Scythe Gets Aggressive: Budget CPU Coolers & FUMA Overhaul

Fuma 3 Revision B

First up is the Fuma 3 Revision B, which sees changes to its mounting solution over its predecessor. This tweak increases pressure by adding a nut to the screw and applying more force to the center of the crossbar, which increases overall pressure centrally from the coldplate to the IHS. This should theoretically help the coldplate better conform to the curvature of Intel style integrated heat spreaders.

As you can see from the image above, Scythe has added a nut that its screw would go through to apply pressure in a pin-pointed way. This should solve some of the Fuma 3’s performance limitations we’ve seen. Scythe says that the cooler should see a 2-3 degree thermal improvement as a result of its changes under a high but unspecified heat load. This would not apply universally, as the thermal improvement is contingent on the amount of heat the cooler is handling.

The company also shaved down the backend of the cooler to help with Mini-ITX clearance, which you can see in the NR200P showcase build that Scythe had present. The trimming of the plastic allows the top of the cooler to just barely fit within the chassis of the Cooler Master NR200P while still allowing the side panel to close fully.

The Fuma 3 Revision B will retail for the same price as the plain Fuma 3 predecessor, which is currently about $50 online.

Shuriken 3

Next up is the Shuriken 3 downdraft cooler, which is a follow-up to Scythe’s Shuriken 2. The Shuriken 3 is a major departure from the Shuriken 2: The new cooler is ~39mm tall, down from the Shuriken 2’s 58mm height. These shouldn’t be thought of as directly comparable.

The Shuriken 3 integrates the cold plate into the finstack, which recesses it and shrinks the height. This means it provides less overall finned surface area, which would make performance technically worse, but the goal for Scythe here is to make something that can fit into even lower profile scenarios. The company stated that it aims to compete directly against Noctua’s NH-L9i in this space.

The Shuriken 3 introduces cut-outs on the side of the fan. Scythe was willing to share prototypes of the new fan design with us, stating that it tested cut depths (in the plastic of the fan chassis) varying from 2mm to 6mm. Scythe’s stated reasoning is that this reduces the amount of backpressure on the fan blades by allowing more area for the air to exit. Simultaneously, it would also allow slightly more finned surface area to directly contact air flowing from the fan. We’d have to test this to know whether the concept works as planned.

Scythe started its prototyping for this on an existing 120mm fan by using a simple hand saw to cut away the border, later making one-off prototypes and printed test vehicles to rapidly concept the idea. 

For some of these new coolers, Scythe is soldering the heatpipes to the fins rather than using a press-fit solution, which the old Shuriken design used. Soldering the heat pipes with the fins will, Scythe says, improve thermal conductivity and efficient heat transfer, which should help performance. In our recent visit with Thermalright, the competitor stated it is also moving to soldered heatpipes with fins, but the stated reason was “quality.” Thermalright said that it did not observe an impact to thermals by moving to soldering from press-fit, so the companies appear to have differing opinions or results.

The Shuriken 3 also has a larger cold plate, which is geared for more modern CPUs. The Shuriken 3’s fan is also different, using a Kaze Flex 92 AH, which is the new cut-border fan.

Finally, the mounting kit is also different. The Shuriken 3 will cost $40 when it launches in July.

Scythe Magoroku 

Next up is the Magoroku cooler, which is inspired by the Scythe Fuma 1. The Magoroku is currently a prototype that’s not ready to launch. It intends to provide an improvement on the Fuma series while sacrificing some memory clearance compatibility.

Compared to the Fuma 3, the Magoroku has straighter heat pipes, which Scythe claims produces a 6% thermal conductivity improvement compared to going with a more curved solution. The curvature of the pipes in the Fuma series provides increased RAM clearance. We’d like to test this and have asked the company to send us 2 versions: 1 with straight pipes and another with curved pipes, but both at equivalent lengths. This would be a follow-up to our coldplate engineering research piece we ran previously.

The Magoroku will use two Wonder Tornado fans, which are 120mm fans that are 25mm thick. This should provide higher performance than what you would see on the Fuma series, as the Fuma coolers use a short front fan (also for RAM clearance) that’s cut-down to 15mm. Slim fans lose significantly on the pressure performance, which affects their ability to efficiently push air through a dense tower. The thicker Wonder Tornado fans will contribute significantly to the claimed performance advantage of the Magoroku. It’s more of a Peerless Assassin approach to cooling.

Scythe says the Magoroku will have 6 or 7 heatpipes. The solution is not finalized yet.

In terms of height, the Magoroku will be 154mm tall, which is the same as the Fuma 3. The mounting solution will also be the same as the Fuma 3. 

The Scythe Magoroku doesn’t have a release date yet, but Scythe is targeting the end of the year. The company says it’s still waiting on information from Intel regarding Arrow Lake to finish its design. Scythe is targeting a price point under $40, which would be very price competitive with Thermalright.

As some backstory, Scythe says the name comes from a famed knife smith from Japanese culture and history.

Big Shuriken 4

Finally, Scythe showed us its Big Shuriken 4 prototype, which doesn’t have a price or release date at the moment. 

Compared to its predecessor, the Big Shuriken 3, the Big Shuriken 4 is taller to reduce the mechanical conflict with the board and has 1 more heat pipe, moving up to 6 from 5. Scythe also says that its heatpipes have better bonding this time around, also moving to soldering.

The Big Shuriken 4 also has a new larger cold plate.

Its fan also has 4 holes on the sides for the reasons we outlined above, making use of the new approach to fan design that Scythe appears to be rolling-out to its coolers.

We had a lengthy engineering discussion with Scythe founder and engineer Kitagawa San, who hopes to send us one-off units for future educational engineering videos and thermal tests. We previously worked with Scythe on the coldplate engineering piece linked above, with new ideas emerging from the cut fan border design and the heatpipe straightness topic.
For additional cooler coverage, check out our Thermalright booth visit from Computex or our Thermaltake vapor chamber (3DVC) discussion in HW News.