[SOLVED] Disable 3400G RX Vega Graphics to free up PCIe lane?

DeltaTaco

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Apologies if this is a stupid question - I've already prepared myself for the answer to be "no".

Computer was getting a bit dated and I decided to upgrade. After looking at GPU prices at the moment I decided to keep my current graphics for the moment, I was running dual RX480s. I seem to have goofed as I can only get the PC to recognize one of the GPUs and not both (seems to be whichever is in the top slot, so not a GPU problem).

Reading the motherboard manual (MSI X470 Gaming Plus Max), it says that PCIe slot 4 is unavailable for "Ryzen with Radeon Vega Graphics and 2nd Gen AMD Ryzen with Radeon Graphics Processors". Since I have a Ryzen 5 3400G installed it looks like I fall into the first category. Also worth mentioning that PCIe slot 6 is unavailable with an M.2 drive installed in the second M.2 slot (assuming they use the same PCIe lane). From this I am guessing that the Vega graphics integrated into the CPU is utilizing PCIe lane 3 which is why the installed card is not recognized, but that's just a guess.

I also cannot use the third PCIe slot because it is PCIe 2.0 x4, which is below AMD's requirements for Crossfire. Did I shoot myself in the foot here and not do enough research, or is there a way to disable the Vega graphics so I can use my second GPU in slot 3 in Crossfire?
 
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Solution
Apologies if this is a stupid question - I've already prepared myself for the answer to be "no".

Computer was getting a bit dated and I decided to upgrade. After looking at GPU prices at the moment I decided to keep my current graphics for the moment, I was running dual RX480s. I seem to have goofed as I can only get the PC to recognize one of the GPUs and not both (seems to be whichever is in the top slot, so not a GPU problem).

Reading the motherboard manual (MSI X470 Gaming Plus Max), it says that PCIe slot 4 is unavailable for "Ryzen with Radeon Vega Graphics and 2nd Gen AMD Ryzen with Radeon Graphics Processors". Since I have a Ryzen 5 3400G installed it looks like I fall into the first category. Also worth mentioning that...

Math Geek

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you misread that. it means a ryzen cpu with built in graphics. the 3600x does not have any built in gpu.

so you do not fall into that category and it means nothing to you.

you need to focus on what happens when you populate various slots such as the second pcie slot or the m.2 slots and so on. that's the only place you need to be sure you know where the lanes are going.
 

Zerk2012

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Ambassador
Apologies if this is a stupid question - I've already prepared myself for the answer to be "no".

Computer was getting a bit dated and I decided to upgrade. After looking at GPU prices at the moment I decided to keep my current graphics for the moment, I was running dual RX480s. I seem to have goofed as I can only get the PC to recognize one of the GPUs and not both (seems to be whichever is in the top slot, so not a GPU problem).

Reading the motherboard manual (MSI X470 Gaming Plus Max), it says that PCIe slot 4 is unavailable for "Ryzen with Radeon Vega Graphics and 2nd Gen AMD Ryzen with Radeon Graphics Processors". Since I have a Ryzen 5 3400G installed it looks like I fall into the first category. Also worth mentioning that PCIe slot 6 is unavailable with an M.2 drive installed in the second M.2 slot (assuming they use the same PCIe lane). From this I am guessing that the Vega graphics integrated into the CPU is utilizing PCIe lane 3 which is why the installed card is not recognized, but that's just a guess.

I also cannot use the third PCIe slot because it is PCIe 2.0 x4, which is below AMD's requirements for Crossfire. Did I shoot myself in the foot here and not do enough research, or is there a way to disable the Vega graphics so I can use my second GPU in slot 3 in Crossfire?
The chip has limited lanes for the video card/ PCI-E lanes/ M.2 slots depending on how the M.2 slots are designed on the board some just kill SATA slots.
X4 is what is required for AMD Xfire for the green team they required X8
https://en.wikichip.org/wiki/amd/ryzen_5/3400g

When your using a video card the built in graphics should be disabled by default.

SLI / Xfire is dead anyhow
 
Solution

DeltaTaco

Distinguished
Feb 6, 2016
60
0
18,640
you misread that. it means a ryzen cpu with built in graphics. the 3600x does not have any built in gpu.

so you do not fall into that category and it means nothing to you.

you need to focus on what happens when you populate various slots such as the second pcie slot or the m.2 slots and so on. that's the only place you need to be sure you know where the lanes are going.
I apologize - I had the wrong name in the title it must not have updated to the edited processor quickly enough. I have the Ryzen 5 3400G