Heatpipes, dual fan capability, big and tall, blow-across airflow, hypro bearing fan with wide-range speed controller: These are the core features of Scythe’s new multi-platform CPU cooler. The FCS-50 features many thin fins, the flat Heatlane heapipe, and some unique design features. It fits well in Scythe’s eclectic HS stable. How cool & quiet is it?
Aug 11, 2003 by Mike Chin
| Product | Scythe Heatlane FCS-50 heatsink/fan for P4, A64, socket -A and socket-370 |
| Supplier | Scythe Japan, Scythe-USA |
| Price | US$49.95; Euro$49.95 |
Reviews of Scythe cooling products always seem to require commentary on their uniqueness. The FCS-50 is no exception. This heatsink fan is a canny mix of the TS Heatronic patented flat heatpipe technology with flow-through forced air cooling and a versatile mounting system that’s compatible with every type of desktop CPU currently sold.
FCS-50, front off-angle view.
FCS-50, back off-angle view.
At a quick glance, the FCS-50 shares some obvious characteristics with the new rash of tower style heatsinks:
- It’s tall rather than wide.
- It’s big.
- The fan is mounted sideways and blows across the HS rather than down from the top.
As you will see, there are many differences that mark the FCS-50 as distinct from the rest of the tall blow-through HSF crowd. One of the claims made is that this product satisfies the needs of both performance overclockers and quiet PC enthusiasts by means of a fan whose noise / speed can be varied from a maximum of 46.1dB @ 4600rpm to a minimum of 15.1 dB @ 1300rpm. That is certainly an enormous range, considerably wider than with most fans and speed controllers we’ve seen
Specifications and features from Scythe’s web page:
| SPECIFICATIONS Model Name: Scythe Co., Ltd., Japan Pentium 4 (socket 478) all speeds Athlon 64FX (socket 754) all speeds |
| FEATURES * Top * Patented Heatlane Technology Scythe’s unique R.C.C.M. (Rigid Core Clamping Mechanism) makes installation * Cross-Platform Compatibility |
PACKAGE
This is what you find in the colorful box:
- FCS-50 HS + fan attached (w/ hardwired speed controller)
- 2 bottom mounting clips (one missing in the photo below) with screws for them
- 1 pair of long spring-loaded machined screws
- small amount of thermal interface material
- 2 instruction sheets, English and Japanese
As the specifications on the previous page details, the FCS-50 comes with hardware to allow its use with Sockets A, 370, 478, 754, 939 and 940. This is achieved by separating the mounting mechanism into two parts:
- Screws and anchors for them on the main HS, and
- A detachable platform-specific “clip”.
Here are the clips:
Mounting “clips” (from left):
Socket-A/370, socket-478, and 2-spring loaded long screws for all the flavors of A64.
FCS-50 shown with
A64 mounting clips: Ingeniously, the spacing of the holes in the side screw anchors or flanges is set to match the A64 mounting posts perfectly, eliminating the need for bottom clip.
DESIGN
As the photos show, there are thin fins rising up from the base in conventional vertical fashion. There are also fins that run laterally across the width of the HS above the bottom fins. A three-sided U-shaped shroud covers all the fins and provides fan mounting holes on two sides of the fins. The photo below shows the blow-through aspect clearly.
The base of the heatsink is flat and very smooth, perhaps not the very smoothest ever, but plenty smooth enough. It appears to be nickel-coated copper. The material is not specified. The fins are clearly formed of very thin aluminum strips. They all show signs of being soldered together.
1″ tall EAR fan grommet sitting atop smooth and flat FCS-50 base.
You may recall from our eOtanachi EPIA-M fanless cooler/case review that the Heatlane heatpipe is flat and wide instead of tubular. Here’s a photo of the flat heatpipe from that review.
So where is the Heatlane heatpipe so prominently listed among the FCS-50 features? Let’s look closely.
Image highlighted with Photoshop to show the hidden heatpipes.
What they have done is to take a length of the flat Heatlane heatpipe, and folded it in a loop to run two layers between the bottom HS fins and the base, and wrapping run it up and around the fins. The fins are soldered to the heatpipe, of course. Here’s a rough side profile drawing of the heatpipe/HS:
The heatpipe loop is the frame to which the fins and the base are attached.
The heatpipe wraparound design ensures very even distribution of the heat from CPU throughout all the radiating surfaces. The heatpipe efficiently spreads the heat via the working fluid within, which is HFC134a and butane (both with with zero ozone damage potential). This means that the full cooling potential of the surface area is utilized, unlike in conventional heatsinks where thermal resistance reduces the efficiency of long cooling fins close to their ends. Here, no point in the fin is more than ~3.5 cm from the heatpipe. (For those interested in the technical details, please check this page from TSHeatronics, the originator of the Heatlane heatpipe technology: http://www.tsheatronics.co.jp/english/technology/index.html)
Because the cooling air in this HS flows through it in a plane parallel to the surface of the motherboard, the possibility of evacuating the hot air via the back case exhaust fan is very real. It is a configuration that helps to minimize the heat in the PC, which is a significant factor in keeping all thermistor-controlled fans (most commonly found in power supplies) from ramping up in speed.
This does mean that the HS must install on the board with the fan pointing towards the back panel. It will not be this way with all motherboards. On all the P4 boards in the lab (an Intel 845 board, a VIA P4B400 board, and a recent AOpen 865 board), the socket / retention frame was found to be configured the “correct” way.
INTEGRATED FAN
The fan is secured to the frame with four screws in the corners. Later, it was discovered that it is just a bit too short for the Panaflo 80L, which is a smidgen thicker than the stock Scythe fan. Like the fan integrated with the Scythe Kamakaze and the Scythe Samurai coolers, it has a hardwired fan speed controller, a knob mounted on a plate for a PCI cover. So it mounts on the back panel of the case, although many DIY types will probably remount the control on the front panel.
Nice, smooth feel on fan speed control.
As you can see in the photo of the label, the fan is rated for a whopping 0.55A at 12V, or about 7W. This is one reason the fan is powered from a 4-pin PSU connector, and only feeds an RPM monitor signal to the motherboard fan connector. The current draw is probably too high for many fan circuits on otherboards.
A very powerful fan.
EXTRA AIRFLOW ACTION
You will have noticed the shark’s gill-like slots, four on each side of the HS outer frame. They do serve a function: To draw in extra air by the vortex or suction created by the fan’s airflow as it rushes through the tunnel of the fins. (It probably works much like the augmented fan design by Lemont Aircraft [also Millenium Thermal Solutions] which Panaflo adopted some time ago; the high speed of the blades’ outer edges draw extra air in through slots in the frame, providing slightly higher airflow without any more noise.)
This is Scythe’s explanatory drawing of the airflow pattern through the FCS-50.
Finally, airflow can be augmented even more dramatically with the addition of a second fan in a push-pull configuration. Two identical fans in push-pull does not increase the maximum theoretical airflow over one fan in a low impedance setup (read: open tunnel). But with higher impedance, such as tightly spaced fins in a heatsink, the greater pressure of the dual fans ensures that airflow does not drop as much as with just one fan.
INSTALLATION
The FCS-50 was installed on the Intel D845PEBT2 motherboard used before for many heatsink reviews. The instruction sheet tells you to begin by clipping the correct mounting frame or clip on to the CPU socket itself. Here’s a scan of the instruction drawing:
It’s a simple step. Here’s how it looked after this step was taken:
Metal frame or clip mounted to plastic HS retention bracket on board.
Next, the HS is placed on the CPU (after thermal interface material is applied). It goes into place fine.
The next step is to use the two shorter screws to apply tension between the HS base and the CPU. The metal frame gets pulled up and tension applied to the four corners when it clips to the plastic retention bracket.
This step is not so simple, even with the test platform out in the open, rather than installed in a case. The screw holes are small and difficult to line up. I would recommend that if you have difficulties getting the screw in with the motherboard already mounted in place, you should at least remove the PSU to give yourself more room to see and work in.
A bit of an infernal screw, at least for me.
You are instructed to insert and turn the screws evenly and gently to avoid overtightening, but there is no indication of how you can tell when you have overtightened. I played it by feel and sight, lining the two sides up for about the same gap between screw anchor on the HS and the metal clip, and kept turning till it felt too hard to turn some more. I was secure in the knowledge that the P4’s heat spreader would protect against any damage, but this is not true for AMD XP or P3 CPUs that don’t have a heat spreader. So do be careful and gentle!
Here’s the FCS-50, installed and ready to go on the test platform. It took only 5 minutes, even with time for photos.
Ready for action: It stands ~0.8 cm taller than the top of the PCI card.
TESTING
The core of the test system is very similar to that used in the past, but a few minor components have changed and test tools added:
- Intel P4-2.8A The Thermal Design Power of this P4-2.8 (533 MHz bus) is 68.4 or 69.7W depending on the version. As the CPU is a demo model without normal markings, it’s not clear which version it is, so we’ll round the number off to ~69W. The Maximum Power, as calculated by CPUHeat & CPUMSR, is 79W.
- Intel D845PEBT2 motherboard – Intel 845PE Chipset; on-die CPU thermal diode monitoring
- Panaflo FBA08A12L1A 80mm DC fan
- nVidia GF400MX VGA card (AGP)
- OCZ DDRAM PC-3700, 512 MB
- Seagate Barracuda IV 40G 1-platter drive (in Smart Drive from Silicon Acoustics)
- Enermax UC-A8FATR4 multifunction monitor/fan controller w/ thermal sensors
- Seasonic Super Tornado 300 (Rev. A1)
- Zalman Multi-Connector (ZM-MC1) and Fanmate1 voltage controller
- Arctic Silver Ceramique Thermal Compound
- Two-level plywood platform with foam damping feet. Motherboard on top; most other components below. Eases heatsink changes and setup.
- CPUBurn processor stress software
- Intel Active Monitor and Motherboard Monitor software to show CPU temperature
The ambient temperature in the test lab was 22°C. Ambient noise in the lab was ~21 dBA. For the acoustic testing, the HSF was moved to a quieter room which measured ~16 dBA. Maximum load temperatures were recorded 30 minutes into a CPU stress test with CPUBurn.
TEST A: Stock Fan
The FCS-50 was tested at four fan settings, mid being the midway point on the control knob. The noise was measured separately with the HSF in a quieter space with no other equipment running at all. Note that by itself in free air, the fan’s noise drops by 1~2 dBA at lower speeds and 3~6 dBA at high speeds.
The borderline setting was established by ear. It is the level at which the very quiet components of this test rig still mask the HSF noise. In other words, if the fan was run any faster, I would start to hear it as a distinct noise source, separate from other noises, from a couple feet away. Inside a case, it’s likely to remain masked to a slightly higher speed.
| STOCK FAN | Idle temp* | Max temp* | Temp rise* | °C/W TDP | °C/W MP | Noise** |
| Max (4800 RPM) | 34 | 39 | 17 | 0.25 | 0.22 | 50 |
| Mid (2330 RPM) | 39 | 44 | 22 | 0.32 | 0.28 | 36 |
| Borderline (1600 RPM) | 41 | 52 | 30 | 0.43 | 0.38 | 22 |
| Min (1330 RPM) | 42 | 56 | 34 | 0.49 | 0.43 | 20 |
| * Idle, Max and Temp rise figures all in °C. ** Noise in dBA @ 1m distance. TDP (Thermal Design Power of CPU) = 69W MP (Maximum Power of CPU) = 79W | ||||||
1) At Maximum speed, this hypro-bearing fan is a screaming, whooshing monster. The airflow is strong enough to be felt over 8 feet away. The cooling performance is super, so perhaps it’s a dream for an overclocker, but it’s a nightmare for me. It’s a smooth not grating sound, but it’s loud. 50 dBA/1m is 4 dBA louder than cited in the specs, but the difference is essentially meaningless; either level is too loud. It is loud enough to be heard faintly from two rooms away at the top of the stairwell on the next floor. Great performance, but as Scythe implies, it is the Mr. Hyde side of the FCS-50 (2-in-1, remember?).
2) At Mid speed, the performance holds up well; it is still very good. A 22°C rise over ambient at max is nothing to scoff at. The noise is still too high for SPCR, but might be acceptable in a noisier environment than mine inside a well-damped case. The main character of the noise is turbulence noise and some whine. Basically fairly benign and smooth, but there’s just too much of it.
3) The Borderline speed actually represents a speed setting technique I’ve used intuitively for years without ever writing about it before. Every system has components whose noise just can’t seem to go below a certain level. When another fan is introduced, adjust its speed so that when you just start to hear it, you back off just a touch. At this point it is at the borderline of audibility. The new fan’s noise is masked by the other components in the system and so adds no significant noise.
The borderline speed with this HSF in this system turned out to be 1600 RPM, at which speed it produces 22 dBA/1m in free air. It’s very quiet, and performance is still decent. If you add 10°C to the ambient simulate the inside of a case, the P4-2.8 would be at ~62°C, which is perfectly safe. (Remember that’s after a continuous half hour of the toughest CPU load we can find.) The basic sonic character of the fan is a bit of turbulence whoosh along with a bit of buzzing from the bearing, somewhat higher than I find on Panaflos. That’s the only significant bearing/ motor artifact. It’s not bad at all. Inside a case it could be inaudible.
4) At Minimum speed, the fan is very quiet. There is no turbulence noise, but the buzzing mentioned above seems a bit louder, and a humming noise also ensues. It’s not as quiet as a Panaflo 80L at 7V. Still it’s probably good enough for most users. The cooling power is now borderline. 34°C over ambient at load puts the CPU at 66°C, which is starting to get into uncomfortable territory. It’s probably still perfectly usable unless your ambient and case temperatures are higher, and you routinely push the system to such high continuous loads over long periods of time.
TEST B: Panaflo 80L Fan
The FCS-50 was tested with our reference Panaflo 80mm hypro bearing, low speed fan at three voltages: 12V, 9V and 7V. The noise was measured separately with the fan on the HS in a quieter space with no other equipment running at all. Note that by itself in free air, the fan’s noise does not measure or sound any different except at the 12V level. Airflow from the Panaflo is probably too low for turbulence in this HS to cause extra noise. As mentioned previously, the four screws provided are too short for the Panaflo, which is a touch deeper than the Scythe stock fan, but I scrounged up some slightly longer screws to do the job.
Reference Panaflo Fan Summary
| Table 1: Panaflo FBA08A12L1A Speed, Airflow and Noise | ||||
| VDC | 12V | 9V | 7V | 5V |
| RPM* | 1880 | 1520 | 1230 | 760 |
| dBA @ 1m** | 24 | 19 | 16~17 | ??? |
| * RPM was measured on two Panaflo samples using MBM5 along with a custom-made tachometer board provided by Fan Control, an electronics-savvy member of the SPCR Forum. This device allows accurate readings of fan speed down to much below 1000 rpm, which is usually not possible with standard on-board sensors. The readings from the two fans were averaged for the above table. ** dBA@1m noise figures were measured with the fan suspended in free air without any load. The noise could not be measured consistently at the 5V drive level because the ambient level in the acoustic lab was too high. My guess: ~15 dBA/1m, maybe lower. | ||||
FCS-50 + Panaflo Results
| PANAFLO 80L | Idle temp* | Max temp* | Temp rise* | °C/W TDP | °C/W MP | Noise** |
| 12V | 38 | 45 | 23 | 0.33 | 0.29 | 25 |
| 9V | 41 | 51 | 29 | 0.32 | 0.37 | 19 |
| 7V | 45 | 59 | 37 | 0.54 | 0.47 | 17 |
| * Idle, Max and Temp rise figures all in °C. ** Noise of fan on HS in free air, in dBA @ 1m distance. TDP (Thermal Design Power of CPU) = 69W MP (Maximum Power of CPU) = 79W | ||||||
1) With the Panaflo at 12V, the FCS-50 turns in a very nice performance. It is certainly good enough for performance enthusiasts and even overclockers, and the noise level is quite modest. In many systems, the Panaflo even at 12V is not much of a noise hardship. There is a touch of whine, but overall, the sound is smooth and easy on the ear.
2) With the Panaflo at 9V, performance remains fine. It is roughly on par with the performance of the stock fan at the borderline 1600 RPM setting. The noise is substantially lower (by 3 dBA) and smoother, with less buzz or hum. This is probably quiet enough for lots of PC silencers.
3) With the Panaflo at 7V, noise drops down to about inaudible in most systems and most environments. It can be heard if you get close enough. There is a bit of hum, and maybe a touch of chuffing, but both are at very low levels. You have to work to hear them, Inside most PCs, with all the other noise makers, it would be masked most of the time. Cooling performance is probably not good enough for most users with this CPU, however. A cooler CPU would make the 7V Panaflo a more viable option with the FCS-50.
4) DUAL 7V Panaflos in Push-Pull
It just had to be tried. The results were not great, however. As you can see in the table below, two Panaflos at 7V in push-pull are not as effective as a single Panaflo at 9V, and it’s even noisier. The Bottom Line: Push-pull is probably more useful where there is greater impedance and the airflow needed is higher than is usually used for silent computing.
| PANAFLO 80L | Idle temp* | Max temp* | Temp rise* | °C/W TDP | °C/W MP | Noise** |
| one, 7V | 45 | 59 | 37 | 0.54 | 0.47 | 17 |
| two, 7V; in push-pull | 43 | 52 | 30 | 0.43 | 0.38 | 20 |
| one, 9V | 41 | 51 | 29 | 0.32 | 0.37 | 19 |
| * Idle, Max and Temp rise figures all in °C. ** Noise of fan on HS in free air, in dBA @ 1m distance. TDP (Thermal Design Power of CPU) = 69W MP (Maximum Power of CPU) = 79W | ||||||
VERSUS COMPETITORS
A quick comparison with the Temperature Rise Over Ambient (in °C) of other HS tested on this motherboard and CPU with the Panaflo fan:
| PANAFLO 80L | Scythe FCS-50 | Thermalright SP97 | Thermalright SP900U | Zalman 7000AlCu* |
| 12V | 23 | 24 | 24 | – |
| 9V | 29 | 28 | 27 | 27 |
| 7V | 37 | 35 | 36 | – |
| * Because the Zalman uses an integrated 92mm fan, it was matched to the same of similar noise level: At 5V, the Zalman produces ~20 dBA/1m, 1 dBA higher than the Panaflo 80L at 9V | ||||
It is a very close race. You might even consider the results within the margin of error of the test system or of manufacturing variances among the products. However, there is one important thing to consider:
A system that incorporates the Scythe FCS-50 (mounted so that its fan is blowing towards the back) will have the added benefit of having much of the hot air from the CPU be evacuated from the case by the case fan directly in line with the heatsink exhaust air. This could make a very sizable difference (probably several degrees at least) in the actual in-system temperatures that can be achieved with the FCS-50 compared to the Thermalrights and the Zalmans, which all blow down and spread the exhaust heat from heatsink all around.
Keep in mind that at max stock fan speed, the FCS-50 is ~15 dBA louder than the Zalman 7000 with its integrated fan at full blast, and achieves only similar cooling (50 dBA / 17°C rise Vs. 37 dBA / 17°C rise).
Here’s an interesting thought: The AOpen XC Cube EZ65 has a HS retention bracket that’s rotated the right way for this HS and with some hacking to the drive tray, the FCS-50 might just fit. If it does, that’d be one heck of a cooling solution for those who want super quiet with a hot CPU in the AOpen rig.
FINAL CONCLUSIONS
The Scythe FCS-50 is the most effective cooler they have produced thus far. In stock form with its extraordinarily wide-speed fan and controller, the performance of the FCS-50 ranges from extremely powerful cooling and high noise to very quiet but somewhat marginal cooling. Many users will be able to find a position on the speed dial that provides a nice balance between cooling and low noise, even with hot processors and systems.
The potential to exhaust the hot air from the CPU / heatsink straight out the back panel case fan is highly attractive. This setup is definitely worth a try, but to be honest, I have run out of steam to continue testing here. Perhaps in a postscript when the heatwave in Vancouver subsides.
The FCS-50 stands apart from other recent heatsinks of similar tower / flow-through style in that it’s much better thought out. The weight is not ridiculously high, and the stock fan is pretty good in its acoustic qualities when kept under the bottom half of the speed control. It’s too bad that the HS cannot be rotated 90 degrees by the user, although given the basic structure, this might be a serious challenge.
Pros * Great basic design
* Highly versatile secure mounting
* Very high cooling performance
* Flexible fan options
* Pretty good versatile stock fan
* Nice fan speed control
* Flow-through fan config can allow for improve system cooling
* Stock fan can be very quietCons * High weight, although mostly in base
* Cost?
* Cannot be rotated for different socket orientations
* Stock fan too loud at max
Much thanks to Scythe Japan and Scythe-USA for the FCS-50 sample.
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