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Scythe Fuma Heatsink Review

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Scythe has released its entry into the world of tandem tower heatsinks: the Fuma. Scythe heatsinks all have Japanese names, and the Fuma is no exception: it means “wind demon” in Japanese. It is powered by two Slip Stream 120 PWM fans. This sounds promising, but unlike the seemingly unending series of 160+ mm towers, the Fuma is less than 150 mm tall. Is this heatsink a wind demon or a mere dust devil? Let’s find out!

00The Company and the Heatsink

Scythe is a Japanese company who seems to have been around forever, but in 2002 Scythe Co. Ltd. originally started in Akihabara Electric Town, located in Tokyo, Japan. About the Fuma, they say it is a downsized Mine heatsink, which sported a 140 mm fan. They spent “countless hours . . . testing and optimizing,” and:

formed a cooling device measuring 149 mm in height. To compensate the smaller surface, our researchers put a great deal of effort in tinkering a new baseplate design as well as redrafting the fin structure. . . fitting the scarce space conditions of small PC cases.

Twin-Tower-Design

Fuma is made of two towers connected via six heatpipes to the baseplate. The twin-tower structure prevents mutual heating of the heatpipes while enhancing heat dissipation to the fins. Combined with further improvements, cooling performance increases, whereas compact dimensions are maintained. Fuma is predestined for ultra-quiet cooling but is an ideal overclocking cooler as well – at a very reasonable price.

Compact height without loss of cooling performance

With its height of only 149 mm Fuma is lower than other high-end coolers currently available. This way, conflicts with side panels are avoided – even with smaller PC cases.

Flexible Fan mounting

It is designed for the use of up to three fans*. If two fans are used, flexible fan positioning is possible. . . . Furthermore, flexible fan mounting increases compatibility – conflicts with memory modules will be avoided

* 2 fans are included

FUMA-dimensionsSpecifications

Model Name

FUMA CPU Cooler

Model Number

SCFM-1000

Intel® Socket
Compatibility

Socket LGA775, Socket LGA1150, Socket LGA1151, Socket LGA1155, Socket LGA1156, Socket LGA1366, Socket LGA2011 / 2011-v3

AMD® Socket
Compatibility

Socket AM2, Socket AM2+, Socket AM3, Socket AM3+, Socket FM1, Socket FM2, Socket FM2+

AMD® Note

The original backplate with screw mounting is needed for installation on motherboards with
AMD sockets. Check before buying to see if the backplate is secured by screws!
If your backplate uses plastic-pins, then mounting of this cooler is not possible.

Overall
Dimensions

137 x 149 x 130 mm / 5.39 x 5.87 x 5.12 inch (including fan)

Weight

920 g / 32.45 oz

Included
Accessories

Mounting parts for Intel and AMD sockets, wrench, thermal grease, and installation manual

Baseplate
Material / Heatpipes

Nickel-plated copper

Fan Model Name

Slip Stream 120 PWM

Fan Model Number

SY1225SL12M-CJP

Fan Dimensions

120 x 120 x 25 mm / 4.72 x 4.72 x 0.98 inch

Fan Noise Level

13.0 ~ 28.0 dBA

Fan Air Flow

5.6 ~ 79.0 CFM – 9.51 ~ 134.20 m³/h

Fan Speed

300 (±300 rpm) ~ 1,400 rpm (±10%) (PWM-controlled)

Static Pressure

~ 15.3 Pa / 0.01 ~ 1.56 mmH²O

Bearing Type

Sleeve Bearing

Max Power Input

2.4 W

Voltage

12 V

Amperage

0.20A

Packaging the Fuma

As is becoming more and more usual, the Scythe Fuma comes in fully recyclable cardboard packing. There are some lovely diagrams on the box. Standard marketing all around. These boxes look like they’re designed to hang on a rack in the Akihabara district or your favorite local store and purchased retail, on the spot.

Front of Box

Front of Box

Back of Box

Back of Box

Open the box and you see the fans protecting the heatsink. The Fuma, by the way, sits in a cardboard cradle. Under the fin stack cover you will find the accessories box sitting between the stacks.

Just to give you some proportion – those are 120 mm fans.

Opened Box

Opened Box

Fans and Box

Fans and Box

Looking at the Fuma

In the first picture, the heatsink is oriented as if the airflow is going from the bottom to the top, but this heatsink is designed for flexibility. Where you have tall RAM, you are able to orient the heatsink vertically so the airflow could run from top to bottom.

The next picture shows an oblique view of the tandem tower heatsink, this time without fans. The mirror-like fish on the top fins may be cosmetic, but it is attractive.

Airflow Goes Up

Airflow Goes Up

Mirror Top Fins

Mirror Top Fins

This view of the fin stacks shows the fins are fairly far apart, which is appropriate, since the fans included with the Fuma are known for their CFM, not their static pressure. You can also see where the fins are staggered, with half of them showing tooth-like leading (or trailing) edges. Finally, you can see the slot for the mounting bar.

A closer view of the slot shows the aluminum cooling nubs which adorn all Scythe coolers. These nubs also provide a means for keeping the mounting bar from sliding.

Tandem Towers

Tandem Towers

Slot in the Bottom

Slot in the Bottom

A closeup view of the Fuma’s bottom shows the cooling nubs again. You also get a different view of the sawtooth leading/trailing edges. The purpose of details like this is to provide turbulence in the airflow, improving the ability of the fins to transmit heat to the air.

Looking closer at the bottom shows the sticky protective film. Be careful of this, though. Once you pull it off, it loses its stickiness. You can also see the shape of the fins.

Fins and Cooling Nubs

Fins and Cooling Nubs

Sticker on Bottom

Sticker on Bottom

A closeup of the heatpipes shows they are fully covered by their fins. Whether pressed or soldered remains to be seen.

We can see the collection of small parts packaged with the Fuma. You will have to make do with the paper manual, though. A PDF copy is not yet available online. What you can see is the Y-cable for the fans – it sends only one RPM signal to the motherboard. There are also washers, TIM, and six fan clips! Indeed, Scythe provides you with the fixings for a three-fan extravaganza. We’ll have to take them up on that.

Heatpipe and Fins

Heatpipe and Fins

Small Parts

Small Parts

Mounting the Scythe Fuma

The Scythe mount comes in pieces. Here it is semi-assembled for you delectation. The nylon washers are loose. They go on threaded spacers which attach to the backplate. The mounting brackets are fastened to the spacers with flat-headed screws. And the entirety will be surmounted by the mounting bar, which is lying upside-down in front of the backplate. Follow the directions. Read the manual. Check your work. Those mounting brackets can go on upside-down. So can the mounting bar. Be careful. Read twice and assemble once.

The second picture shows the backplate from behind the motherboard. You will note this backplate is not position-agnostic. Orientation matters. Line it up with the socket screws in advance.

Backplate and Mounting Gear

Backplate and Mounting Gear

Backplate on Motherboard

Backplate on Motherboard

Now let us look at the flatness of the contact surface. In the first picture the blade is aligned with the airflow. Along this orientation the surface is not curved.

When the blade is set at right angles to the airflow a convexity appears. It doesn’t look like much. It is probably safe for my CPU – for a short time only. This means the heatsink will dwell on the CPU for a day, but no more.

In Line with Airflow

Blade in Line with Airflow

Blade Across Airflow

Blade Across Airflow

The contact surface itself is very like a mirror. Those are the basement rafters you see reflected in the surface.

The second image shows the screw holding down the mounting bar. First of all, note, the mounting bar is oriented with the sides up – it makes a sort of U here. Second, note, the mounting bracket has the middle portion up where it is closer to the pressure screw. Finally, note, the pressure screw has no natural stop. You can really muscle on the mounting pressure if you try. Other manufacturers have special shoulders to stop the screws, with springs applying the pressure. Here, the screw applies the pressure.

Mirror Contact Surface

Mirror Contact Surface

Closeup of Mount

Closeup of Mount

Fans Clip to the Fuma

You can tell Scythe has been in the heatsink business a long time. Their fan clips work. You put the clips on the front fan, and with two fingers, it’s mounted. Getting the fan off is just as easy. Pull on the clips and they disengage from the fin stack, and off the fan comes. The second fan is where it gets – interesting. Those fin stacks are close together. If you put the clips on the fan and then try to slide it down, the clips interfere with movement, catching on the fins. So, don’t put the clips on first. Slide the middle fan down to the bottom. Then move it to the side and put on one clip. Then move it to the other and fasten the other clip. Now mount it. It’s surprisingly easy to do. One thing about the fins: you can see right through the front stack to the other side and spot the other clip there.

Second Image: Here is the Fuma with the third fan clipped to it. Notice the clip handles are far enough apart to avoid interference with each other. Smart engineering, that.

Two Fans on Fuma

Two Fans Clipped to Fuma

3 Fans Clipped to Fuma

3 Fans Clipped to Fuma

RAM

The pictures show you what happens when you put medium-tall RAM with the Fuma: the fan won’t go all the way down. You can also see, because of how the heatsink is mounted, the front fin stack sits just behind the RAM, so the fans in the middle and pull positions would not interfere with any RAM. However, those of you thinking of buying RAM should note these tests were performed with low profile RAM, which allowed me to use a front fan without moving it upward. There is no reason in these days of low voltage RAM for you to get RAM with tall heatsinks outside of aesthetics.

RAM Gets in the Way

RAM Gets in the Way

Get Low-Profile RAM

Get Low-Profile RAM

Setup for Testing

CPU

Intel i7 4790K @ 4.5 GHz

Vcore

Set to 1.23 volts, read at up to 1.248 volts

Vrin

Set to 1.8 volts, read at down to 1.704 volts

GPU

Intel HD Graphics 4600, integrated into the i7 4790k

Motherboard

Gigabyte Z97X Gaming-7

RAM

Crucial Ballistix Sport Ultra Low Profile; 2 x 4 GB – 8 GB total

SSD

Samsung 840 EVO 500 GB + 1 TB

PSU

Seasonic SS-460FL 460W Fanless

Heat Stress Software

Linpack with AVX2 – LinX 0.6.5 user interface

Operating System

Windows 10, 64-bit

Core Temp Log

Real Temp

Ambient Temp Log

Digital TEMPer USB Thermometer, with logging software

Sound Pressure Meter

Tenma 72-942

The Fuma was mounted with a 5mm diameter blob of TIM. The TIM blob was stiff enough to stand on its own. The TIM was allowed time to spread, and after a day the heatsink was tested with Linpack running AVX2 extensions. Linpack is the software Intel engineers use to maximize the heat produced by their CPU’s. Hence it is the best software to test overclocking. But Linpack runs in surges. When the temperature is graphed, you see ragged plateaus. In looking for cooling solutions, you want to know how well a heatsink cools those plateaus – you won’t care about the valleys. So the temps under 70 °C (the valleys) were ignored in analyzing core temps.

Each test run was 30 minutes in duration. The last 20 minutes of each run was measured, and the core temperature logs were analyzed in Open Office spreadsheets. An Intel chip reports its temps in one degree increments, so for best accuracy these reports should be averaged in aggregate. Here the core temps were measured once a second, resulting in 1200-line spreadsheets.

The digital thermometer measuring air temp reported its measurements in increments of 0.1 °C. The ambient temperature was measured every five seconds, resulting in 240-line spreadsheets. The mean ambient temp was subtracted from the mean core temps, resulting in a net temp for each run. Finally, the several net temps were averaged.

The Sound Pressure level was measured 1 meter from the heatsink, with the motherboard set vertically, the way it would be in your case. The ambient noise for this testing was 30.5 dBA. So the net SPL is the sound pressure level measured at 1 meter, less 30.5 dBA.

The Fuma was first tested by lightly screwing down the tensioning screws. This was the “low pressure” mount. After three runs the screws were tightened down to the limit my fingers would tighten the long shaft screwdriver. I could have closed my hand around the screwdriver and applied more pressure, but discretion was the better part of valor here, so finger tight was the limit. After three runs with two fans, I did two runs with three fans, with all three being PWM Slip Stream fans. Finally, I swapped out the PWM fans and put in three fixed-speed fans. Two of them were Slip Stream 120DB fans with nominal 800 RPM speed, and one was an older Slip Stream with a sleeve bearing, also nominally 800 RPM. The reason these latter two sets were only two runs apiece was because I wanted to get them done in time to remove the heatsink before it went a second day on the CPU. In any case, the net temps were 0.1 °C between the first two runs, and 0.2 °C between the second two runs.

98

Just to be clear: the only difference between the Low Pressure set and the High Pressure set was the applied pressure. The mounting was the same. The sole difference was some turns of the screwdriver on the tensioning screws.

Results of Testing

First of all, look down to the bottom of the chart. The Fuma, mounted with low pressure, still made it to the first level of cooling. I did not have to back off the voltage or the overclock to measure this heatsink’s cooling. This is indicative of major league performance.

Next, you should note the move from Low Pressure to High Pressure mounting improved this heatsink’s cooling by more than 11 °C. This is why a rival made his bitter comment about “some OEM’s” making heatsinks that applied more than Intel’s allowed pressure: the amount of pressure you apply in your mounting can make a huge difference in your cooling.

Third, note, adding a third fan only decreased the Fuma’s cooling by 0.6 °C. The net SPL only went up 2 dBA, but you could really hear those two decibels.

Finally, look at the performance of the three 800 RPM Slip Streams. This cooling was excellent, and you could barely hear it.

FumaA

MSRP

$42.95

Conclusions

If you are careful not to “overtighten” this mount, the Scythe Fuma looks to be an excellent heatsink. How can a 149 mm tandem tower out-cool heatsinks much larger than it is? One suspects the convexity of the contact surface and the pressure applied by the mount had something to do with it. Heck, we already proved mounting pressure can make a huge difference in cooling performance.

Yet the Fuma really can cool well. And with its low MSRP, it will be a major bargain when it is released to the general public.

The fact is this heatsink can use 120 mm fans not known for high static pressure, this is a plus. You could use any fan with this heatsink – just reach into your collection. For heatsinks, I don’t trust sleeve bearing fans though. You would do better to get a pair of PWM Slip Stream DB 120 fans for it – the DB stands for Double Ball bearings. Or you could get three 800 RPM Slip Stream DB 120 fans and not hear the heatsink. The possibilities are endless.

So Scythe doesn’t want you to “overtighten” their mount. But leaving the issue of the unprotected screws aside, this is a really easy mounting system to use. You can see where a lot of thought has gone into this mount. Just don’t drop the screws.

The flexibility in setting up your fans is greatly appreciated. This means you can use this tandem tower heatsink even when you have high RAM.

Overall, then, this is a really cool heatsink.

99

Scythe Fuma Pros

  • Excellent cooling performance
  • Flexible fan arrangements
  • Two PWM fans provided
  • Easy mounting system
  • Packing is fully recyclable
  • Low MSRP

Scythe Fuma Cons

  • You must take care not to overtighten your mounting screws
  • Manual is not online – yet
  • Screws are not attached to heatsink – easy to lose

Click the stamp for an explanation of what this means.

Ed Hume (ehume)

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Discussion
  1. "It is probably safe for my CPU – for a short time only. This means the heatsink will dwell on the CPU for a day, but no more"

    I really want to like this heatsink but losing 10c cooling power by using a standard "safe" mounting system is a bummer. I hope they come out with a 140mm version and perfect it. I Like the idea of what's basically an nh-d14/15 made for low flow and a single fan. The way they kept the spacing between the fin stacks is perfect. No need for extra fans since the one in the middle gets proper flow through both stacks and you don't have to add all that extra weight unless you feel like it.
    k2w2yut
    ehume, thank you for your reply and concern.

    Scythe Jyuni 120 DB is only 1,000 yen (while Fuma/Ninja4 is 5,000 yen), replacing fans after 1-2 years still keep the budget under nh-d15.

    However, considering your comment, pressuring my Haswell should be for fine now but I plan to upgrade soon, so ... safety costs performance here.

    Since I'm looking for a AIO's level performance here, the bigger D15/R1 may be my better chance.

    I really hope for a bigger cooler from Scythe, my first cooler for core2Duo was also theirs and their price/performance is always really good.


    The Fuma is big, and it uses two fans, even three fans. I think you won't see larger. Even the Mugen 5 is not larger.

    I like the Gentle Typhoons and the San Ace fans best, though now that the Kaze Jyuni is dual ball bearing races, the fans should last a long time. Look at my results for the Fuma. Three 800 rpm fans, and only the SPL meter can hear it. You certainly won't. Now that's a quiet heatsink.
    ehume, thank you for your reply and concern.

    Scythe Jyuni 120 DB is only 1,000 yen (while Fuma/Ninja4 is 5,000 yen), replacing fans after 1-2 years still keep the budget under nh-d15.

    However, considering your comment, pressuring my Haswell should be for fine now but I plan to upgrade soon, so ... safety costs performance here.

    Since I'm looking for a AIO's level performance here, the bigger D15/R1 may be my better chance.

    I really hope for a bigger cooler from Scythe, my first cooler for core2Duo was also theirs and their price/performance is always really good.
    Good questions!

    The variation of results with increasing mount pressure is to be expected. Whether a Skylake will be safe with this long term I can't say. However, Scythe has put out screw stops for some of its coolers and not others. Ask Scythe.

    I know that Scythe coolers are cheap, but you must factor in your need to replace those sleeve bearing fans when they go bad. Admittedly, that will take some time but you should prepare for that day. You can either get 1300 rpm Scythe Kaze Jyuni 120 DB fans or you can get a pair of 2050 rpm PWM Gentle Typhoons (those are my favorite fan).

    Even though they contributed to dishing my CPU, I like these Scythe heatsinks. The Ninja 4 is pretty. The Fuma cools well, even with low-rpm fans. (If you are doing that, get three matched lowspeed fans.) Even though it was difficult to mount, my daughter still uses my old Mugen 2 (with a pair of San Ace fans). You could say I'm a "fan."
    Firstly, thank you for your review especially, about the pressuring on mount plate.

    Many (or all other?) never mentioned about this including Japanese's reviewer themselves.

    Since they tested all cooler in a roll, I hope for a consistency of pressuring here.

    They concluded that ninja4 is the best due to, same performance as CRYORIG H5 but much lower price.

    I live in Japan and Scythe's price is much cheaper compared to imported stuff.

    (Sorry for Japanese contents)

    Ninja4: http://ascii.jp/elem/000/001/125/1125389/index-5.html

    Fuma: http://ascii.jp/elem/000/001/125/1125389/index-6.html

    H5: http://ascii.jp/elem/000/001/126/1126353/index-3.html

    So my questions are:

    Should I worry about high pressuring the cooler on a thinner Skylake/Kabylake chip?

    If yes, should I still expect these coolers performance as NH-D15? or I should buy the pricer from others (since both are top-line of Scythe).

    And finally, what is your opinion about Fuma/Ninja4 result vairation.

    Thank you
    Well ...

    I went in the shop this morning and grabbed a Scythe Ninja 4.They had a mugen 4, a shadow rock , and ninja 4 ...

    Scythe Kama angle rev b was not meant for AM3+ but for AM3...It has an offset problem on am3+ ... anyway i will post results after results...
    I only buy etail cause I live in a small town and brick and mortar technology stores like Frys or Microcenter are no where near. When it comes out on NewEgg or Amazon I'll look at it again.
    Thx for the answers.I am from Europe and here they are both available so it's a matter of choice.Both of them are out btw.

    Here is a frostytech review of the Ninja 4

    http://www.frostytech.com/articleview.cfm?articleID=2793
    trents
    Can't seem to find any place to buy this thing.


    That's because it's not out yet. I thought that might be the case. That's why I said the Ninja 4 is OK.
    myststars
    Hi

    I have a Scythe Kama Angle rev B that is pretty old and the original fan died.For some time i have an FX8370 not overclocked and seems can't handle it without an exhaust fan.The tim is an MX-2 and the fan is a Lepa BOL.QUiet 1600rpm.I tried many fans combination and it barely keeps the temps under 60 C in games like Witcher 2 enhanced edition.With exhaust fan i can play Witcher 2 without the mainboard screaming at me that it passed 60C point..

    So my question is ... Scythe Ninja 4 or Fuma ?

    I like quiet over performance btw

    My rig:

    FX8370 non-oced

    8gb ram Kingston

    Gigabyte 970A-Ud3p

    GTX 970

    PSU: Corsair 750HX

    Asus Xonar ST

    Case: Nexus Caterpillar V1

    Windows 10

    Btw i like how the reviews are written...Very practical and little observations that i couldn't find in other reviews..

    Best regards


    Make sure you use RAM low-profile RAM. Either heatsink will do nicely, though the Fuma is better, IMO. But if it is not available, the Ninja 4 will do.
    Hi

    I have a Scythe Kama Angle rev B that is pretty old and the original fan died.For some time i have an FX8370 not overclocked and seems can't handle it without an exhaust fan.The tim is an MX-2 and the fan is a Lepa BOL.QUiet 1600rpm.I tried many fans combination and it barely keeps the temps under 60 C in games like Witcher 2 enhanced edition.With exhaust fan i can play Witcher 2 without the mainboard screaming at me that it passed 60C point..

    So my question is ... Scythe Ninja 4 or Fuma ?

    I like quiet over performance btw

    My rig:

    FX8370 non-oced

    8gb ram Kingston

    Gigabyte 970A-Ud3p

    GTX 970

    PSU: Corsair 750HX

    Asus Xonar ST

    Case: Nexus Caterpillar V1

    Windows 10

    Btw i like how the reviews are written...Very practical and little observations that i couldn't find in other reviews..

    Best regards