Closer Look

The Comino GRANDO RM-S in the test configuration is a hefty beast, and lifting it onto my photography table was no easy feat. It comes in at 442 x 619 x 177 mm without any handles attached and weighs nearly 30 kg. After I had removed all the plastic wrap, I started a closer examination of the system with what I thought was the front, but is clearly the rear. There are two sections to this panel, with the larger of the two having large honeycomb cutouts for airflow to the 360 mm (triple 120 mm) radiator seen right away. This is a multi-port radiator with two spare ports at the top closed via hex head stop plugs, and these can be used down the line to drain, fill, or top off the loop, although Comino uses the reservoir for the filling. Comino's implementation of the pre-assembled system means customer won't have do so for a long time. There's a temperature sensor (air exhaust) just past the radiator, too. Labels on the bottom confirm the product name and have the serial number in and relevant OS credentials. The smaller section gives access to plug the three power chords into the three Comino-branded 750 W SFX 80+ Platinum PSUs, and you need to route the cable through a relatively thin cutout before turning on the switches on each power supply. The SFX form factor saves space, and Comino justifies the use of three 750 W PSUs as opposed to two 1000+ W PSUs or otherwise by stating that the goal was to have all three units operate at 50–70% load, the sweet spot for operating efficiency.


There's not a whole lot to see on the sides, which in the horizontal server rack orientation become the top and bottom panels. These are held in place with multiple hex screws which may be removed to access the internals we shall soon see. It is really the other side that is of primary interest—it is the de-factor front of the GRANDO RM-S.


On the top—or left outside of the vertical workstation orientation—is the reservoir with a see-through panel. We see coolant along with the deliberate air gap to account for any pressure changes in the loop during operation. Comino rates an operating temperature range of 3–38 °C for the system and a storage temperature range of -5–50 °C, which points towards an industrial-class coolant with anti-freeze. Of interest are also the two vandal switches with ring LEDs, and these are multi-purpose buttons that not only power on and shut down the system, but also act as navigation keys for the LCD display alongside. These are two pieces of a larger control and monitoring system built into the GRANDO RM-S, with the actual controller behind the reservoir on the inside. More of the honeycomb cutouts are on the thick metal panels, which provide a sneak peek at the hardware inside, including the various other temperature sensors. The motherboard I/O is next, with the ASUS Pro WS WRX80E-SAGE SE WIFI providing plenty of connectivity options, including WiFi-6, dual 10 GigE ports, plenty of USB Type-A and Type-C superspeed ports, and a multi-channel audio configuration for your speakers, source, headphones, and headset. Rounding off this view are the various video outputs from the integrated graphics card (VGA only) and four DisplayPort 1.4 ports per NVIDIA RTX A6000 GPU. No Type-C or HDMI here for those thinking of driving a VR development platform and testing native hardware, although a configuration for actual development would typically include test kits with other I/O options anyway.


With one of the solid panels removed, we get a much better view of the components inside, which confirms some of the used cooling components, including a single Alphacool NexXxos UT60 360 mm radiator for all the water blocks here. This is an off-the-shelf part with decent performance, although long in the tooth and supplanted by many in the same or lower thickness class. Perhaps Comino got a good deal moving from Hardware Labs in the Otto to Alphacool here, and it is still a very decent radiator in practice. It could also be a case of the components having been finalized a while ago, with Comino having validated it in the GRANDO RM-S and chosen not to update the system base. Two custom-designed stainless steel barb fittings connect flexible silicone tubing to and from the radiator. Notice that no fans are directly mounted to the radiator. In fact, doing so would have obstructed airflow to the PSUs slightly. Comino's compromise consists of three Noctua NF-A14 iPPC 3000 RPM 140 mm fans placed further into the chassis to create an intake airfield from the front and out through the radiator in the back. How well this works in practice remains to be seen, but Comino says it was done to use 140 mm fans for radiator and chassis cooling while making the most of the 4U width that can only fit a 120 mm radiator. The irregular placement of all the hardware means there is direct, unobstructed airflow from the fans to the air-cooled components too, which makes this an interesting design.


Comino has a short video showing how its custom water blocks are designed and manufactured. It ells us the CPU and GPU blocks are passivated copper-based, CNC-machined in what Comino calls a patented "deformational cutting" method to increase the contact and microfin surface area for improved heat transfer. The example GPU block in that video certainly has way more microfins over a much larger area than your average consumer product from the likes of EK and CORSAIR, and the GRANDO RM-S has five water blocks in total on the CPU and the four GPUs. Comino says the microfins are 250 µm thick with slimmer channels in between, and 2.7 mm high. The cold plate directly touches the core and VRMs too, which is nice. The passivated stainless steel and G1/4" threaded Comino custom-designed zero spill quick disconnect fittings also make it fairly simple to swap the CPU and/or GPUs with attached water blocks. These are all low-profile blocks, which is handy with the 1-slot GPU thickness as it has four GPUs fit into the GRANDO RM-S. The controller is behind the high-grade POM reservoir which houses ~450 mL of coolant and has two 18 W pumps for coolant flow throughout this otherwise restrictive loop. Identifying the exact pumps isn't easy, but Comino confirms that two 18 W Xylem DDC pumps in series are used.

Seen above are two videos that show the Comino GRANDO RM-S powered on and in standby, and with the system turned on. The display and controller work with temperature sensors, and the pumps and fans are connected to the controller for separately powered and monitored cooling outside of whether the motherboard is on or not. This decoupled cooling turns it on before the system for a check of all the components necessary to keep the CPU and GPUs running smoothly, and continues to run for a few minutes after the system is shut down, too. The video also gives an indication of ambient noise, which is a continuous gurgle in the 32 dB vicinity from a meter away, and the semi-open panels are what keeps it slightly louder than it would be in a more closed PC case. There are no coolant flow meters though, although the controller clearly handles it as seen in the idle monitoring scenario, with the various relevant metrics on screen.