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PC Graphics

hoverbacon
Journeyman III

2 GPUs: only 1 card being used?

Specs:

Desktop

Driver Version: 18.4.1

2 x R9 390

AMD Ryzen 1600

8GB DDR4 RAM

MSI AM4 B350 motherboard (BIOS: MSI click bios 5)

Corsair Gold 850 Watt PSU

Display: AOC 2540x1440p IPS Panel

              Acer 1920x1080p monitor

Hi, I just discovered, only one of my graphics cards is being used, both definitely work and both are detected and show in device manager, and I can swap between them by plugging my main monitor into either card. When I run a game, if I look in Task manager or GPU-Z one card shows it is maxed out at 100% usage and the other shows 0% usage, GPU-Z also tells me this and that crossfire is disabled but there is no option to enable it in radeon settings. R9 390s do not need a crossfire bridge and there is no slot for one. I'm certain my motherboard supports crossfire/dual gpus or whatever, but I can't get the other second one to be used. MSI Afterburner shows the second card as "Synchronized with Master."

   I get the same fps after removing one of the cards, I also know the second one isn't working as I can hear the fans when it is working i.e.- when I reboot my PC or plug my monitor into it.

I have tried:

-Wiping and reinstalling drivers.

-Swapping the cards round.

-Looking in the BIOS but nothing shows up there about GPUs.

-Disabling ULPS in RegEdit

-Trying to enable crossfire but I have no option to enable it. (Spent ages looking online how)

-Getting really angry and hitting my desk really hard.

Thanks!

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6 Replies

Do you have an other expansion card in a PCI slot(some model mobos drop to pcix2, which won't run a second graphics card in crossfire).

Ryzen 5 5600x, B550 aorus pro ac, Hyper 212 black, 2 x 16gb F4-3600c16dgtzn kit, NM790 2TB, Nitro+RX6900XT, RM850, Win.10 Pro., LC27G55T..
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Yes, I have 2 PCIx16 slots, one 3.0 and the other 2.0. My motherboard explicitly states it supports crossfire,

Thanks!

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AH! no you're right, It says in radeon settings that the current bus settings are PCI Express 2.0 x2. The port is x16 and should say x16. My motherboard says explicitly on the box that it supports crossfire, how do I fix this?

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I have nothing plugged into any other pci slots, just the 2 graphics cards. But yes one of the slots has dropped to PCIx2. Apparently my motherboard type shipped with a faulty BIOS and couldn't run crossfire so I have just updated my BIOS to fix that, but the PCI slot is still throttled down to x2 so I still can't crossfire.

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Maybe contact MSI support/forum.

Ryzen 5 5600x, B550 aorus pro ac, Hyper 212 black, 2 x 16gb F4-3600c16dgtzn kit, NM790 2TB, Nitro+RX6900XT, RM850, Win.10 Pro., LC27G55T..
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Ok so I'm an idiot, I knew about the cards being slowed by stuff in the PCIe x1 slots but totally forgot my wifi card was in one, removed that as I'm on ethernet anyway and the slot sped back up and I can crossfire now in radeon settings, thanks!

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