July 7, 2003 by Mike Chin
| Product | Arctic Cooling Super Silent 4 TC |
| Manufacturer / Supplier | Arctic Cooling / Silicon Valley Compucycle (SVC) |
| Selling Price | ~US$20 |
Thermally-controlled CPU coolers are more common than ever before. It’s a simple concept: Tie the speed of the fan to the temperature of the CPU. The hotter the CPU gets, the faster the fan spins. The benefit is reduced noise without sacrificing cooling. You may already know that Intel’s stock P4 coolers use thermal fan speed control (see the sidebar “Intel thermal control fan: At what temp?“), though it is not really used to keep the fan quiet.
In theory, thermally-controlled CPU coolers sound really good, but in practise, details such as the noise quality of the fan at low speeds, the temperature vs. fan speed curve, the location of the fan speed thermistor, and the quality and design of the heatsink itself all have to come together to make a cooler that performs well quietly.
Arctic Cooling’s Super Silent Pro TC heatsink fan for socket-A (AMD) was reviewed in SPCR’s first article on thermally-controlled coolers. The Arctic Cooling Super Silent 4 Pro TC for Pentirum 4-478 socket CPUs bears a strong family resemblance to that earlier product. The Super Silent 4 Pro TC is a brand new product that is not featured yet on the Arctic Cooling web site at time of writing. It is their second generation temperature controlled cooler for P4-478.
For the record, the obligatory product packaging shot:
It is a cardboard box just slightly larger than the HSF, containing the HSF, a small tube of silicone heatsink compound (said to contain 30% metal oxide), and a brief note explaining that
“At low temperatures the fan runs either not continuously or very slowly. For the CPU this is not a problem at all, since the cold heatsink even without a fan running is sufficient to keep it cool.”
They must have received complaints of alarm for this note to be included.
Manufacturer’s Specifications
| Recommended CPUs | Intel Pentium 4 up to 3.06 GHz; Intel Celeron up to 3.06 GHz |
| Heat Sink Dimensions | 94 (l) x 76 (w) x 40 (h) mm |
| Fan Dimensions | 80 (l) x 80 (w) x 73 (h) mm |
| Overall Dimensions | 97 (l) x 115(w) x 78 (h) mm |
| Fan Speed | 1400 – 2800 RPM |
| Power | 12V, 0.18A |
| Air flow | 14 – 36 CFM |
| Noise | 12 – 23 dB |
| Thermal Resistance | 0.18° C / W |
One attribute not covered by the specs is weight, which is around 450 grams.
A clearly visible difference (compared to their last gen SS4TC) is the design of the fan. The frame around the blades has been reduced to a minmum, and the bearing housing is unusually tall. As other designs such as the Zalman 7000 have shown, minimizing the fan frame can reduce turbulence losses in airflow and improve cooling. It can also reduce noise.
The fan, its interface to the heatsink, and the mounting clips for the HSF are all integrated neatly into a one-piece mostly plastic assembly. It is clipped tightly to the heatsink via 4 plastic tabs that catch on a lip on the outermost fins. there are also 4 resilient pads between the top of the HS fins and the plastic fan / clip assembly. These are said to provide noise / vibration reduction, but the improvement can only be marginal because the HSF assembly is clamped tightly together when installed on a CPU.
The basic heatsink itself is a chunky block of aluminum with a thick base and 28 fins. It is a bit larger than the standard Intel P4 HS, and about 20% taller as well. The base is flat well finished but has visible lines that can be felt with the fingernails. (It is, however, difficult to capture in a low-pixel image.) Lapping would probably improve performance.
A thermistor at the end of a short pair of leads is wedged in the center of the fins as shown above. The same arrangement was used in Arctric Cooling’s earlier socket-A HS.
Also visible in the above photo are the mounting clips. The two visible clips are hinged hooks at the end of an encapsulated steel tension spring, probably like those used on conventional socket-A / 370 heatsinks. There are two such tension springs for the 4 hooks. Large plastic handled finger tabs make mounting and removing the HSF a cinch: Place the HS atop the CPU, hinge a clip outwards while pressing down, then hinge the clip back to engage the square hole in the retention frame. Engaging clips on opposite corners seemed to be the most expedient method.
Another nice detail is the 3-pin fan lead with RPM monitoring, which is protected by a tidy webbing sleeve. It is 8″ (20 cm) long: not so long to be a bother and long enough to reach the appropriate 3-pin header on any motherboard. Well thought out. The fan blows down on the HS, by the way.
TESTING
The integrated fan and thermal fan speed controller in the Arctic Cooling Super Silent 4 Pro TC does not allow the use of our standard heatsink testing method of a Panaflo 80L (80mm low speed fan) at 12, 7 and 5 volts. (This procedure allows heatsinks to be compared directly without the variable of different fan airflow / noise.) Instead, the SS4ProTC was tested as an integrated HSF.
P4 HS Testing Platform
Key Components
Intel P4-2.53 Nominal power is 61.5W; may increase to ~75W if speed throttling doesn’t stop it first. 71° C rated maximum junction temp. We’ll pull the plug if any HS let’s the temp go much above 65° C. NOTE: Recently upgraded from P4-1.8A CPU.
Intel D845PEBT2 motherboard – Intel 845PE Chipset; on-die thermal diode monitoring
Panaflo FBA08A12L1A 80mm DC fan and/or stock fan supplied with HS
Any VGA card (AGP)
256 MB DDRAM – PC2100 generic
Any hard drive (in Smart Drive from Silicon Acoustics)
DigiDoc5 w/ thermal sensors
Any Good PSU
Zalman Multi-Connector (ZM-MC1)
Arctic Silver 3 Thermal Compound – Arctic Silver is widely regarded as the best thermal compound available. The Arctic Silver people provide detailed instructions on how to get the best of their product, and these instructions are adhered to religiously. Except for one point: They caution that it…
“…will take a minimum of 72 hours, and as many as 200 hours to achieve maximum particle to particle thermal conduction and for the heatsink to CPU interface to reach maximum conductivity. (This period will be longer in a system without a fan on the heatsink.) The CPU’s temperature will drop as much as 2C to 5C over this “break-in” period.”
We just can’t afford that kind of time, so measurements are usually taken anywhere from half an hour to a couple of hours after application. Slap our wrists and subtract 2C from all our temp readings if you wish.
CPUBurn is the stress program used to load the CPU to 100%. It heats up the CPU a bit more than just about any other utility tried so far.
TEST RESULTS
Real world conditions are tougher in some ways than those in the SPCR lab. This is certainly true regarding system ventilation. When a system is installed in a PC case, the ambient temperature is sure to rise at least 5° C, more often 10° C or even more, depending on particulars. Many quiet PC enthusiasts run systems with no case fan or just one low airflow fan.
In consideration of these factors, low noise enthusiasts are urged to add 10° C to the test results when trying to guesstimate what their temperatures would be. Even better would be to measure the in-case temperature near the HS fan and use the C/W figures to calculate likely CPU temperatures.
Keep in mind, however, that long-term CPU load testing is an artificial and stressful test. Some users may never subject their PCs to such loads.
In any case, it is best to regard the test results not in an absolute way, but rather, as comparative guidelines. The result obtained with this heatsinks will vary greatly on the particulars for each system.
- All temperatures in degrees Celsius.
- CPU: Temp reading from CPU thermal diode, recorded by Intel Active Monitor.
- Ambient temperature was 24° C throughout the testing. This is the average of temps measured at several points ~2 feet distance around the test platform.
| 20+ min. CPUBurn Test: Arctic Cooling SS 4 Pro TC | ||||
| P4-2.53 (61.5W) | Idle | Max Load | Temp Rise | ° C/W |
| CPU Temp | 32° C | 51° C | 27° C | 0.44 |
| Fan RPM | 440 | 1900 | – | – |
Noise
The explanatory note included in the Arctic Cooling SS 4 Pro TC package (discussed at the beginning of this review) is there for a good reason. When the system was first turned on after being off for about 10 minutes, the fan spun up for a few seconds, then stopped completely. It turned on / off for a minute or so before spinning steadily. At the recorded 440 RPM, the fan is extremely quiet. It is comparable to a Panaflo 80L at around 5-6V. It buzzes more than the Panaflo, but the level is so low that this is probably irrelevant except for total silence seekers. Other components in most systems will surely swamp this noise.
The fan stabilized at 1900 RPM after about 15 minutes of CPUBurn. The CPU temperature reached 51° C and stayed there. At this speed, the noise was about the same as a Panaflo 80L running at 10V. Clearly audible, but not unpleasant, with no whine or nasty side effects other than some buzzing beneath the whooshing wind turbulence.
Removing the CPU load had a immediate effect on the fan. Its speed dropped quickly in a matter of a minute or two to about 1300 RPM. The relationship between CPU and fan speed was recorded; it is shown in the table below.
| CPU ° C | 32 | 45 | 47 | 48 | 49 | 50 | 51 | 55* | 60* |
| Fan RPM | 440 | 1300 | 1400 | 1600 | 1700 | 1800 | 1900 | 2150* | 2500* |
*The last two measurements were made with the aid of small cardbox box to completely enclose the motherboard. The box trapped the heat of the CPU and board to raise the overall temperature. This was done to determine whether the fan has any headroom to speed up and provide more cooling for hotter CPU loads. Obviously, it does.
NOTE, that the CPU vs fan speed relationship suggested by the table is influenced by another factor: The immediate ambient temperature around the HSF. In other words, the thermistor that controls the fan speed is affected not only by CPU heat but also the air temperature surrounding the HSF. Case temperature, in real applications. As the photo below shows, the temperature in the cardbox box reached 38° C. (The sensor was pushed through the a small hole punched in the box; the black wire leads to the sensor.)
It was difficult to assess the noise at these higher RPM levels. Taking the box off to listen to the fan had the effect of immediately reducing the temp, which led to an almost immediate drop in fan speed. It is safe to say that at 2150 RPM, the SS4ProTC makes more noise than a Panaflo 80L at 12V. The noise is primary wind turbulence — the whoosh of the fan blades. There is no whine; the Panaflo may actually have a touch more. At 2500 RPM, about the maximum rated speed of this fan, it is naturally louder yet again, and the pitch of the noise is higher. It’s still not a whine, though.
Cooling Performance
A 27° C temperature rise or 0.44° C/W is not exactly record setting performance, but it is certainly good enough for the P4-2.53 in the test environment. That phrase — good enough — is a key to understanding how this HSF works: The fan only spins up as much as necessary.
The difficulty with assessing this HS is the question of whether the 0.44° C/W remains valid for hotter CPUs. If so, then the fan will not increase speed and the temp will go higher for hotter CPUs. But the cardbox box results above suggest that the fan speed may increase and the C/W improve.
It was a question interesting enough to warrant another test. A P4-2.8, which has a power dissipation rating of 68.4W, was swapped into the test platform and the CPU load test run again.
| Arctic Cooling Super Silent 4 Pro TC– Ambient: 24° C | ||||
| P4-2.8 (68.4W) | Idle | Max Load | Temp Rise | ° C/W |
| CPU Temp | 37° C | 55° C | 31° C | 0.45 |
| Fan RPM | 700 | 1900 | – | – |
At the room ambient of 24° C, the max fan speed did not increase going from a heat load of 61.5W to 68.4W. The ° C/W remained unchanged. There is likely a lag between CPU core temperature and the temperature registered by the thermistor in the HS fins. One would expect that in the confines of a case, the higher air temperature would push the thermistor to higher temps and the fan to higher speeds — as in the cardbox box results.
CONCLUSIONS
The Arctic Cooling Super Silent 4 Pro TC is a wonderful exercise in engineering efficiency. Few HSF packages boast such cleverness and simplicity in design, while also being inexpensive and well manufactured. The mounting system is so simple to use, secure and positive. The temperature / fan speed curve is very cannily selected to provide low noise operation without unduly compromising cooling capacity. Then there’s attention to details like the perfect length 3-pin fan lead protected by the tidy webbing sleeve.
No, it is definitely not a high end cooler, it doesn’t have flawless machining and polish, and it does not contain even one gram of copper. The fan is also not quite a match for our reference Panaflo. Yet this unassuming HS can probably provide very quiet cooling for most P4 systems most of the time.
Given the anticipated sub-US$25 pricing of the SS4ProTC and good but modest cooling performance, its most likely role is a drop-in quiet replacement for stock Intel P4 HSFs. It is certainly much quieter than any stock Intel P4 HSF I’ve encountered thus far, and the price is attractive.
If you have a hot CPU in a system with hot components, the Arctic Cooling SS4ProTC probably will not give the cooling power you need, and it may not stay quiet. Just about any P4 model in SPCR’s Recommended HS list will outperform the SS4ProTC — albeit at a higher price and greater complexity. The Arctic Cooling SS4ProTC is ideal for users who don’t need cutting-edge performance and want things to be simple: This cooler will provide perfectly good performance and eliminate the HSF as a significant source of PC noise.
Our thanks to Arctic Cooling and to Silicon Valley Compucycle for their kind support.
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