Quote from: gribgo on August 31, 2016, 06:20:42 PM

Quote from: d57heinz on August 31, 2016, 03:40:44 PM

Quote from: jammer81 on August 31, 2016, 09:41:21 AM

Quote from: Trimegistus on August 31, 2016, 08:37:29 AM

Quote from: megaplage on August 31, 2016, 06:47:02 AM

Quote from: Trimegistus on August 31, 2016, 06:18:20 AM

Quote from: Trimegistus on August 31, 2016, 12:08:06 AM

Guys,

I'm having a hard time getting my new rig to boot Huh

MOBO: Asrock H81 Pro BTC
GPU: 6 x Rx 480 Sapphire Nitro 4Gb
PSU: 2 x Corsair 850 W
OS: Win10 x64

I have two molex connectors powering the mobo with extra juice and I'm not using powered risers.

Everything was running great with the previous video cards (R9 270) but now I can only get the mobo to boot with 3 video cards, and one has to be directly connected to the 16x PCIe.

Isn't it strange? I have extra power available and besides, the old video cards were consuming more power than these new ones.

Any ideas?

Change UEFI settings? Anyone messing with the Gen1/Gen2 setting?

Anything else?

I have another 6x480s coming soon!

Any help will be greatly appreciated Undecided

Thank!

C'mon guys, a lot of you are using the 480 + H81 BTC Pro.

How do you manage to use 6 x 480 on this motherboard?

use powered risers for more than 2 cards

Do you mean I need to use powered risers when using more than 2 cards?

Humm... I've seen a lot of people complaining about the use of powered risers claiming they cause instability problems.

I have a few 1x to 16x powered risers and I'll give it a try. Fingers crossed Tongue

Stay away from the PCIE164P-M-BOARD VER:03 I had about 25 of these and 20 where intermittent and caused random reboots and POST failures.

i replaced with PCIE164P-M-BOARD VER:02's and PCIE164P-M-BOARD VER:05's And 110% stable ever since.

must have been some bad luck or i have really good luck.. All mine are ver 3 and have not had one single issue. Pd around 7.50$ avg pc. well over 30 and counting i never paid no attention to that till your post. But seems mine have been doing great. make sure if you can to not use the adapter for the power. use the molex if you can.

Best Regards
d57heinz

Using TWO PSUs on the same system is the issue IMO.

Nah, you can use 2 PSU on the same system no problem. You keep 1 power on all the time with the the motherboard shorter plug. The other will power on the system so no issues. All my rigs are that way and I have over 15 rigs as well as my friend who have 4.5GH. You can't power 6 x 290 or 390 without using 2 PSU even with a EVGA 1600 when dual mining, it's pushing too much. Regarding powering more than 2 GPUs, the advice to use power riser is correct. That's the best way to do it, else you can fry your MB. Each card PCIE can draw up to 75 watts or more before the driver update for RX480 so you multiply that by 6 and that's too much power to be asking from the MB. Do not buy the skinny risers with the floppy drive looking power connectors. They are very cheap and will burn out very easily especially when overclocking. Go for the fat MOLEX power risers. I threw away about 30 of the cheap skinny ones,never had issues with the FAT molex ones.

All my Motherboards are
H81 BTC pro - Don't need to plug Molex into Motherboard (optional and I don't do it) - Press N to disable future warnings

H97 anniversary - Requires Molex into MB for more than 3 GPU configs. H81 is better, these tend to have higher DOA based on my collective mining group's experience with combine hashing power of over 12GH.

MSI Gaming 5 - This is the only board where you have to mess with the BIOS settings. Change PCIE to Gen 1 for all first 3 on the list. The other setting below needs to be 8x/4/4 instead of default if you want it to work for all your 1x risers.