Lifting away the side panel of the HAF XM in one deft motion, we uncover a very simple, yet highly functional space. Gone are the cumbersome ducts and VGA retention bracket found in big brother HAF X. There's room for six 3.5" or 2.5" drives (eight if you include the hot swap bays), a standard ATX PS2/EPS power supply, an E-ATX sized motherboard, graphics cards up to 354mm in length (463mm without HDD cage), and nine PCI slots worth of expansion. Support for CPU coolers up to 196mm in height means that the HAF XM can house Cooler Master's new TPC 812 vertical vapor chamber cooler. A 215mm by 140mm CPU cutout ensures compatibility across the board (pun intended), and six cable routing slots allow you to organize your rig just the way you like it. The larger cutouts are fitted with sturdy rubber grommets that feel built to stand the test of time and whatever cables you throw at them. Also present is the beloved PSU cable partition borrowed from the HAF X. This is a godsend for those who have a non-modular power supply and want to keep their rig looking sharp. Just slide the partition into place, fasten two screws, and watch the rat's nest vanish.
The XM wouldn't be a member of the HAF (High Air Flow) series if it didn't have the fans to prove it. With room for a total of four 200mm fans, the HAF XM is well-endowed when it comes to cooling expandability. Included with the case are two Megaflow 200mm fans mounted front and topside, in addition to a rear mounted 140mm Silent Fan. There is also room for dual 120mm or a 120mm and 140mm pairing of radiators up top to facilitate your dreams of a water-cooled system in a mid tower chassis. Users who want to grant their components the gift of unobstructed airflow can remove one side of the drive cage to open things up a bit. Speaking of drives, it is obvious that the HAF XM was designed during the SSD uprising as every 3.5" bay is compatible with 2.5" devices. There is even a secret 2.5" mount on the back of the motherboard tray. The tool-free drive trays on the HAF XM come equipped with rubber inserts to dampen HDD vibration. Compared to the HAF X, the XM uses Cooler Master's latch-locking tool-free 5.25" drive retainers as opposed to a push and release locking system. This is the only part of this entire chassis that has us even mildly concerned over durability. However, these retainers are molded from very sturdy plastic and shouldn't present an issue as long as they are not yanked out of place.
When your case has several 200mm fans pulling in vast quantities of air, there are bound to be a number of fine particles that come along for the ride. No need to worry though, as Cooler Master has installed a great set of filters in this case to keep dust at bay. When you do finally decide to clean the inside of your rig, it is very easy to detach these filters and give them a wipedown. Unlike some manufacturers, Cooler Master hasn't pampered us with a sliding external PSU filter, opting instead to have the filter clip onto the bottom of the chassis from the inside. The large 200mm fans allow for low-RPM operation, which ultimately means you'll be able to move a lot of air with much lower noise than with smaller fans.
There isn't much to see on the other side of the motherboard tray besides the already mentioned hard mount for 2.5" a drive, cable grommets, and a handful of tie-offs. If you're concerned about space for cables, don't be. There's a full 0.5" behind the motherboard tray (the side panel hump adds an additional 0.5") and 1.5" behind the drive cages to work with. After looking at it from all sides, we can tell you that the interior of the HAF-XM is very versatile and very airy. We are thrilled to see that all of the best aspects of the HAF-X's interior have been carried over, which made building in this case an absolute breeze.