I installed a PNY RTX 5080 OC in a system with an MSI B450 Gaming Plus Max motherboard, a Ryzen 7 processor, and two Trident Z RAM sticks. The system works normally with my RTX 3080, but after swapping in the 5080, the monitor no longer detects a signal. The HDMI cable is fine because the 3080 works immediately when reinstalled, and I also removed the previous display drivers.
The new card's fans and lighting start up, so I initially suspected the power supply or cable arrangement. I'm using a Cooler Master 750W MasterWatt, while the card recommends an 850W or larger unit. The 5080 also uses three power connections, whereas the 3080 used two. All three are connected, but two come from the same cable bundle using a piggyback connection. Should each connector use its own dedicated PSU cable? I also noticed three metallic-looking pins beside the card's power connector, but the manual doesn't explain what they do.
2 Answers
I’d upgrade the power supply before doing much more troubleshooting. The card powering on doesn’t necessarily mean the PSU is providing enough stable power for it to initialize properly. Since this is the OC model and the manufacturer recommends at least 850W, use a quality unit that meets or exceeds that recommendation, with the correct number of dedicated PCIe power cables. I’d stick with the 3080 until the PSU is replaced.
Avoid relying on a piggybacked or daisy-chained connector for a card this power-hungry. Each power input should ideally run from its own proper PSU cable, and the PSU itself should have the recommended wattage, suitable connectors, and good build quality. A higher-wattage unit may also give you more room for future upgrades, but don’t keep testing the 5080 with an undersized setup if you can avoid it.
Thanks, I’ll use the 3080 for now and replace the PSU with one that has enough dedicated connections.
That makes sense. The fans and lights starting up had me thinking the power delivery was sufficient, but the higher recommendation for the OC version is probably important.