The HAF Stacker is such an interesting case that I have been sitting here debating on what the best way to approach covering the exterior section. The reason things get a little tricky is because officially the HAF Stacker consists of three different cases but there is a lot of overlap between them. I have split my outside section into subsections based on each case.
To start things off we have the HAF Stacker 915F. This is one of the two short Mini-ITX cases. The main thing to remember between the 915F and the 915R is the letter represents where the power supply can be mounted. On the 915F the power supply mounts at the front of the case. The front of the 915F has the same industrial mesh design as the other two cases and like the other HAF series cases. Really short of looking at the back of the case the only thing that stands out from the 915R that is included with the 935 is the front I/O panel. You get a power button, microphone and headphone ports, and two USB 3.0 connections. Everything you might need. On the both side panels of the 915F Cooler Master has vented all the way across in a design that should allow you to install three 120mm fans each or two 140mm fans.
The tops of all of the HAF Stackers are almost completely made out of mesh with it covering everything except a 1-inch ring around the top. I will get into how the cases lock together when I cover the other cases later in this section.
Around back, as I mentioned before, the 915F does not have a power supply mount showing on the exterior. You do however still get a 120mm fan, the rear I/O, and two PCI slots. In order for the internally mounted power supply to get power you do still have a power connection just above the PCI slots.
The bottom of each of the HAF Stackers is similar to the pictures below. In order for you to be able to use multiple cases for one build, Cooler Master has included multiple holes in the bottom of the case to pass cabling or water cooling tubing through. The hole on the left side is the largest but the four holes without grommets give you other options as well. We can also see that the 915F has a filtered intake on the right side for the internally mounted power supply. For feet we have two tracks that are removable for when you lock the cases together. Each track has two long rubber feet on them to give each case more than enough traction to stay in place.
As I mentioned before, on the exterior there are only a few differences between the 915R and the 915F. As you can see below, the 915R that comes with the 935 does not have a front I/O panel. If you buy the 915R on its own it does come with a front I/O panel though. You still get the same industrial styling and blacked out Cooler Master logo in the front mesh.
Around on the back of the 915R we have the same rear I/O panel and two PCI slots but in place of the rear mounted fan we have the rear mounted power supply up above your motherboard.
So by now you have to be wondering more about how these cases stack together. Both the top and bottom of each case have a locking system. The feet and top panel attach to the cases in the same way. Up top, you have four screws holding everything together, once you remove them you can slide the top panel off and (assuming you have removed the feet from your other case) you can slide the two cases together. Once they are together putting the four screws in locks everything in place. As you can see in the picture below, when you have the top panel removed, you have full access to the inside of the case other than that single support bar across the top. Combined with the multiple holes in the bottom of the cases, you can route your cables and/or water-cooling in any way you are feeling at the time.
The 935 is over twice the size as the 915’s and would fall into what I would consider a large mid tower in overall size. The industrial design matches the front of the 915’s but with three 5.25-inch bays it has more going on. You have the same dual USB 3.0 ports as well as microphone and headphone ports. You also have a small plastic power button on the 935 as well, just like on the 915’s. Beyond the size, the other main difference between the 935 and the smaller 915’s is the inclusion of a large side panel window. The side panel window is a little different than normal. Cooler Master added a little extra style by having it “buldge” out slightly. The window is also nearly the entire side of the case. Normally this doesn’t look good because it doesn’t give you any room to high your cabling but the tinting in the side panel mutes things slightly.
The right side of the 935 has nothing at all going on though.
Just like with the 915’s you have a very large opening on the top of the case to give you options when stacking cases together. The 935 isn’t as open as the 915’s though. Cooler Master did make sure to give you multiple options for fan mounting points up top, it also looks like you can fit a 360mm radiator, assuming there is room above the motherboard.
Around on the back things are a lot different than with the 915’s. For starters we have a power supply mount down at the bottom. For PCI slots you get an 8+1 configuration. That means the 935 has 8 actual PCI slots and Cooler Master slipped a 9th up above the others for installing something small like an extra USB expansion or a slot mounted fan speed controller. As if the HAF Stacker didn’t gig you enough options for water cooling, the back of the 935 does have three grommeted holes just in case you decide to do external water cooling. Just above the rear I/O the also slipped in a 140mm exhaust fan. There are mounting holes for a 120 should you already have a 120mm radiator or an R9 295X2 with its 120mm radiator and fan.
Now that you know a little about all three of the cases, I wanted to show off a few of the possible combinations that the modular case design allows. As a Mini-ITX build fan the combination that really stood out for me was the possibility of combining multiple 915’s (R or F’s) into a stack. I had a few ideas of where this might come in handy, but I’m sure you might be able to come up with a few on your own as well. One example of a use for this would be as his and hers LAN rigs. As someone who goes to events with my wife as often as I can, being able to stack our two PC’s together would make bring them into a LAN easier as well as take up less room on our table. Another similar use would be when you have multiple computers in the same office, like when you have a family of gamers. Stacking would save space and could sit perfectly in between two desks. The third idea I had for this combination was an in house stack of Mini-ITX servers. You could build one as a NAS or a file server and expand out with one as a game server. You could really stack as high as you wanted depending on your needs.
Adding in the larger 935 into the mix makes things even more interesting. You can build a full sized PC and use one of the 915’s as a second PC or as expansion room for more water-cooling or additional hard drive capacity.