Optiplex 7040 not detecting discrete gpu

Question

Kia Ora, Hello, I have recently purchased a Dell Optiplex 7040 and I want to add a discrete GPU. I consider myself to be very much a beginner when it comes to this stuff but I have attempted a great number of things and cannot get the system to even register a PCIe device. I have tried basic troubleshooting such as removing the CMOS battery, updating the BIOS, enabling legacy boot mode, and following the steps provided in this article. I have also tried swapping the slot the card uses as well as installing a network card in all of the slots to verify they work. Low and behold the network card is detected fine and drivers are automatically installed on boot. As soon as I change that to a discrete GPU the system no longer displays any device in the used PCIe slot. This is in both device manager and in BIOS. As far as I can tell in my limited capacity the BIOS or maybe the Win10 install has some setting that doesn't check for a GPU or something. I should also mention as it may pertain to this matter. The GPU is driven by an external power supply separate of the proprietary one supplied with the PC as that didn't have any 6 pins. This PSU is 500W and exclusively runs the GPU. I wasn't sure if this was the cause of the issue but the gentleman who sold me the PSU and GPU assured me it wasn't. The system specs are as follows: i5 6500 Win10 Pro 16gb Gskill Ripjaws DDR4  Radeon HD 5770 BIOS v1.8.1   Any help on this matter would be immensely appreciated.   Nga Mihi, Regards, Jacob

bradthetechnut · Answer

Hi @Godzilla090 ,

Are you sure the card isn't a Mac Edition?

If one step doesn't work put it back and then go to the next:

Try turning off Secure Boot in BIOS.
Go into Display or Video in BIOS. Try different settings such as Auto, or if it's already there, then choose the setting that's for onboard graphics first and GPU card 2nd, and so on. Try the different settings.

Optiplex Desktops

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