6 GPU System will not boot with all GPUs plugged in

[c0nsole]

I'm building a 6 GPU rig with an Asus Z270-AR. All of the GPU's are connected to the motherboard via USB PCI 1x to 16x riser cards, powered by molex connectors.

I've been doing some testing, and I can sometimes get it to boot with 5 out of the 6 GPU's fully functional. The strange thing is that it isn't one single GPU that makes it not boot, it seems to be that it just can't do all 6 at once. When unplugging them and restarting the pc one by one, I found that in most of the cases, 5 GPU's still doesn't work, but every few times, it will work. Using only 4 GPU's always seems to work.

Then, when I unplug all the others and just test the one that turned out to be the problem, it works totally fine. When I plug in all 6 at once again, it doesn't work, and this time a completely different GPU is determined to be the problem. When I test that one alone, it is also totally fine.

The screen I see when it fails is this: http://i.imgur.com/cRgiaqT.jpg
Windows is already fully installed and functional, and when I reduce the amount of GPU's it boots correctly. When I press escape as it suggests, it simply restarts the machine and brings me back to the same screen.

I'm at a loss, power definitely shouldn't be an issue since I have a beefy 1200W power supply and these are quite efficient GTX 1070's. The cards all light up and their fans spin so they all have power.

Also, this rig does not have a case, it is just a motherboard, CPU, an SSD, and GPU's in open air.

Thanks in advance for your effort.

 

[DRagor]

PSU directly gives only 12 V power to those GPUs, while they need also 3V delivered by motherboard. With so many of them, motherboard may not be able to deliver enough for each one.
Try to decrease amount of power motherboard uses: in BIOS turn off on-board LAN, sound card, every device you can live without; reduce PCIe slots from Gen3 to Gen2 or even Gen1.

 

[tsnor]

Your config seems like this one: http://www.coinminingrigs.com/how-to-build-a-6-gpu-mining-rig/

IS your power supply a single rail, or multiple rails? If multiple have you balanced the load over the video cards ? Each of those six 1070s expects 50-75W from the MB PCI connector -- you are supplying this power via the PCI 1x to 16x riser cards hooked into sata cabes - is this load spread out over multiple rails? Each of those 1070s also takes external power - again spread over multile rails. I wonder what the in-rush current flow is for the 6 video cards and how low that drops voltage. https://en.wikipedia.org/wiki/Inrush_current

If you have a spare PSU you can temporarily connect the 2 extra 1070s to the second psu using this thing to provide a common ground.. $16 https://www.amazon.com/Add2PSU-Multiple-Power-Supply-Adapter/dp/B009P98Q8U

Can you post make/model of your PSU ? Not all 120oW PSUs deliver 1200W. (assuming this is for mining, and that you bought a high end efficient 1200W PSU to save money, but you never know).

Neat project. Post when it works. Have you tried the 5 card config (when it boots) under load ?

 

[BadActor]

MERGED QUESTION
Question from c0nsole : "Asus Z270-AR Won't Post"

Hey guys. I just finished up a rig today with an Asus Z270-AR motherboard and a i3-7100.

It seems like the system won't post. Or at least that's my best guess. I've never built a system before but it simply goes to what looks like a blank cmd window with a blinking line where you would normally be able to type and sits there forever. All of the fans on the system spin, including the CPU cooler. The MoBo light is solid green, its RGB is fully functional.

In other words, everything on the system is fully functional, and if you didn't look at the screen, you'd never know it wasn't fully working.

When you do look at the screen though, it does something weird. When I first booted it up, it correctly identified everything I had installed. It listed the CPU, RAM, Storage, and everything, saying at the bottom of the screen that the CPU cooler was plugged into the wrong place(it was) and that I could press F1 to begin setup. When I did that, it wen't to the blank screen I mentioned.

When I turned off the system and plugged the CPU cooler into the correct place, it skipped this screen entirely and went to the blank screen.

The manual says I should hold Del or F2 to boot into setup but I've tried that plenty of times and it doesn't work.

Based on the sticker, it looks like the motherboard is running on bios 0604, though I can't imagine its a CPU compatibility issue since the MoBo and CPU came out around the same time(I Think).

Any ideas would be much appreciated it.



EDIT: It seems it only fails to post when my GPU is plugged in. Even when it is plugged in, my monitor is connected directly to the motherboard since I am booting up for the first time- am I doing something wrong? I've never set up a GPU before so maybe I'm missing something.

Couple of things. Unplug the PSU from the wall, then remove the CMOS battery and press and hold the case power button for a minute or two to completely discharge the motherboard. Remove the GPU from the motherboard, and plug you video cable into the motherboard. Then replace the CMOS battery and plug the PSU back in. Try booting. If it boots, then you can install the graphics card again, making sure it's in the proper slot, fully seated, and the PCIe connectors attached if it has them.

Couple of things. Unplug the PSU from the wall, then remove the CMOS battery and press and hold the case power button for a minute or two to completely discharge the motherboard. Remove the GPU from the motherboard, and plug you video cable into the motherboard. Then replace the CMOS battery and plug the PSU back in. Try booting. If it boots, then you can install the graphics card again, making sure it's in the proper slot, fully seated, and the PCIe connectors attached if it has them.

What I failed to mention is that this rig is 6 GPU's. I've been doing some testing, and I can sometimes get it to boot with 5 out of the 6 GPU's fully functional. The strange thing is that it isn't one single GPU that makes it not boot, it seems to be that it just can't do all 6 at once. When unplugging them and restarting the pc one by one, I found that in most of the cases, 5 GPU's still doesn't work, but every few times, it will work.

Then, when I unplug all the others and just test the one that turned out to be the problem, it works totally fine. When I plug in all 6 at once again, it doesn't work, and this time a completely different GPU is determined to be the problem. When I test that one alone, it is also totally fine.

I'm at a loss, power definitely shouldn't be an issue since I have a beefy 1200W power supply and these are quite efficient GTX 1070's.

Also, this rig does not have a case, it is just a motherboard, CPU, an SSD, and GPU's in open air.

Thanks in advance for your effort.

6 GPU's! That may have an effect on your problem, lol. Hazarding a guess that the i3 simply isn't up to the task of pushing that many graphics cards. If you have access to an i7, I would swap that in and see if that solves your problem. Also, how much RAM do you have?

 

[tsnor]

MERGED QUESTION
Question from c0nsole : "Asus Z270-AR Won't Post"

Hey guys. I just finished up a rig today with an Asus Z270-AR motherboard and a i3-7100.

It seems like the system won't post. Or at least that's my best guess. I've never built a system before but it simply goes to what looks like a blank cmd window with a blinking line where you would normally be able to type and sits there forever. All of the fans on the system spin, including the CPU cooler. The MoBo light is solid green, its RGB is fully functional.

In other words, everything on the system is fully functional, and if you didn't look at the screen, you'd never know it wasn't fully working.

When you do look at the screen though, it does something weird. When I first booted it up, it correctly identified everything I had installed. It listed the CPU, RAM, Storage, and everything, saying at the bottom of the screen that the CPU cooler was plugged into the wrong place(it was) and that I could press F1 to begin setup. When I did that, it wen't to the blank screen I mentioned.

When I turned off the system and plugged the CPU cooler into the correct place, it skipped this screen entirely and went to the blank screen.

The manual says I should hold Del or F2 to boot into setup but I've tried that plenty of times and it doesn't work.

Based on the sticker, it looks like the motherboard is running on bios 0604, though I can't imagine its a CPU compatibility issue since the MoBo and CPU came out around the same time(I Think).

Any ideas would be much appreciated it.



EDIT: It seems it only fails to post when my GPU is plugged in. Even when it is plugged in, my monitor is connected directly to the motherboard since I am booting up for the first time- am I doing something wrong? I've never set up a GPU before so maybe I'm missing something.

Couple of things. Unplug the PSU from the wall, then remove the CMOS battery and press and hold the case power button for a minute or two to completely discharge the motherboard. Remove the GPU from the motherboard, and plug you video cable into the motherboard. Then replace the CMOS battery and plug the PSU back in. Try booting. If it boots, then you can install the graphics card again, making sure it's in the proper slot, fully seated, and the PCIe connectors attached if it has them.

Couple of things. Unplug the PSU from the wall, then remove the CMOS battery and press and hold the case power button for a minute or two to completely discharge the motherboard. Remove the GPU from the motherboard, and plug you video cable into the motherboard. Then replace the CMOS battery and plug the PSU back in. Try booting. If it boots, then you can install the graphics card again, making sure it's in the proper slot, fully seated, and the PCIe connectors attached if it has them.

What I failed to mention is that this rig is 6 GPU's. I've been doing some testing, and I can sometimes get it to boot with 5 out of the 6 GPU's fully functional. The strange thing is that it isn't one single GPU that makes it not boot, it seems to be that it just can't do all 6 at once. When unplugging them and restarting the pc one by one, I found that in most of the cases, 5 GPU's still doesn't work, but every few times, it will work.

Then, when I unplug all the others and just test the one that turned out to be the problem, it works totally fine. When I plug in all 6 at once again, it doesn't work, and this time a completely different GPU is determined to be the problem. When I test that one alone, it is also totally fine.

I'm at a loss, power definitely shouldn't be an issue since I have a beefy 1200W power supply and these are quite efficient GTX 1070's.

Also, this rig does not have a case, it is just a motherboard, CPU, an SSD, and GPU's in open air.

Thanks in advance for your effort.

6 GPU's! That may have an effect on your problem, lol. Hazarding a guess that the i3 simply isn't up to the task of pushing that many graphics cards. If you have access to an i7, I would swap that in and see if that solves your problem. Also, how much RAM do you have?

1, Its a mining rig. He doesn't need cpu
2. slow cpu would not drop video cards from avail list, i3--> i7 doesn't change that
3. it does post, it boots to windows, it just doesn't have all 6 video cards available for mining.