No network or USB on Gigabyte 970A-D3P (970 chipset) fix on CentOS/RHEL 6.5

I recently went back with a AMD based system for my fileserver at home due to a friend that was upgrading and was going to sell me his fx-6100 at a great deal. During this I moved, as I always have, my Linux drives to the new hardware but this time I ran into several issues. They were

1) No network on either my E1000 (PCI add on card) or the onboard Realtek 8168. I saw some ARP weirdness but not connectivity or ping access to any hosts.
2) USB 2.0 throwing errors and not working (on all ports I tried…USB 3 did work)

Nothing fixed this till I did this :

1) Turn on IOMMU in bios
2) enable grub to take advantage of this via the following boot flag `amd_iommu=on`

Once that was added and a reboot performed all worked as expected.

Hope this helps save some google searcher some time!


  1. Snoosaphone says:

    That is exactly what I’ve been looking for. Having to move my KVM to USB 3 ports wasn’t working all that well and the fact that the network wasn’t working…

    Thank you very much for putting this out there.

  2. MisterX says:

    A year later and the update to Cent 6.6 and its new kernel has created issues for USB on this setup again.

    I am currently playing with ways to fix…if someone has a issue with USB still ping me and we can compare notes.

  3. JamesTQuirk says:

    iommu fix, worked for Xubuntu 14.04.1 LTS, on Gigabyte 970A-D3P Motherboard, running FX8350 Black 4.0ghz, 32gb ddr3 ram, Gigabyte HD 5450 Vid….

    Prior to adding bios & Grub fixes, had all the symptoms people mention, flaky usb, no net, sluggish transfers on SSD, 500kbs transfer between internal rust spinner hard drives (sata3), but once fixes were applied ALL GOOD !!!!

    Internet starting working, USB 3.0 worked, and I didn’t have to keep swapping ports on keyboard & Mouse to get some action, on internal ssd partitions getting up to 50-60 meg per sec (depending on file types/size), 45-55meg per sec on spinner Hard Drives, So real happy with the suggestion here, it worked for me !

    Thanks ….

  4. MisterX says:

    Thanks for the feedback, its much appreciated.

    Do you know what kernel you were running per chance ? Are you on a V1 or V2 of the motherboard ?

    I did note on the Gigabyte there is a new BIOS for these systems. Don’t know if it helps any of these issues but I might give it a try soon.

    UPDATE : Its a beta bios…but here it is (NOTE THERE ARE 2 VERSIONS OF THE MOTHERBOARD!)
    might wait till its vetted and released as a non-beta bios.

  5. JamesTQuirk says:

    Operating System Version
    Kernel Linux 3.13.0-43-generic (x86_64)
    Compiled #72-Ubuntu SMP Mon Dec 8 19:35:06 UTC 2014
    C Library Unknown
    Default C Compiler GNU C Compiler version 4.8.2 (Ubuntu 4.8.2-19ubuntu1)
    Distribution Ubuntu 14.04.1 LTS

    Motherboard is a REV 1.0

    Date 08/06/2013
    Vendor American Megatrends Inc. (
    Version F5
    Name 970A-D3P
    Vendor Gigabyte Technology Co., Ltd. (

    ATA Samsung SSD 840
    ATA ST2000DL001-9VT1
    ATA ST32000542AS

    I have downloaded F6f bios from gigabyte, i am still ironing out issues here with networking between xubuntu & winblows7, but I am sure it’s just config, may look to update, but as its a beta I may wait to see if I can get this system stable with current bios as u can see also I have 3 different HD brands in box, so maybe the next thing is get 2 5TB’s of same brand as ssd… but I may have to settle on 2 WD WD50EFRX 5TB Red 3.5” IntelliPower SATA3 NAS HDD …

    See what happens …

    and thanks again for that fix, MisterX

  6. MisterX says:

    Sure …If you want some help with your network issue let me know always glad to help where/when I can.

    On your drives you can use hdparm -I to get detailed info about their setup. If you are behind a raid controller it might get trickier but, like everything in Linux, there is more than one way to solve a problem.

  7. JamesTQuirk says:

    Well glad I didn’t get networking issue fixed, I have 2 networks here, REAL HOME, and internet available, I have for the longest time only transfer files between 2 Nets Via USB, was going to do a link to save some time, but friday, while transconfigurating some video on xubuntu, watching my main ONLINE machine, its online a bit, Transfer Time: 178 Days 15:52 Hours (99.8%), WIN7, slipstreamed to DVD, booting from DVD, running in a sandbox, but on the real WIN7 dualCrap Lappy, But it got knocked offline, but not compromised.

    However, MY DV6 I7(8C) 16gb ram, starting going nuts, all fans got ready for take off, thought trackpad was gettin ready to cook a egg, I go, “what u doin”, Process explorer found Cryptolocker & siblings @ work, Killed them & Descendants, msconfig, got them out of startups, I shut it down, Pulled that HDD, replaced with a spare, Reinstall backup win7 on it, but with CLAMWIN, I use ClamTK on xubuntu, but was trying it in slipstreamed machine, and it locked up the connection, before getting in, But DV6 was used Win Essentials, Housecall’s, Malwarebytes …..

    So I have this 320GB I pulled from, DV6 Lappy, with cryptolocker half way thru it’s nasty, as a ext usb under Xubuntu, I still have full access to files on HDD, as it appears the trap was not sprung …..

    So being looking @ that, disassembling it, hopefully if I can work out how it talks to them, I could send it back to them, dressed as the message they are expecting, with several more zeros @ end, but it it traceable part of it’s trail goes to TOR network, there I am Stuck …

    So maybe the USB transfer may just have to stay ….

  8. JamesTQuirk says:

    Uuuuuund, Merry Christmas, I got the bugger I hope, it came to last night, I made a .ISO out of 320gb, run in a VM under linux, let it run it’s course, with me watching, about a hour ago the VM got the demand, BUT I was watching VM whole time, I Have them now …..

  9. MisterX says:

    Happy hunting! Never dealt with cryptolocker so not much help there.

  10. JamesTQuirk says:

    Just to show how slow my xmas is, I decoded their “communications channel”, & hopefully I sent “them” the reply, “they” expected, except it will depack into their Cryptolocker, & I added several million zero’s to ransom .. Unfortunately it goes to TOR IP so, only a maybe ….

  11. JamesTQuirk says:

    But as of today, it seems all attacks on machine have stopped since 26th dec …….
    hope it worked, and they pay up …. ;)

  12. MisterX says:

    Sounds like you had a interesting holiday!

  13. benny says:

    Hi, i have the following issue.
    I’ve tried to install centos on my pc and the installer throw the following error:

    Formatting Failed
    An error was encountered while formatting device /dev/sda1
    Details: invalid device especification

    What can be wrong with that ?, because i have installed the same centos on another pc with intel processor, and that if it works

    PC details:
    motherboard – gigabyte 970a d3p
    processor – amd athlon II x2 245
    ram – kingston 4GB 1600
    hd seagate barracuda 1tb

  14. MisterX says:

    Benny this is a little off topic and likely served in a different location for faster response.

    With that said I would change the console session during the install and see what it thinks your drive is (if it even sees it). Then take that information to a site like or or even the CentOS forums.

    Sadly I do not update my site frequently enough to recommend anyone use it as a means of expedited troubleshooting beyond what is in the posts.

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