Suggestion
Team 10, please have Forza 7 detect the default/primary GPU and not a random one. At the very least, let us pick which one in the menu or via startup options. It’s rather unnecessarily inconvenient to disable my secondary GPU everytime I want to play Forza.

2

i have the same problem:

i5 2500k
asrock p67 PRO3 which hasn’t intel HD chipstet
7970hd

i have a black screen but i still have sound when i launch the game

3

Hope this helps.

4

wanted too say im also facing this issue also… even with forza motorspot 7… If i have more than one card in my system yes i use one for mining… The dam games always pick the gpu in the 3rd pcie slot and it also shows the game being display on the first pcie slot gpu… I nailed it down its doing this cause the first gpu doeisnt have any load while the 2nd one in the 3rd pcie does.

And the game is very laggy till i turn off mining on it than it goes smooth.

While every other dam game works perfect and picks the first pcie slot gpu???

[Mod Edit - Abbreviated profanity, profanity and profanity that is disguised but still alludes to the words are not permitted - D]