MSI Radeon RX 550 PCI-E Bus Width problems with Dell OptiPlex 755

[oldduck12345]

I have a bit of a problem. I have an old Dell OptiPlex 755 MT that I've been using for a while. I recently added the MSI Radeon RX 550 ITX Aero graphics card into it. I had to remove the bracket from the GPU, and secure it using some more unconventional means, however it now resides in the computer with no problem. Unfortunately, the card is UEFI only, and this old Dell motherboard only supports Legacy. Whenever I want to change bios settings, I have to switch to the integrated GPU. Not a big problem for me, just a bit of a pain. xD

Anyways, just wanted to describe the situation before I got to my problem. I wanted to do some light gaming on this rig, but the PCI-E slot settings are not working right. I uploaded a screenshot. I've tried everything from reseating the card, changing drivers, even registry edits, and I have not been able to fix this issue. I know that this is most likely a motherboard issue, however I can't change my motherboard at the moment. Thank you for any and all assistance.

 

[oldduck12345]

Oh, specifically, the Bus Interface settings. It's supposed to be running at PCI-E x8 3.0, however it's only running at x1 1.1. I tried using the render test (the little question mark thingy), and it didn't change.

 

[RCFProd]

As you've said, it seems to be an issue related to the software of the motherboard. I'm not sure if anything can really be done about that.

 

[RCFProd]

Read the following interesting post made by user SpeedStep in the following link:

Dell Community thread

 

[helpstar]

So you did plug it into the PCIe x1 Slot (picture number 16) or into the PCIe x16 Slot (picture number 15)?
http://en.community.dell.com/cfs-file/__key/communityserver-discussions-components-files/3514/755-MT----Optiplex.jpg

uninstall all previously installed graphics drivers with ddu uninstaller and reinstall the amd driver

update the motherboard´s BIOS
http://www.dell.com/support/home/en/us/debsdt1/Drivers/DriversDetails?driverId=2DWTY

 

[oldduck12345]

So you did plug it into the PCIe x1 Slot (picture number 16) or into the PCIe x16 Slot (picture number 15)?
http://en.community.dell.com/cfs-file/__key/communityserver-discussions-components-files/3514/755-MT----Optiplex.jpg

uninstall all previously installed graphics drivers with ddu uninstaller and reinstall the amd driver

update the motherboard´s BIOS
http://www.dell.com/support/home/en/us/debsdt1/Drivers/DriversDetails?driverId=2DWTY

Well, this motherboard only has once PCI-E slot, and it says that it is PCI-E x16. Also, I already tired reinstalling the drivers, with no luck. I am also already running Dell A22 bios, but I'll try to update it again anyways, just to be sure.

 

[oldduck12345]

So you did plug it into the PCIe x1 Slot (picture number 16) or into the PCIe x16 Slot (picture number 15)?
http://en.community.dell.com/cfs-file/__key/communityserver-discussions-components-files/3514/755-MT----Optiplex.jpg

uninstall all previously installed graphics drivers with ddu uninstaller and reinstall the amd driver

update the motherboard´s BIOS
http://www.dell.com/support/home/en/us/debsdt1/Drivers/DriversDetails?driverId=2DWTY

Okay, I just updated the motherboard's BIOS, using the link you sent. It updated, but it didn't fix my issue. Anyone have any other ideas?

 

[oldduck12345]

Would this motherboard work to solve this issue? https://www.newegg.com/Product/Product.aspx?Item=9SIAAMF4UB1396&cm_re=lga775_motherboard-_-9SIAAMF4UB1396-_-Product

 

[helpstar]

Looks like the x8 of the video card is the problem. The chipset can just run at x1 or x16 and not at x4 nor x8. But the video card wanna run at x8 and therfore the chipset sets it to x1.

Don´t get a motherboard with the same chipset. Try a gtx750 ti or other real x16 card

 

[rdguierrez]

i have a problem, i have the same Dell 755 and same RX 550, but in Device Manager gives me an 43 error with the drivers, I CANT INSTALL IT!!! i try in Windows 7 and nothing, now in Windows 10 but gives me an 43 error in Device Manager

 

[helpstar]

try a BIOS update from Dell for your 755
http://www.dell.com/support/home/us/en/19/product-support/product/optiplex-755/drivers

Which from factor is it? Maybe the power supply is insufficient.
http://www.dell.com/corp/Desktops/optix_755/pd.aspx?refid=optix_755&s=corp

Is the card working in another system?

Reset the BIOS of your Dell by jumper (ClrCMOS). Have a look in the manual how to.

The monitor is plugged into the RX550 and not the onboard graphics of the Dell motherboard?

Eventually you will have to disable the onboard graphics/ integrated graphics (IGP) in BIOS to run the RX550 correctly.

Did you try to install the drivers from AMD.com for the RX550?