Product Showcase - Interior
To the left side you can see that you'll get 8 PCI slots to play around with so in theory you can house up-to three graphics cards in here, four if you are lucky. Theres room for eight PCI-E cards of up to 316mm in length. You secure the graphics cards or other cards with a thumbscrew. At the top rear side we can see one 120mm fan, it is included and installed for you already. In the upper mesh you'll notice that mounting holes for other fan and radiator solutions have already been prepped.
A good and popular trend these days is to make a big gaping hole in the motherboard tray. This actually is a CPU back plate cutout which allows you to remove and install a new CPU cooler much easier. Typically you'd need to take out the motherboard to install a new cooler, now you can access it from both sides without that unpleasant experience of removing a motherboard from the chassis.
The photo came out pretty dark but here's the lower segment of the chassis. You can install long PSUs if needed, or alternatively you could take out the lower drive cage and install a 2nd radiator for your liquid cooling loops.
With the side panel removed we can see there's enough space on the backside to route all that cabling through. Mind you that the side panel has a indentation as well, creating some more room.