Introduction

The Zalman FX100 is a fanless CPU cooler with a huge cube heatsink and 10 heatpipes. Let’s test it with no fan, and also with one optional 92 mm fan, and see if it can cool our CPU. Check it out!

Although being advertised as a truly fanless CPU cooler, Zalman says that the use of an optional 92 mm fan is required when used with a socket LGA1366 or socket LGA2011 CPU. Actually, the product documentation says that it supports CPUs with a TDP up to 130 W when a fan is used, but there is no information about how many watts the FX100 supports in fanless operation.

Figure 1 shows the huge box of the FX100.

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Figure 1: Package

Figure 2 shows the contents of the box: the cooler, a small bag of thermal compound, a manual, and installation hardware. This cooler does not come with any fan.

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Figure 2: Accessories

Figure 3 displays the front of the cooler.

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Figure 3: Front view

This cooler is discussed in detail in the following pages.

The Zalman FX100

Figure 4 illustrates the side of the Zalman FX100. Here you can see the curves of the heatpipes.

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Figure 4: Side view

Figure 5 reveals the rear of the cooler. Notice that there are actually four heatpipes going through the base.

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Figure 5: Rear view

Figure 6 shows a top view of the cooler, which is closed by a removable meshed plate.

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Figure 6: Top view

Figure 7 unveils the bottom of the cooler. Two heatpipes go for the corners of the heatsink and two enter in the middle, where there are two independent heatsinks.

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Figure 7: Bottom view

The Zalman FX100 (Cont’d)

Figure 8 shows the base of the cooler. It is a nickel-plated copper plate with mirrored finishing.

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Figure 8: Base

Removing the top cap, you can obtain a better idea of how the FX100 is made; there are four heatsinks at the sides, and two smaller heatsinks at the center. The optional fan goes between the inner heatsinks.

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Figure 9: Cover removed

Figure 10 unveils the FX100 without the plastic corners. Here you can see the six heatpipes that surround the cooler. Those heatpipes are soldered to the heatpipes that come from the base.

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Figure 10: Corners removed

Installation

Figure 11 shows the backplate for use with AMD and Intel processors, except for socket LGA2011 CPUs, with the nuts installed.

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Figure 11: Backplate

Install the backplate on the solder side of the motherboard, and then the four spacers on the component side. Then place the two metal bars shown in Figure 12, holding them with four thumbnuts.

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Figure 12: Metal bars installed

The next step is a little tricky: you need to remove the cover from the cooler, put the heatsink over the CPU, and hold it in place with a third bar, fastening two screws at the first bars. But this bar and those screws are loose, and you need a very long Phillips screwdriver to fasten them, taking extra care so they do not fall from the holes.

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Figure 13: Heatsink installed

Installation (Cont’d)

After installing the heatsink, put the cover back in place. At the end of the process, it was one of the most annoying mounting systems we ever saw.

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Figure 14: Cover back in place

We tested the FX100 without any fan, and also with a 92 mm fan, which we removed from a Cooler Master Hyper TX3 cooler we had on hand. This fan has 2,800 rpm nominal speed, airflow of 54.8 cfm, 35 dBA of noise level, and 3.12 W power consumption. Figure 15 shows the cooler with the fan installed.

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Figure 15: Fan installed

We detected a little mounting problem with the Zalman FX100: as shown in Figure 16, the transversal bar is too long and touched the heatsinks of the motherboard. The cooler was firmly installed, but it may have lost a little pressure because of this problem.

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Figure 16: Mounting problem

How we tested

We tested the cooler with a Core i5-2500K CPU (quad-core, 3.3 GHz), which is a socket LGA1155 processor with a 95 W TDP (Thermal Design Power). In order to get higher thermal dissipation, we overclocked it to 4.0 GHz (100 MHz base clock and x40 multiplier), with 1.3 V core voltage (Vcore). This CPU was able to reach 4.8 GHz with its default core voltage, but at this setting, the processor enters thermal throttling when using mainstream coolers, reducing the clock and thus the thermal dissipation. This could interfere with the temperature readings, so we chose to maintain a moderate overclocking.

We measured noise and temperature with the CPU under full load. In order to get 100% CPU usage in all cores, we ran Prime 95 25.11 with the “In-place Large FFTs” option. (In this version, the software uses all available threads.)

We compared the tested cooler to other coolers we already tested, and to the stock cooler that comes with the Core i5-2500K CPU. Note that the results cannot be compared to measures taken on a different hardware configuration, so we retested some “old” coolers with this new methodology. This means you can find different values in older reviews than the values you will read on the next page. Every cooler was tested with the thermal compound that comes with it.

Room temperature measurements were taken with a digital thermometer. The core temperature was read with the SpeedFan program (available from the CPU thermal sensors), using an arithmetic average of the core temperature readings.

During the tests, the panels of the computer case were closed. The front and rear case fans were spinning at minimum speed in order to simulate the “normal” cooler use on a well-ventilated case. We assume that is the common setup used by a cooling enthusiast or overclocker.

The sound pressure level (SPL) was measured with a digital noise meter, with its sensor placed near the top opening of the case. This measurement is only for comparison purposes, because a precise SPL measurement needs to be made inside an acoustically insulated room with no other noise sources, which is not the case here.

Hardware Configuration

• Processor: Core i5-2500K
• Motherboard: ASUS Maximus IV Extreme-Z
• Memory: 16 GB G.Skill Sniper (DDR3-1600/PC3-12800), configured at 1,600 MHz
• Hard disk: Seagate Barracuda XT 2 TB
• Video card: Point of View GeForce GTX 460 1 GB
• Video resolution: 1920x1080
• Video monitor: Samsung SyncMaster P2470HN
• Power supply: Seventeam ST-550P-AM
• Case: Cooler Master HAF 922

Operating System Configuration

• Windows 7 Home Premium 64 bit SP1

Software Used

• Prime95
• SpeedFan

Error Margin

We adopted a 2°C error margin, meaning temperature differences below 2°C are considered irrelevant.

Our Tests

The table below presents the results of our measurements. We repeated the same test on all coolers listed below. Each measurement was taken with the CPU at full load. In the models with a fan supporting PWM, the motherboard controlled the fan speed according to core load and temperature. On coolers with an integrated fan controller, the fan was set at the full speed.

Cooler	Room Temp.	Noise	Speed	Core Temp.	Temp. Diff.
Cooler Master Hyper TX3	18 °C	50 dBA	2850 rpm	69 ºC	51 °C
Corsair A70	23 °C	51 dBA	2000 rpm	66 ºC	43 °C
Corsair H100	26 °C	62 dBA	2000 rpm	64 ºC	38 °C
EVGA Superclock	26 °C	57 dBA	2550 rpm	67 ºC	41 °C
NZXT HAVIK 140	20 °C	46 dBA	1250 rpm	65 ºC	45 °C
Thermalright True Spirit 120	26 °C	42 dBA	1500 rpm	82 °C	56 °C
Zalman CNPS12X	26 °C	43 dBA	1200 rpm	71 °C	45 °C
Zalman CNPS9900 Max	20 °C	51 dBA	1700 rpm	62 °C	42 °C
Titan Fenrir Siberia Edition	22 °C	50 dBA	2400 rpm	65 °C	43 °C
SilenX EFZ-120HA5	18 °C	44 dBA	1500 rpm	70 °C	52 °C
Noctua NH-L12	20 °C	44 dBA	1450 rpm	70 °C	50 °C
Zalman CNPS8900 Extreme	21 °C	53 dBA	2550 rpm	71 °C	50 °C
Gamer Storm Assassin	15 °C	48 dBA	1450 rpm	58 °C	43 °C
Deepcool Gammaxx 400	15 °C	44 dBA	1500 rpm	60 °C	45 °C
Cooler Master TPC 812	23 °C	51 dBA	2350 rpm	66 °C	43 °C
Deepcool Gammaxx 300	18 °C	43 dBA	1650 rpm	74 °C	56 °C
Intel stock cooler	18 °C	41 dBA	2000 rpm	97 °C	79 °C
Xigmatek Praeton	19 °C	52 dBA	2900 rpm	83 °C	64 °C
Noctua NH-U12P SE2	18 °C	42 dBA	1300 rpm	69 °C	51 °C
Deepcool Frostwin	24 °C	46 dBA	1650 rpm	78 °C	54 °C
Thermaltake Frio Advanced	13 °C	56 dBA	2000 rpm	62 °C	49 °C
Xigmatek Dark Knight Night Hawk Edition	9 °C	48 dBA	2100 rpm	53 °C	44 °C
Thermaltake Frio Extreme	21 °C	53 dBA	1750 rpm	59 °C	38 °C
Noctua NH-U9B SE2	12 °C	44 dBA	1700 rpm	64 °C	52 °C
Thermaltake WATER2.0 Pro	15 °C	54 dBA	2000 rpm	52 °C	37 °C
Deepcool Fiend Shark	18 °C	45 dBA	1500 rpm	74 °C	56 °C
Arctic Freezer i30	13 °C	42 dBA	1350 rpm	63 °C	50 °C
Spire TME III	8 °C	46 dBA	1700 rpm	70 °C	62 °C
Thermaltake WATER2.0 Performer	11 °C	54 dBA	2000 rpm	49 °C	38 °C
Arctic Alpine 11 PLUS	11 °C	45 dBA	2000 rpm	82 °C	71 °C
be quiet! Dark Rock 2	10 °C	41 dBA	1300 rpm	58 °C	48 °C
Phanteks PH-TC14CS	16 °C	47 dBA	1300 rpm	58 °C	42 °C
Phanteks PH-TC14PE	16 °C	48 dBA	1300 rpm	57 °C	41 °C
SilverStone HE01 (Q)	19 °C	44 dBA	1150 rpm	63 °C	44 °C
SilverStone HE01 (P)	20 °C	57 dBA	2050 rpm	62 °C	42 °C
Thermaltake WATER2.0 Extreme (S)	17 °C	44 dBA	1250 rpm	52 °C	35 °C
Thermaltake WATER2.0 Extreme (E)	17 °C	53 dBA	1900 rpm	50 °C	33 °C
Deepcool Neptwin	11 °C	46 dBA	1500 rpm	56 °C	45 °C
SilverStone HE02	19 °C	49 dBA	2000 rpm	64 °C	45 °C
Zalman CNPS9900DF	23 °C	45 dBA	1400 rpm	68 °C	45 °C
Deepcool ICE BLADE PRO V2.0	22 °C	43 dBA	1500 rpm	67 °C	45 °C
Phanteks PH-TC90LS	24 °C	47 dBA	2600 rpm	95 °C	71 °C
Rosewill AIOLOS	20 °C	40 dBA	1600 rpm	94 °C	74 °C
Corsair H60	20 °C	49 dBA	2000 rpm	64 °C	44 °C
Zalman LQ310	27 °C	51 dBA	2050 rpm	65 °C	38 °C
Noctua NH-L9i	24 °C	44 dBA	2500 rpm	95 °C	71 °C
NZXT Respire T40	20 °C	45 dBA	1850 rpm	76 °C	56 °C
NZXT Respire T20	21 °C	45 dBA	1900 rpm	77 °C	56 °C
Zalman LQ315	20 °C	52 dBA	1950 rpm	57 °C	37 °C
Corsair H80i (Quiet)	19 °C	44 dBA	1100 rpm	61 °C	42 °C
Corsair H80i (Maximum)	19 °C	57 dBA	2500 rpm	55 °C	36 °C
NZXT Kraken X40 (Silent)	25 °C	44 dBA	1050 rpm	66 °C	41 °C
NZXT Kraken X40 (Extreme)	25 °C	53 dBA	1650 rpm	62 °C	37 °C
Zalman LQ320	20 °C	52 dBA	2100 rpm	57 °C	37 °C
Corsair H100i (Quiet)	22 °C	45 dBA	1150 rpm	58 °C	36 °C
Corsair H100i (Maximum)	22 °C	61 dBA	2500 rpm	54 °C	32 °C
NZXT Kraken X60 (Silent)	26 °C	46 dBA	1000 rpm	62 °C	36 °C
NZXT Kraken X60 (Extreme)	26 °C	60 dBA	1650 rpm	60 °C	34 °C
Prolimatech Genesis Black Series	25 °C	46 dBA	1150 rpm	69 °C	44 °C
Phanteks PH-TC12DX	25 °C	51 dBA	1850 rpm	74 °C	49 °C
Corsair H90	23 °C	51 dBA	1550 rpm	61 °C	38 °C
Corsair H110	27 °C	58 dBA	1500 rpm	60 °C	33 °C
Evercool Venti	23 °C	49 dBA	2250 rpm	72 °C	49 °C
Thermalright Archon SB-E X2	22 °C	45 dBA	1400 rpm	68 °C	46 °C
Scythe Kabuto II	20 °C	41 dBA	1450 rpm	67 °C	47 °C
Prolimatech Megahalems Red Series	20 °C	51 dBA	1500 rpm	63 °C	43 °C
Zalman FX100 (fanless)	18 °C	NA	NA	98 °C	80 °C
Zalman FX100 (92 mm fan)	18 °C	50 DBA	2850 rpm	69 °C	51 °C

In the graph below, you can see how many degrees Celsius hotter the CPU core is than the air outside the case. The lower this difference, the better is the performance of the cooler.

In the graph below, you can see how many decibels of noise each cooler makes.

Main Specifications

The main specifications for the Zalman FX100 CPU cooler include:

• Application: Sockets AM2(+), AM3(+), FM1, FM2, LGA775, LGA1155, LGA1156, LGA1366, and LGA2011
• Dimensions: 6.1 x 6.1 x 6.2 inches (156 x 156 x 157 mm) (W x L x H)
• Fins: Aluminum
• Base: Nickel-plated copper
• Heat-pipes: Ten 6 mm copper heatpipes
• Fans: Optional 92 mm fan (not included)
• Nominal fan speed: NA
• Fan air flow: NA
• Power consumption: NA
• Nominal noise level: NA
• Weight: 1.78 lb (790 g)
• More information: http://www.zalman.com
• MSRP in the U.S.: USD 85.00

Conclusions

After testing the Zalman FX100, one thing seems to be clear to us: there is no fanless cooler capable of cooling a high-end CPU, especially if it is overclocked. Even with all its size, the FX100 showed a barely reasonable cooling performance with a noisy fan installed.

Mounted with no fan, the FX100 didn’t handle our CPU, even considering it has a very light overclocking and that there was a case exhaust fan at the rear panel, very close to the cooler. The CPU reached the temperature limit and throttled down the clock. Maybe it can cool a low-TDP processor, but it seems pointless to install such a huge cooler if even the stock cooler cools the CPU better, with a very low noise level.

The Zalman FX100 was a complete disappointment. It may have a stunning look, but the installation system and the cooling performance have much to be improved.