This model may not allow you to use iGPU when it detects dGPU. BIOS has no option for multi display. Do you see the following in bios > System Configuration   not sure if you can disable PCIe slot with this.  It says PCI and not PCIe so not sure.  9010 mt mobo has one pci.  So this control may turn off pci only.
got my new refurbished video card in my Optiplex 9010 MT working, but at the moment I dont got a Display Port for the card, can I some how use integrated graphics with the video card? windows 10 auto sets it to the video card i don't have the port for.   yes i got a dp to hdmi converter already on the way but video card came faster than expected 
integrated graphics with dedicated graphics card?