Make a good thing bigger, why not? NZXT’s H9 Flow RGB scales up the stunning design of last year’s H6 Flow into a full tower PC case. Outfitted with three front ARGB-compatible fans and built from rigid steel, the $209.99 H9 Flow RGB adds support for motherboards with backward-facing connectors and delivers that same design excitement, with an angled front face and a dual-chamber interior. Our main quibbles were with the fans—fan buzz and a lack of more fan filtration are two things to contend with—but experienced PC builders will find workarounds. For less out-of-the-box hassle, users with MSI Project Zero or Asus BTF motherboards might opt for the practicality of more traditional, and budget-friendlier, cases like the Asus TUF Gaming GT302 ARGB or the even-cheaper Corsair Frame 4000D RS ARGB. But this chassis could be the ultimate mainstream case for cable-hiding showoffs.

Design: Angling for Airflow and Cable Concealment

NZXT offers the H9 Flow in three versions. The first is a $169.99 base model (no “RGB”) with three ordinary fans up front and one in the rear. Our $209.99 RGB test model comes with three RGB-equipped fans up front, but uniquely encased in one combined fan “unit” (more about which later) that NZXT calls its RGB Core Single Frame design; the rear fan is a single RGB spinner. Last, a top-end RGB Plus model ($289.99) includes a second RGB Core Single Frame triple-fan unit on the case bottom.

Traditional front-fan cases have the advantage of blowing air directly onto the components that those fans are intended to keep cool, but side-radiator cases (like Lian Li's O11 Vision Compact) offer better views of internal components for showcase-PC builders. Seen previously on models like NZXT’s own H6 Flow and the more recent APNX V1, angled fan mounts like those on the H9 Flow RGB offer the best of both worlds. All three cases also share a dual-chamber design, in which the case is wide enough to fit the power supply mounting area behind the motherboard tray. That, in turn, moves the angled fan mount far enough to the right to give onlookers a straight view from the case’s front window to the front edge of the motherboard. The H9 Flow RGB is merely the first such case we know of to support the rear-facing connectors of MSI’s Project Zero and Asus’ BTF -style motherboards.

NZXT seems to think that you’ll want the H9 Flow RGB on your desk, as its headset (headphone/microphone combo) jack, USB 3.x Type-C and dual Type-A ports and power button are all lined up along the bottom, too far down for floor-tower users to reach. The power button has a clear ring that lights to indicate when the system is powered up.

(Credit: Thomas Soderstrom)

A raised floor behind all these features provides a 25mm-deep hole into which users can flush-mount up to three 140mm cooling fans.

The bottom panel’s fan mount, mentioned above, is covered from beneath by a filter that slides out, as shown below. From this angle, we can also get a good view of the recessed fan mount’s hidden cable passages, as well as those that feed the lower edge of standard and rear-facing motherboard connectors.

(Credit: Thomas Soderstrom)

From the back we can see that the H9 Flow RGB’s power supply mount hides directly behind the motherboard’s I/O panel. The case has ATX’s standard number of expansion slots (seven), and the slot panel is boxed into the case rather than sticking out the back. Above the slot panel. the exhaust fan is mounted to long slots that allow for more than 40mm of vertical adjustment.

(Credit: Thomas Soderstrom)

We also see below how generous the space is above and below the motherboard, as the H9 Flow RGB is designed to hold thick radiator and fan combinations in both locations. The H9 Flow RGB has room for a group of slightly oversize enthusiast-class motherboards that are too large to call ATX (such as the ASRock X870E Taichi Lite), but the mounting area lacks mechanical support for the 13-inch depth of full-spec Extended ATX (EATX) boards. Boxed-in sections designed to partially hide the upper and lower cables of standard boards are functional for most boards up to 10.9 inches deep, but the forward cable passage for such boards must be opened up by removing a filler panel.

(Credit: Thomas Soderstrom)

A closer look from the other side of the boxed-in section north of the motherboard area shows two large cable passages. These allow cables like the ATX12V/EPS12V and fan connectors to reach the motherboard’s top edge. We also see a narrower slot just below the upper fan mount, which is a convenient, out-of-sight place to route the fan cables of any top-mounted radiator combo.

(Credit: Thomas Soderstrom)

Lowering our view angle lets us focus on things like the swinging/removable four-drive 2.5-inch tray, the power supply tray, and the removable dual 3.5-inch drive cage.

(Credit: Thomas Soderstrom)

Extra holes on the opposite sides of the removable 3.5-inch cage allow it to optionally fit 2.5-inch drives.

(Credit: Thomas Soderstrom)

Also compatible with the case’s top or bottom mount, the 140mm-by-420mm triple front fan is the H9 Flow RGB’s most unusual feature. The three fans are a one-piece unit, and a single black connector breaks out into NZXT RGB, standard ARGB, and PWM fan connections via an included adapter. It makes for a super-clean, neat look.

(Credit: Thomas Soderstrom)

Building With the NZXT H9 Flow RGB

The H9 Flow RGB’s installation kit includes an installation guide, and lots of screws and screw-adjacent stuff: separately sealed packs of #6-32 panhead, M3 panhead, and #6-32 combo head (power supply) screws, a spare motherboard standoff, and a #2 Phillips-to-standoff-hex adapter socket. You also get a pack of screws with special threads for engaging the holes of plastic fan frames, a pack of short zip ties, three hook-and-loop cable ties, and a cable-hole plug.

(Credit: Thomas Soderstrom)

Your mounted motherboard connects to the case via a one-piece (9-hole) front-panel button/indicator-LED cable, the usual HD Audio header for the headset combo jack, a 19-pin USB 3.2 Gen 1 header for the Type-A port, a Type-E USB 3.2 Gen 2x2 cable for the Type-C port, and the previously mentioned ARGB/PWM breakout cable for the case’s 140mm-by-420mm triple-blade fan.

(Credit: Thomas Soderstrom)

We’d love to congratulate anyone for remembering what we said about removing a filler panel for the front cables of standard-connection motherboards; the hole that opens up will be even more visible in the next image. This one primarily shows how much of the case’s internal space it required to hold our full ATX test hardware, and how much empty space remains for things like even bigger graphics cards and cooling kits than we used in our sample build.

(Credit: Thomas Soderstrom)

Though the case looks great with our hardware, we now realize that it might have looked even better had we used the included mini panel to fill a portion of the front-panel passage that we had to open up to route our ATX power, front-panel USB, and 12VHPWR cables. But it's still a very neat look, even without a reverse-connector motherboard.

(Credit: Thomas Soderstrom)

Performance Testing the NZXT H9 Flow RGB: Despite the Buzz, Worthy

We used the ATX configuration of our latest test kit to run the H9 Flow RGB through its paces.

Early in our test, we noticed that the H9 Flow RGB’s delivered configuration produced a buzzing noise typical of a fan blade passing in close proximity to another object, in this case, the case’s multi-fit fan bracket. After loosening the fan to move it away from the bracket and hearing the noise reduced, we decided to flip the array of front fans around as a secondary test configuration.

The flip barely affected the CPU temperature reading, but the impact was great enough to drop the H9 Flow RGB out of second place. With the front fans reversed, voltage-regulator temperatures went down, but GPU temperatures went up. Moreover, the winning GPU temperatures seem to prove the design theory of angling the fans in the manner chosen by NZXT.

The H9 Flow RGB is loud, even louder than the previous record-setting GT302 ARGB. Flipping the intake fan around to exhaust orientation helps a little, but our recommended solution for end users is to simply rely on motherboard-based fan controls to keep fan speed and noise down under all but the most extreme operating conditions.