Intel Motherboards - Utilizing all 5 PCIe slots on H81 Pro BTC

Utilizing all 5 PCIe slots on H81 Pro BTC

Printed From: ASRock.com
Category: Technical Support
Forum Name: Intel Motherboards
Forum Description: Question about ASRock Intel Motherboards
URL: https://forum.asrock.com/forum_posts.asp?TID=3109
Printed Date: 12 Mar 2025 at 7:32pm
Software Version: Web Wiz Forums 12.04 - http://www.webwizforums.com

Topic: Utilizing all 5 PCIe slots on H81 Pro BTC

Posted By: Wits
Subject: Utilizing all 5 PCIe slots on H81 Pro BTC
Date Posted: 25 Jul 2016 at 10:32pm

Good Morning,

This might be a complete noob question and if so I apologize upfront.

I am having a problem getting 5 cards to register properly on this board simultaneously. I have been able to get 4 of them to register in the device manager and function properly but the 5th either shows up with a driver splack (that in turn requires a reboot), or it shows up as a hidden device.

To further explain my setup, I am running two EVGA Supernova 1000w Ps power supplies, 4 MSI R9 390x GPUs (3 of them are using riser boards and cables, 1 of them is plugged directly into the PCIe 16-pin port), 16GB of RAM, and a 3.2ghz pentium processor. The O/S is Win10 Pro. Running this setup everything functions normally and is mining well at 128 Mh/s.

However, I have additional cards that I would like to utilize if possible. Is there a trick to utilizing all 6 ports simultaneously?

In addition, I could not find any solid information about how to hook up the two 4-pin power connectors. Can someone please shed some light on this for me?

Replies:

Posted By: vacaloca
Date Posted: 26 Jul 2016 at 8:57pm

As per your motherboard's manual:

(4-pin SLI/XFIRE_PWR1 & 4-pin SLI/XFIRE_PWR2)

"Please connect these connectors to the power supply when three graphics cards are installed on this motherboard." (they mean three or more, really)

These are 4-pin molex connectors. I can't imagine your power supplies don't have molex connectors, but if not, just get an adapter. This by itself might be why your last card isn't working properly when all the other ones are connected.

After connecting these power cables, if the last card doesn't work, see if the problem follows the card or the slot -- i.e. interchange a known working card to the slot that is giving issues and see what happens... if the card works in the other slot, then you know the slot is not the problem.

Sometimes when fully populating all PCI-E slots in a motherboard strange issues pop up, given that configurations like this are (IMO) rarely tested by BIOS QA. If you still have issues after connecting the power cables and it's not a slot issue, might want to send a support inquiry here: http://event.asrock.com/tsd.asp" rel="nofollow - http://event.asrock.com/tsd.asp