I recently built my brother a new computer, and after I completed installation of everything, and had installed the ATI Catalyst drivers, I noticed that the card was running in x8 mode in a PCIe x16 slot. I checked to make sure that I had installed the card into the correct slot for single discrete-graphics operation, and I had.
It turns out that I had been careless in reading the motherboard manual, and that it had come with a little slot filler that had to be installed when only 1 discrete graphics card is in the system.
My question is, what is the purpose of this? I have seen other systems that did not require such an accessory/whatever it is, and worked at the full speed of the slot with the card. Why did this motherboard need to include this design feature?
Motherboard on Newegg: link