The system is unable to publish without a GPU installed.
The system is unable to publish without a GPU installed.
Hello! I'm just starting out with my first build and running into some trouble. The setup includes: Mobo: B760I Aorus Pro [new link] CPU: Intel i7-14700K [new link] Power supply: Corsair SF750 80+ Platinum [new link] RAM: Corsair Vengance 64Gb (2x32) DDR5 6400 [new link] Cooler: DeepCool LT720 360mm AIO [amazon link] GPU: MSI Ventus 3X 4080 Super [best buy link] When I don't connect the GPU and instead use the HDMI output on my monitor, everything functions properly. I've managed to update the BIOS there, but that didn't resolve the problem. Plugging in the GPU and turning it on makes a clicking sound from the PSU (normal) yet no fans spin up—no LEDs light up on the motherboard. I'm not sure if this board lacks debugging indicators. I've tried: * latest BIOS (F8), * connecting GPU to PCIe slot but using integrated graphics, * plugging monitor into integrated mode, * changing PCIe settings, * moving GPU cables between CPU and GPU ports, * switching protocol to PCIe gen 4, * gently adjusting the GPU cable while booting, * swapping the 8-pin ports on the PSU. Despite these attempts, nothing works. I'm unsure if this is typical behavior. It's also puzzling that the system remains silent when powered on—no fans at all. Since this is my first build, I don't have other components to test or another machine to try it on. Possible next steps: 1) Add a motherboard speaker to hear any tones, 2) Install Windows and set up the GPU through integrated graphics, 3) Try a different GPU with a 3x8 pin splitter cable, 4) Check if the PSU has the right connectors for my setup, or 5) Send the GPU back for repair. I've attached a picture of my BIOS.]
I believe a 750W power supply isn't enough to run the entire PC, as it can operate without the GPU's power needs. Also, your power consumption on PCCP picks is 680W, which is higher than what a 750W PSU would handle.
It's cool you found others who had similar experiences. The PC component seller mentioned it was fine, so you went ahead and purchased the power supply. Maybe you just wanted extra capacity? Understanding how much headroom is typical can help avoid surprises later.
I found some interesting points here. The 4080 Super Ventus should feature a 12-pin PCIE 3.0 connector on the graphics card, not 8-pin ones. It’s hard to tell if the image you saw is your setup or the monitor, but there are many artifacts on the BIOS main page. I’d suggest removing the CPU and inspecting the socket pins—this is up to you. This approach won’t stop the system from posting. The graphics card itself doesn’t have a built-in feature to verify power supply size, so it won’t prevent power from coming on; a lower wattage PSU will simply fail under load.
The 14700k reaches up to 181W with strong overclocking, while the 4080 Super tops out at 402W. It seems you’d need around 300W of headroom just to run, but I’m open to your explanation.
Edit: Make sure you’re using the right cables. Your PSU includes two for the CPU and two for the graphics card. Graphics cards only use the PCI-E labeled ones—you’ll need to connect them in a chain, which is acceptable.
Interesting! You're currently not near your build space, but it seems you might be using a CPU PSU cable for the GPU setup. The GPU came with this cable, along with a note about connecting separate PSU cables to each of the three branches—no daisy chaining. Should I use the three 6+2 PCIe cables for the GPU instead of the extra CPU one?
Uncertain how they designed the setup with two 4+4 CPU cables and just two 6+2 PCIe connectors. You'll need to switch one of the PCIe cables onto the third connector of the adapter (marked in red) and connect it there. The GPU won't boot unless all three adapter connectors are filled. It seems the PSU is operating near its maximum capacity—during testing it reached about 300W, which is close to the limit. The minimum power rating listed by MSI is 750W, so running a stress test is recommended right away.
Since the connection on the PSU side matches, but differs on the other end, one side is marked as CPU or EPS while the other is PCIe. Avoid swapping them without understanding the differences. For the GPU, it's fine. But keep in mind you'll need to stress-test the PSU significantly—better start right away. It’s beneficial that it has a Platium rating, since it will typically operate near 90%+ load under normal conditions. Both the PSU and GPU come with protective features, ensuring safety.
Consider your needs carefully. An 850W PSU might suffice, but a 1000W or higher ensures reliability and future-proofing.