I mounted a full size ATX motherboard without problems into the Armor Jr. but found some of the larger after-market CPU heatsink fans might interfere with the rear case fan. If that becomes an issue, the rear 120mm fan can be easily remounted on the outside of the enclosure (I have been doing this for years with many of my custom builds). The motherboard and expansion cards lined up nicely in their respective openings.
The power supply mounting position remains the same for both ATX and BTX installations. Even Thermaltake’s new flagship Toughpower 750 watt power supply fit right into the space provided. (Watch for our review of the Toughpower 750W in the near future 🙂
Up to four HDDs can be mounted into the internal 3.5′ drive cage, which uses rubber grommets to mount ead HDD and help reduce vibration noise. When mounted in the lower ATX position, the drives are positioned sideways directly behind the front case fan.
Mounting the drive cage in the upper BTX position, orients the drives front-to-back and allows using an optional 120mm cooling fan.