Product Showcase - Interior

 
You'll notice that there are two compartments residing inside the Cosmos II, obviously done for optimal airflow and thermal management. Your PSU and HDDs are separated in a (lower) compartment to the motherboard and the components. Air will be drawn in from the front based in fan intakes. As you can see the lower HDD bays have dual fans as well.  As you can see there are some things that pop out, the metal looking motherboard tray and space, lots of it. Graphics card could even be 39 CM in length. Your average high-end card is max 31 cm in length these dasy actually. The motherboard tray BTW, that's aluminum, not a metal sheet. 

At the inside top you can see plenty of clearance / space for cooling, you could house a triple-rad there for liquid cooling. Right now it houses a 120 mm black fan x 1, 1200 RPM rated at 17 dBA. You can however fit 200 mm fan x 1 / 140 mm fan x 2 or 120 mm fan x 3.
 

 
On the rear left we spot another fan, obviously the rear exhaust fan which is a 140 mm fan x 1, 1200 RPM, 19 dBA. Cooler Master uses black cabling for the fans and wiring overall. 
  

 
The usual spaghetti of cables is mostly for front panel connectivity. Cable routing is just not a problem with this chassis though. Mind you that the front-panel USB 3.0 connectors must be connected to the proprietary USB 3.0 header on the motherboard. Also the fornt side SATA dock needs wiring to the motherboard and PSU of course, hence there are quite a number of cables to deal with. 
 

10+1 PCI slots, yeah that should be plenty. Oh hey a Cooler master logo is also stamped into the motherboard tray: