Cooler Master HAF Stacker 935 Modular Case Review

Cooler Master recently released its much anticipated HAF Stacker line of cases, and we’re here to introduce you to this new and innovative enthusiast level offering. We were sent the HAF Stacker 935 for review, which consists of a Mid-Tower HAF Stacker 925 and a mITX HAF Stacker 915R. Together, they appear to make for a truly unique system build opportunity that’s limited only by one’s imagination. So, let’s go ‘stacking’ and find out what this new HAF Stacker series is all about!

cm_hafstacker (1)Specifications and Features

As mentioned in the introduction, the HAF Stacker cases consist of the main mid-tower case and a couple different options for the mITX cases. Even though the main case is assigned a part number (925), it is not sold separately. It’s only included in the 935 kit. The smaller mITX 915 series cases can be bought separately and added to the 935. If you prefer, you can buy one or more 915 series mITX cases as your starting point. However, if you need support for anything other than a mITX motherboard, you’ll need to purchase the 935 kit in order to get the mid-tower sized main unit.

The HAF Stacker 915 mITX cases come in two different flavors – the 915R and 915F. The 915R has the PSU mounting at the rear, while the 915F PSU has the mounting at the front. For reference, here is a comparison of the 915R and 915F. Cooler Master claims the 915R places an emphasis on better HDD support and keeping the GPU cool, while the 915F throws its emphasis on supporting tower type CPU coolers and keeping the CPU cool.

cm_hafstacker (2)

Here are the specifications for the HAF Stacker 935 as provided by Cooler Master. The specifications for the HAF Stacker 935 mix in some of the 915R specifications, but I’ll also include the 915R specifications on their own for clarity.

Cooler Master HAF Stacker 935 Specifications w/915R Specifications
ModelHAF-935-KWN1
ColorBlack / Black
MaterialBezel: Mesh/Polymer; Case body: Steel SGCC-t0.7
Dimension235 x 719 x 578 mm / 9.25 x 28.8 x 22.75 inch
Weight15.6 kg / 34.5 lbs (Net Weight)
M/B TypeEATX, ATX, microATX, Mini-ITX (915R)
5.25″ Drive Bay3 + 1 (915R)
3.5″ Drive Bay9 (3 x modular cage)
SSD Bays9 (converted), 1 (MB tray) + 3 (915R)
I/O PanelUSB 3.0 x 2, USB x 2, Audio
Expansion Slots8 + 1 and 2 (915R)
Cooling SystemTop: 120mm x 2Front: 120mm x 2 / 92mm x 1 (included)Rear: 140mm (included) / 120mm x 1Side: 120mm x 6, 140mm x 4 (915R)Radiators: 360mm x 2 / 280mm x 2 (Side); 140mm / 120mm x 1 (Rear
Power SupplyStandard ATX PS2 x 2
Rear / Bottom Mounted
Maximum CompatibilityVGA card length: 354mm / 13.9 inch; 360mm / 14.17 inchCPU cooler height: 180mm / 7 inch; 80mm / 3.15 inch
Warranty2 years
UPC Code884102025228

…And the standalone 915R specifications. Of note here is that the front I/O panel does not exist on the 915R that’s included with this kit. However, if a 915R is bought separately, it will come with the front I/O panel.

HAF Stacker 915R Specifications
ModelHAF-915R-KKN1
ColorBlack / Black
MaterialBezel: Mesh/Polymer; Case body: Steel SGCC-t0.7
Dimension228 x 248 x 578mm / 8.97 x 9.76 x 22.75 in.
Weight5.5 kg / 12.12 lbs (net weight)
M/B TypeMini-ITX
5.25″ Drive Bay1
3.5″ Drive Bay3 (1 x modular cage)
SSD Bays3 (converted)
I/O PanelUSB 3.0 x 2 (No reset button) / Audio
Expansion Slots2
Cooling System(varies by stacking setup)Front: 92mm x 1 (included)Side: 6 x 120mm or 4 x 140mmRadiators: 360mm x 2 / 280mm x 2 (Side)
Power SupplyStandard ATX PSU
Rear / Top Mounted
Maximum CompatibilityVGA card length: 360mm / 14.17 inchCPU cooler height: 80mm / 3.15 inch
Warranty2 years
UPC Code884102025259

The below features and descriptions are provided by the Cooler Master website.

HAF Stacker 935 Features

  • World’s first “mod-tower” with stacking functionality for limitless utility
  • Stack extra 915F or 915R for dual/triple system or additional water cooling and storage
  • Dust filtered intakes and sliding filter frames
  • Intuitive design for flexible and easy installations
  • Greater storage expandability with transferrable drive cages between chassis
  • Full window version (tinted)
  • Modular I/O functionality for future-proof connectivity
  • Multiple removable dust filters (top, front, bottom, side panel) for improved system maintenance

HAF Stacker 915R Features

  • First expandable m-ITX chassis; modular design compatible with HAF Stacker system
  • Stack extra 915F or 915R for dual/triple system or additional water cooling and storage
  • M-ITX Chassis supporting long graphics card, standard PSU (front mount) and water cooling
  • Intuitive design for flexible and easy installations
  • Greater storage expandability with optional drive bay accessories
  • Front 92mm fan offers direct storage cooling

The images below are also courtesy of Cooler Master. As you look through the pictures, you’ll get a good feel for many of the available features and build opportunities.. We’ll get into more detail of all this as the review progresses. First, the HAF Stacker 935 features.

cm_hafstacker (6)
cm_hafstacker (3)
cm_hafstacker (4)
cm_hafstacker (4)

… And the feature pictures for the HAF Stacker 915R.

cm_hafstacker (7)
cm_hafstacker (8)
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Are you beginning to get a feel for the many options available with the Stacker system? I’m liking what I see so far, so let’s get the box up on a table and have a look!

Packaging and First Look

A relatively plain brown cardboard box is used to house the HAF Stacker 935. Simple branding is applied to the front, back, and sides. Inside, you’ll find the HAF Stacker well protected with the customary Styrofoam blocks with both cases wrapped in a foam type bag.

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With the HAF Stacker 935 unwrapped, we get our first look at the two chassis that make it up. A plastic film is applied to the side window for further protection during transportation. There is an enclosed leaflet that explains how to join the two cases.

HAF Stacker 935 - First Look
HAF Stacker 935 – First Look

HAF Stacker 935 First Look
HAF Stacker 935 First Look

Secured inside the main unit is a box with the accessories. There are two cover plates used to block the PSU and I/O openings with the idea being the 915R upper unit will be used as a storage area for the main system (think additional HDDs, radiators, etc.). Also included is a SATA power extension cable and a bag of miscellaneous screws and zip-ties.

Bundled Accessories
Bundled Accessories

As long as we’re on the topic of accessories, one of the cool things about the HAF Stacker line is Cooler Master’s intent to offer a wide array of accessories through their online store. Below is a list of the items that will be available initially, but I’m sure more will be added down the road.

Available Accessories
Available Accessories

Exterior Tour

Main Unit

Beginning with the main unit, the left side panel is decked out with a large smoke colored window. The right side panel is void of any distinguishable designs and is simply a solid black panel.

Smoke Colored Window
Smoke Colored Window

Solid Panel
Solid Panel

The front of the main unit has three 5.25″ bay covers that match the overall mesh design of the front bezel area. At the top is the front panel I/O connection area. Here we have two USB 3.0 ports, two USB 2.0 ports, headphone and MIC jacks, and the power button. There is no reset button or HDD activity LED.

Front Panel
Front Panel

Front Panel I/O Area
Front Panel I/O Area

The top panel that comes installed on the 915R can be removed and installed on the main unit as well. If you decide to put the 915R on the bottom and stack the main unit on top, you’ll need to do this. Here is a picture of the top panel installed on the main unit.

Top Panel on Main Unit
Top Panel on Main Unit

Looking at the back of the main unit, we see a bottom mount PSU opening, eight ventilated expansion slot covers, and a vertically positioned expansion slot cover. The upper half consists of the exhaust fan opening, the I/O shield opening, and three rubber protected pass through holes. The two larger holes will accept tubing up to 1″ in diameter, and the small hole will accept tubing up to 3/4″.

Main Unit Back Area
Main Unit Back Area

The bottom of the main unit has a removable dust filter for the PSU mounting area and two large pass through holes. As expected, the rails that make up the feet can be removed and transferred to the 915R. The four rubber strips on the rails are a nice touch as well.

Bottom of Main Unit
Bottom of Main Unit

Bottom Slide Out Filter
Bottom Slide Out Filter

The main unit is a pretty sharp looking mid-tower case in its own right. So far, so good on the exterior, let’s check out the companion 915R.

915R

Each side panel on the 915R is drilled to accept many different cooling options. Fan support includes three 120 mm fans per panel or two 140 mm fans per panel. Each panel can also hold a 360 mm or 280 mm radiator. I can’t help but think what an awesome radiator box the 915R would make. But, that’s just one of many potential uses.

Left Side Panel
Left Side Panel

Right Side Panel
Right Side Panel

The next picture is of the mesh top panel re-installed on the 915R.

Top Panel on 915R
Top Panel on 915R

The back of the 915R has two ventilated expansion slot covers and a top mount PSU opening. At the bottom is where a motherboard’s I/O shield gets installed. Keep in mind though, the 935 kit in its delivered state is not conducive to building a second system in the 915R. This is why the accessory pack has plates to block off the PSU and I/O shield openings.

The bottom has five pass through holes, one of which is rather large. The large one is designed for the pump/block assembly of an All-in-One cooler to fit through. This will allow you to install the radiator portion of the AIO cooler in the 915R and route the pump/block assembly to the motherboard. The smaller holes can be used to pass just about anything between the two cases: tubing, cables, or whatever you decide.

915R Back
915R Back

915R Bottom
915R Bottom

The front panel of the 915R is another example of why a dual computer setup is not possible… there is no front I/O panel. As I mentioned earlier, purchasing the 915R separately will get you a version with the front I/O panel. I would really like to see a complete 915R included in the 935 kit, which would offer the user even more out-of-box options. The cost would increase in doing so, but I think it would be well justified. That being said, I assume the parts needed to convert it to a complete 915R will be available soon.

915R Front Panel
915R Front Panel

Interior Tour

Main Unit

Beginning with the main unit, let’s have a look inside the two cases that make up the HAF Stacker 935. The all black interior features lots of cable routing holes, two removable HDD cages, and a huge CPU cooler access hole. At the bottom, there are two large pass through holes to integrate hardware between the main unit and a companion case below it. The power supply mounting area has four rubber pads for the PSU to set on and a ventilation area to provide the PSU with proper airflow. Along the back, you can see the eight ventilated expansion slot covers and the included 140 mm exhaust fan. The expansion slot covers are held in place with thumbscrews.

cm_hafstacker (32)
Interior Look

CPU Cooler Access Hole
CPU Cooler Access Hole

Bottom Area
Bottom Area

Rear Area
Rear Area

Under the top deck, we have accommodations for three 120 mm or two 140 mm fans. Naturally, if you stack a 915 on top, it won’t make much sense to install fans here. However, if you decide to put a 915 at the bottom, then have at it. In what I consider to be a missed opportunity, there isn’t enough room for a radiator with fans under the top deck. If you’re willing to sacrifice the HDD cages, a 240 mm radiator can be installed up front. So, all is not lost if you need to install a radiator in the main unit. In all reality, water cooling hardware is meant to be installed in the 915R… and it’s the perfect place for it.

Under Top Deck
Under Top Deck

Moving around to the drive bay area, we first come to the three 5.25″ drive bays. Drives are secured with a locking latch that has a lever built into it. Just move the lever one way or the other to install/remove a device. The 3.5″ drive cages are modular, can be completely removed, or used in any combination desired. You can use just the bottom one, just the top one, or both. You can even remove the bracket located at the very bottom of the cages if even more room is needed.

5.25" Drive Bays
5.25″ Drive Bays

3.5" Drive Cages
3.5″ Drive Cages

HHD Cages and Bracket Removed
HHD Cages and Bracket Removed

With the front panel off the main unit, we see where two optional 120 mm fans can be installed right behind the front bezel. The second picture below gives you a good look at the inside area of the 5.25″ drive bays.

Front Intake Fan Mounting Area
Front Intake Fan Mounting Area

5.25" Drive Bays
5.25″ Drive Bays

Turning the main unit around, we can inspect the area behind the motherboard tray. A provision has been made to install a 2.5″ HDD or SSD just below the CPU cooler access hole. Nice addition there! The room between the motherboard tray and the side panel is a bit tight and measures right at 11/16″. That’s not the most room I’ve ever seen allotted here; but with proper cable management, it should be doable.

Behind the Motherboard Tray
Behind the Motherboard Tray

2.5" HDD or SSD Mount
2.5″ HDD or SSD Mount

Tale of the Tape
Tale of the Tape

The case wiring is very simplistic, and just the basics were implemented. Cooler Master says they left out the reset and HDD activity wiring to help with cable management. They go on to say the power switch can basically provide the same function as a reset switch on modern systems, and I agree with them. I can deal with the reset switch missing, but a HDD activity light is nice to have. Most modern systems don’t use the AC97 front panel header either, so I’m not sure why they included that as part of the audio cable.

USB 2.0 and Audio Cables
USB 2.0 and Audio Cables

USB 3.0 and Power Cables
USB 3.0 and Power Cables

915R

The interior of the 915R companion case, as it’s offered in the 935 kit, presents many different usage options. Whatever you decide to use the 915R for, it will be be extremely well ventilated as both side panels are almost completely meshed. There is also a screen type filter applied to each panel for dust control. With the side panels off, you can see how open the 915R is. If you need even more room, the HDD cage and 5.25″ bay are both removable. The HDD cage will accept three drives, and there is one 5.25″ bay available. The 5.25″ bay uses the same retention mechanism as the main unit.

Side Panel and Filter
Side Panel and Filter

Both Panels Removed
Both Panels Removed

HDD Cage Removed
HDD Cage Removed

HDD Cage and 5.25" Bay Removed
HDD Cage and 5.25″ Bay Removed

HDD Cage and 5.25" Bay
HDD Cage and 5.25″ Bay

Just to give you an idea of one way the 915R can be used, you can relocate the HDD cages from the main unit and install them in the 915R. That should be plenty of HDD storage capacity, don’t you think?

915R with all the Cages
915R with all the Cages Installed

At the back of the 915R, we can see the two ventilated expansion slot covers and get another look at the PSU and motherboard’s I/O shield opening. The 915R will accept mITX motherboards only; but as I explained earlier, you’ll need to procure additional parts to build a separate system in it. With the front bezel removed, we can see the included 92 mm intake fan. The last picture below is an inside view of the same front intake fan.

Rear Area - 915R
Rear Area – 915R

Front Intake Fan
Front 92 mm Intake Fan

Front Area and 92 mm Fan
Front Area and 92 mm Fan

Putting it all Together

System Specs

For this build, I’m going to mount the 915R up top and use it as storage for the Swiftech H220 radiator and fans. Keep in mind, this is just one of many ways to assemble a system in the 935 kit.

Assembly began with the main unit. First, I installed the optical drive in the middle 5.25″ drive bay, mounted the motherboard, and installed the PSU.

DVD Drive Installed
DVD Drive Installed

Motherboard Installed
Motherboard Installed

PSU Installed
PSU Installed

Next up was installation of the HDDs. The HDD trays expand by releasing a latch on the bottom side of them. Once expanded, you simply set a drive in the tray and close it. All the trays will accept 3.5″ and 2.5″ drives.

HDD Tray and 3.5" Drive
HDD Tray and 3.5″ Drive

HDD Tray Expanded
HDD Tray Expanded

HDD Tray Closed
HDD Tray Closed

HDD and SSD Installed
HDD and SSD Installed

Next, I installed the video card and began the process of wiring everything else up. Once that was complete, a few well placed zip-ties were needed to organize the wires behind the motherboard tray. The right side panel easily fit once that task was complete.

Video Card Installed
Video Card Installed

Wiring Complete
Wiring Complete

Tome for Some Organization
Tome for Some Organization

Right Side Panel Installed
Right Side Panel Installed

Here are a couple additional pictures of the completed main unit.

Completed Main Unit
Completed Main Unit

Completed Main Unit
Completed Main Unit

Turning our attention to the 915R, we first need to mount it at the top. The bottom rail of the 915R interlocks with the top rail on the main unit. All you have to do is set the 915R a little offset towards the rear, and then just slide it forward. Once that is done, you secure the two cases together with two screws on each side. If you need to install the 915R at the bottom, then you’ll need to remove the feet from the main unit and install them on the bottom of the 915R. At that point, the main unit will attach to the top of the 915R in the same manner described above.

915R Ready to Slide Forward
915R Ready to Slide Forward

915R in Position
915R in Position

915R Mounted on Top
915R Mounted on Top

The next step was to install the H220’s radiator and fans to the left side panel. Once that was completed, the panel was reinstalled. As you can see in the second picture below, there is plenty of room to leave both the 5.25″ and 3.5″ cages in. So, in the configuration I chose to build you can install up to nine 3.5″ drives and four 5.25″ drives. And, don’t forget the extra 2.5″ drive location behind the motherboard tray! You could even add another radiator (240 or 280 mm) on the opposite side panel if you wanted and still leave the cages in. If you remove the two drive cages… err… we could literally go on forever here with all the available options. Like I mentioned in the introduction, you’re only limited by your imagination.

Radiator and Fans on Side Panel
Radiator and Fans on Side Panel

Side Panel Installed
Side Panel Installed

All that’s left is to button things up and enjoy the view of a completed system. Putting the system together was actually a breeze to complete, and the cable management system worked very well. Below is a series of pictures showing the completed build, enjoy!

HAF Stacker 935 Completed Build
HAF Stacker 935 Completed Build

HAF Stacker 935 Completed Build
HAF Stacker 935 Completed Build

HAF Stacker 935 Completed Build
HAF Stacker 935 Completed Build

HAF Stacker 935 Completed Build
HAF Stacker 935 Completed Build

HAF Stacker 935 Completed Build
HAF Stacker 935 Completed Build

HAF Stacker 935 Completed Build
HAF Stacker 935 Completed Build

HAF Stacker 935 Completed Build
HAF Stacker 935 Completed Build

HAF Stacker 935 Completed Build
HAF Stacker 935 Completed Build

Conclusion

The HAF Stacker 935 is listed for $169.99 at Newegg, but isn’t quite available yet. Given the multitude of options this kit offers and its unique dual case design, I think the price is very reasonable. The ability to add companion cases as your needs change is a great option to have. This truly is a system that can grow with you and will follow you through future upgrades.

Putting together the system I chose to build was very easy to accomplish. There is plenty of room to navigate inside both the main unit and the 915R, and the cable management system worked flawless. The most difficult part of putting a system together is actually deciding how you want to do it. With so many options at your disposal, it’s worth taking a few minutes to plot things out for the equipment you’re going to install. What a great problem to have, right?

About the only gripe I have with the HAF Stacker 935 is that the 915R companion case doesn’t offer the ability to build a second system in its out-of-box form. If they would package a full fledged 915R, or at least the front I/O panel for it, that would give the customer a slew of additional options. Luckily, the parts needed to accomplish this should be available to purchase separately.

If you’re like me and enjoy having a ton of options when assembling a system, then you need to take a good look at the HAF Stacker 935. Bring your imagination with you… you’ll need it!

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Dino DeCesari (Lvcoyote)

About Dino DeCesari 230 Articles
Dino DeCesari was a pillar of the Overclockers.com community for over 13 years when he passed away suddenly in 2015. His legacy lives on through his hundreds of computer hardware reviews posted here. Dino spent time in the army as a Telecommunication Center Specialist and received a commendation medal. He had a successful 20+ year career in the automotive parts and technology industry, where he eventually bought and sold his own business. Once retired, he volunteered as tech support for a non-profit and his local school district. 

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Avatar of bassnut
bassnut

Premium Member

2,532 messages 14 likes

Nice and really gives me room for thought. I'm not sure if this will directly compete with the 900D but is looks like it might come very close and at half the cost. I'll be keeping an eye out for this to get an up close look see for sure.

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kamran

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