Z390 Aorus Pro, weird issues after trying to add a NIC


Aug 22, 2004
My setup: Z390 Aorus Pro, i9-9900k, 32GB (2x16GB). Board has 2x256GB NVMe SSDs in it, a dual Realtek NIC in x1_1 slot, GPU in x16_1 and a (currently empty) m.2 expansion card in the bottom x16_3 (x4) slot. 2x2tb hdds, 1tb ssd on SATA ports. keyboard, mouse, headset, xbox 360 controller adapter on USB. Win10 Pro x64.

Prior to this, the only actual problem I've had was when first setting up the system, where it would claim I didn't have enough USB resources available and my headset wouldn't work. Once system drivers were installed and updated this stopped and it seemed fine, although once the desktop loads I would hear the "USB device connected" noise.

I wanted to add two more ethernet ports to the system (I'm partly using this for some learning/work, and I wanted to give 4 VMs dedicated NICs on isolated networks) so I ordered two Dell 0FCGN Broadcom 5720 x1 slot dual NICs (one for this system, one for another).

Installing either Broadcom card in the available x1 slot (x1_3) would cause the system to only recognize a single DIMM: the DIMM in slot B1 would show up as only 128MB, and slot A1 would report correct size. Slots B2 and A2 would not function at all.

Thinking I had a failed DIMM I tried swapping them around (it's a 4x16GB kit, half in this system and half in another) but every DIMM that went into slot B1 reported 128MB, then showed 16GB when put in slot A1. With all four slots occupied (or memory in just A2/B2) the system wouldn't POST at all, it would get stuck in a loop where the display never initialized.

I tried rearranging the cards (putting just the Broadcom card in x1_1 with nothing else; moving the Realtek card to x1_3 and putting Broadcom in x1_1, even put the Broadcom card in x16_3, the bottom x4 slot), and no combination would work. Maybe it was a PCIe lane thing, so I put an x1 wifi card in x1_3, with the Realtek in x1_1, and... no issues with the memory. All seemed fine.

So right now I've got two Broadcom NICs, neither of which work in any combination in this system. OK, maybe they're both bad, I can test them in my other box when I get it reassembled. But it's also a Gigabyte Z390 board so I'm not expecting any different behavior.

Except... now, when I boot into Windows, I've got some odd behavior. It takes about 20 seconds to log in after I type my password. About 30 seconds before desktop icons appear. Nearly two minutes after that before the taskbar starts responding (keyboard works fine, but I can't click the start menu). Event logs are full of error 10010 and a few 10016. I get a 7000 error for bitlocker. I'm chasing these errors down the rabbit hole, but... they aren't in any of the logs until this.

Thing is, I never actually made it into Windows when these Broadcom cards were installed. The OS didn't even start booting, I just kept going into the BIOS to troubleshoot.

Maybe a Windows reset will help fix it but I can't pinpoint anything that would have caused the OS (which never attempted boot when the problem cards were installed) to have issues.

I haven't exactly been thrilled with the board (lack of RGB management in BIOS, the aforementioned USB resource error message, now whatever this is) and I'm starting to think maybe I should just try a different board, or just sell the whole setup and sit on my hands until Ryzen 3 lands.

Have any of you seen something like this?


Jan 16, 2013
Wow man that is weird. I think maybe you ought to contact gigabyte and get a replacement board.


I Drive Myself to the [H]ospital
Jan 28, 2014
"Once system drivers were installed..."
Was this not the first thing you did when you put the PC together? Did you install all the other drivers for the motherboard?

I think you ran out of lanes. Populating the x16_3 slot is putting you over budget, which is why you could boot into Windows when you took the expansion card out of that slot. The issues you are having after playing around with the setup may be due to not properly installing all drivers, in which case you probably need to start with a fresh installation of Windows.

If I'm not mistaken, the PCI-E lane distribution in your setup is working like this:

x16_1 = x8 CPU
x16_3 = x4 Chipset
x1__1 = x1 Chipset
M2A = x4 CPU
M2M = x4 CPU
SATA = x4 Chipset
Total = 25 lanes being requested out of 24 available

You can probably only use the x16_3 slot by itself or the 4 x1 slots together. Since you're not using the expansion card just leave it out. If you need all of those lanes you're going to have to "upgrade" to Skylake-X. The i7-9800X has 44 lanes from the CPU.


Aug 22, 2004
Furious_Styles I'm thinking about it, but since the system behaves mostly normally now I'm not sure I want to wait a month for Gigabyte to just say "nothing is wrong with it."

Armenius yeah, I didn't phrase that very well - it was a problem that happened on the fresh install, and as drivers were being installed/updated by Windows Update and Intel's driver utility the USB resource error fixed itself. I also noticed it when I installed a 2080ti, before drivers were installed, I guess because of the USB-C port on that? I don't remember seeing the error on previous system generations which is why I brought it up.

I hadn't thought of it being a lane limitation. But your math is off - the processor has 16 lanes, split between x16_1 and x16_2, and they run in an 8x8 config if both of those slots are populated. The chipset has 24 lanes, some devoted to onboard peripherals I think.

But with 2x NVMe SSD I'm at 8 chipset lanes in use, leaving another 16 for everything else. The extra slots, all populated, would only be another 6 lanes (two of the x1 slots and the bottom x4 slot). And I don't currently have an NVMe SSD in the riser card in the x4 slot, so those lanes aren't being used. At best I've got 10 chipset lanes in use by expansion cards.

I can add a wifi card to the open x1 slot and it works fine; if I remove it and the realtek dual-nic card from the other x1 slot and only install the broadcom card, it still doesn't work.

I considered doing an HEDT setup, but decided hold off and see what 3rd gen Ryzen/Threadripper brings to the table. I got nearly all of these parts in trades so they're really just acting as placeholders until I can build a proper "gaming/homelab" box. There have been some VERY tempting 2950x sales recently, though...