BlueSmoke - Review : Copper Heatsink/Fan Roundup

		Date	: Aug 22nd, 2001
		Category	: Cooling
		Manufacturer	: Various
		Author	: Jin-Wei Tioh

More and more manufacturers are using copper in their heatsinks, either as an inlay, for the base plate or even for the entire cooler. In theory, copper is a better thermal conductor than aluminum. But don't go gaga just yet, as the efficiency of the manufacturer's design also weighs in heavily in the cooler's performance. An efficient aluminum or copper-aluminum hybrid design could easily outperform an inefficient copper design. With non-retail boxed or "loose tray" CPUs, DIY PC assembly and the ever increasing power dissipation of the latest CPUs, more end-users are fast becoming aware of this critical system component. The days when end-users had only a handful (literally) of coolers to chose from are long over; the number of manufacturers and their corresponding products are mind-boggling. Don't believe us? Just take a peep at our Sponsors section.

The coolers in this copper roundup are the : Blizzard S370, GlobalWIN CAK-38, Spire 5P53B3, Thermalright SK6, Thermaltake Mini Copper Orb and Zalman CNPS 5000 Plus. We would like to take a moment to thank all the sponsors that have made this roundup possible. The Blizzard was supplied by Blizzard Heatsinks; the CAK-38 by 2CoolTek; the Spire 5P53B3 by ByteCom Fanner B.V.; the SK6 by Thermalright; the Mini Copper Orb by Thermaltake; and the CNPS 5000 Plus by Zalman. Please keep in mind that even though some heatsinks were supplied directly from the manufacturers, there is no bias in this article. Without further ado, let's see the results of the performance test.

These graphs show the temperature delta between the CPU case temperature and the intake air temperature. To maximize CPU power dissipation, we ran StabilityTest, HotCPU Lite and the BlueSmoke RC5-64 Client simultaneously under Windows 2000. The test unit basically consisted of an AMD Duron 800, AOpen AK73 Pro (A) (courtesy of AOpen), a S3 Virge PCI sitting in the last PCI slot and the measuring apparatus (courtesy of HighSpeed PC). The unit was setup on an open tabletop, giving the cooler an ideal functioning environment (ie. unobstructed airflow, minimized recycling of hot air). Air turbulence in the room was virtually non-existant, ensuring that only the fan on the heatsink was doing all the work. Other heat sources (eg. lights, monitors) were also minimized to ensure a more accurate determination of performance results. About the only confounding factor is the heat generated by some of the nearby components, eg. RAM, voltage regulators and the north bridge. Lastly, the primary TIM (thermal interface material) used in the evaluations is Arctic Silver II, kindly supplied by Arctic Silver LLC.

This graph shows the thermal resistance (°C/W) for the heatsinks under each condition. °C/W is both a portable & reliable measurement due to it's dependence on only the temperature delta between the CPU case and the intake air. While absolute temperatures may vary from place to place, you would only need a pair of thermometers that agree with each other to obtain a reasonably accurate °C/W value. To calculate the °C/W of a cooling solution :

°C/W = [CPU Temperature (°C) - Intake Air Temperature (°C)] ÷ Watts

The result would usually fall in the range of 0.2 - 1.5, the lower the better as we'll shortly see why. A rough temperature measurement shouldn't be too difficult for anyone, but obtaining the power dissipation for your CPU (Watts) might present some difficulties). Fortunately, Chris Hare has compiled all the necessary information for nearly all CPU types. All fine if your CPU is running at stock speed and voltage. But what if you overclocked it? No problem, just use :

OC'ed Power (Watts) = Stock Power (Watts) * [(OC'ed Speed (MHz) ÷ Stock Speed (MHz)) * (OC'ed Voltage ÷ Stock Voltage)^2)]

The lower the °C/W, the better? Given the °C/W for a heatsink/fan, you can calculate how well it should work in your system via the following formula :

CPU Temperature (100% Load) = Intake Air Temperature + (°C/W x Watts)

Thus, the Thermalright SK6 with Arctic Silver II, having a °C/W of 0.28 would keep say a Thunderbird 1.4GHz (72W) at 20.16°C above intake air temperature under 100% load conditions.

This is one cooler that you don't see many sites covering. Blizzard Heatsinks slipped us a mickey with the Blizzard S370, a conventional looking, "old skool" pure copper cooler. It turned in an excellent showing, virtually tying with the Zalman CNPS 5000 Plus and nipping at the heels of the GlobalWIN CAK-38 in stock configuration. The heatsink consists of 16 fins, which have 10 pins each. Unlike the Kanie Hedgehog, the fins are pressed in and welded, in order to ensure more effective heat transfer. The machined base is a nice piece of work, with the mating surface being flat, smooth and even.

The stock fan spins at 4600 RPM (drawing 0.17A)and is a 25x60x60mm (HxWxD) Sanyo Denki unit. Currently, we don't have the necessary equipment to scientifically measure noise levels, but the stock fan is subjectively quieter than a standard YS Tech fan. Obviously, this changed when we slapped on a Delta 7K RPM fan. Granted, the performance of the Blizzard S370 did improve, but the stock fan itself already turns in impressive figures at lower noise levels.

The Blizzard S370's clip uses 2 of the motherboard socket's hooks for support on one side, and 3 on the other. The soft clamps makes installation and removal child's play, no tools required. Motherboard compatibility is high, due to the compact dimensions (WxD) of the S370. Problems might only arise if the end-user intends to use this heatsink/fan unit on a slotket. On a final note, copper heatsink/fan units are usually heavier than their aluminum counterparts. The same goes for the S370, with the heatsink weighing in a 380g. Keep this point in mind when moving your PC around.

The Blizzard S370 costs US$58, which sounds steep until you consider that this already includes shipping charges. The only place where you can get it is directly from Blizzard Heatsinks. A heatsink/fan unit with excellent performance and construction quality which should definitely be on your shortlist.

Blizzard Heatsinks S370
Fan	: Sanyo Denki Pico Ace 25 - 4600 RPM - 25x60x60mm (HxWxD)
Dimensions	: 45x60x60mm (HxWxD)
Weight	: 380g (w/o fan)
Price	: US$58 (incl. shipping)
Available	: Blizzard Heatsinks

The CAK-38 is GlobalWIN's all copper offering, which is akin to a quantum leap for them. Previously, GlobalWIN had only made aluminum coolers , not even bothering with copper inlays when the copper bug began biting many moons ago. Like the Blizzard S370, the CAK-38 has a conventional looking design. The heatsink consists of 23 fins, which have 6 large pins each. The biggest difference is that the CAK-38 is an extruded heatsink, which means that it is fashioned from a single section of copper. This would be preferable to soldering, as seams between the heatplate and the fins are eliminated. The base is also nicely done, with only the edges being rounded.

The stock fan is already the best on the market, the famous 25x60x60mm (HxWxD) black-label Delta 7000rpm fan. This makes the CAK-38 anything but quiet, albeit with pack-leading performance in its stock configuration. In an effort to cut down the noise produced by the Delta, the CAK-38 also sports spacers to raise the fan away from the fins. The newer revision of the CAK-38 does away with the spacers, replacing them with a plastic shroud. Both revisions of the CAK-38 come standard with a 60mm fan grill, should any body appendages stray into the high speed blades...

The CAK-38's clip uses a single socket hook on either side for support. GlobalWIN has reworked their clipping mechanism to make more reliable. Although they won't break now, it is still on the weak side. The clip is so tight that you feel like a python crushing its victim (your CPU). Moreover, you would most probably need a screwdriver to install or remove the CAK-38. Motherboard compatibility of the CAK-38 is also high, due to its compact dimensions (WxD). Since this is also a copper heatsink/fan unit, it is going to be heavier than similar aluminum coolers, something you have to consider when moving your PC around.

The CAK-38 will set you back by US$34, not including shipping charges. If you're going to pick one up, you might as well get it from our buddy over at 2CoolTek. A heatsink/fan unit with the best performance in stock configuration (not considering the Thermalright SK6), good construction quality (darn clip...), all at a reasonable price. Jot it down on your shortlist immediately, unless you can't the noise produced by the Delta.

GlobalWIN CAK-38
Fan	: Delta Electronics Black-Label - 7000 RPM - 25x60x60mm (HxWxD)
Dimensions	: 35x60x60mm (HxWxD)
Weight	: 450g (w/o fan)
Price	: US$34 (w/o shipping)
Available	: 2CoolTek

This is another cooler that you don't see on many other sites, if at all. The Spire 5P53B3 is one of ByteCom / FannerTech's entries into the heatsink market. Not only does the 5P53B3 have an unusual name, it has an unusual look as well. It uses an all copper folded fin design - its fins are made out of a copper sheet folder back and forth, welded to the base at the points of contact. This is an easier design, though you sacrifice performance for simplicity. The copper base is also nicely done (though somewhat warped at the edges) and like the rest of the heatsink is super shiny.

Perched on top the shiny copper is an unassuming little 15x55x55mm (HxWxD) ball-bearing fan. Quiet. Doesn't work too well though, landing the 5P53B3 an unexciting 0.67 °C/W. This is not too bad a figure considering the miniscule air flow, and things definitely improved with the Delta fan (0.55 °C/W). Note however that mounting holes are meant for 55x55mm (WxD) fans, so they won't line up with the holes on a 60mm fan.

The clip on the 5P53B3 uses a single socket hook on either side for support. It is easy to install, though not as soft as the clip on the Blizzard S370 and probably not tools free. A flatheaded screwdriver for installation is recommended. Motherboard compatibility is high, due to its compact dimensions (WxD). Slotket users would definitely have no problems with the stock unit, what with its low total height (41.5mm).

Currently, we have yet to see anyone selling the 5P53B3. If you have seen it being sold somewhere, do drop us a line. The 5P53B3 isn't by any means rubbish. It doesn't perform well in stock configuration, but doesn't fare all that badly when paired with a Delta 7000 RPM fan. If you go for looks, it is a swank looking heatsink/fan unit with groovy perforated surround.

Spire 5P53B3
Fan	: Fanner Tech FD05515B1M - 4500 RPM - 15x55x55mm (HxWxD)
Dimensions	: 26.5x63x60mm (HxWxD)
Weight	: 250g (w/o fan)
Price	: N/A
Available	: N/A

The SK6 is Thermalright's all copper heatsink. Thermalright is a relative newcomer in the HSF (heatsink/fan) business, managing to blind-side us. The SK6 is a non-conventional looking design, with 2 banks of 36 thin (though fragile) fins and an ingenious interlocked design that stops them from being bent. This is the yet another heatsink in our roundup that uses a non-extruded design. According to Thermalright, the fins are soldered to the copper heatplate in a vacuum so as to minimize any air gaps that might interfere with heat transfer. The base is a little on the rough side though.

The kit supplied to us was the "bare bones" version which includes everything but a fan. Instead of conventional screws, the SK6 uses a set of wire clips to hold down the fan. Two sets are included : one for 25mm high 60mm fans (like the Delta), and the other for 38mm high 60mm fans. Vendors/retailers sell the SK6 in various configurations, usually bare, with a 4500rpm fan, or with a Delta. We used a black-label Delta and Arctic Silver II to keep everyone on even ground. In this configuration, the SK6 turned heads with the best performance figures (0.28 °C/W). The SK6 uses a standard issue two point clip. It is on the stiff side to install, definitely requiring a screwdriver. Motherboard compatibility might be a more tricky issue in this case, due to the slanted edges which causing the heatsink to have dimensions of 31.6x72x64mm (HxWxD).

The bare SK6 will empty US$34 from your wallet. With a 7000rpm Delta, that figure increases to US$42. This is by no means cheap, given that it's outperformed (price/performance wise) by the lower-priced GlobalWIN CAK-38 (US$34). However the SK6 is a very well engineered piece of hardware with performance that is right on the heels of the leaders in this roundup. If you can afford it, an SK6-based cooler is surely worth a couple of serious looks.

Thermalright SK6
Fan	: N/A
Dimensions	: 31.6x64x72mm (HxWxD)
Weight	: 330g (w/o fan)
Price	: US$34 (bare heatsink w/o shipping)
Available	: 2CoolTek

The Mini Copper Orb from Thermaltake looks pretty much like the Chrome Orb. A peek under the hood reveals that a solid copper slug has been added to the aluminum design. Thus, it is fairly heavier than the old Chrome Orb. The base is also nicely done : all flat, even and smooth. Motherboard compatibility is good due to its compact dimensions : a 65mm diameter and 48mm height. Thermaltake does away with the twist-lock fastening mechanism, infamous for taking out AMD processors. In its place is a built in clip that uses 3 hooks on one end and a single hook on the other. Installation is simple and tools free, but removal is a different animal alltogether. You'll definitely need a flatheaded screwdriver or a pair of needle-nose pliers to do so.

The stock fan spins along at 5500 RPM, delivering an airflow 23.1 CFM while drawing a juicy 0.26A. A little underpowered, which is why it did not fare all that well on our tests. You can "mount" a Delta 7000rpm fan onto it, improving performance by a significant margin. However, this is a rather makeshift solution to the problem.

You can get the Mini Copper Orb for US$19.95 at HighSpeedPC. Rather inexpensive for a cooler with copper in it, plus you get a funky looking heatsink that any modder would be proud to display through his/her case window. Unfortunately, it's not much of a performer, having a 0.5°C/W which is close to that of the Spire 5E34B3 (coming in our next article). A model with a higher flow rate fan is rumored to be coming out soon. In that case, it'll be a great choice for the money.

Thermaltake Mini Copper Orb
Fan	: Thermaltake A5025S12C - 5500 RPM - 25x50x50mm (HxWxD)
Dimensions	: 48x65x65mm (HxWxD)
Weight	: 450g (w/ fan)
Price	: US$19.95 (w/o shipping)
Available	: HighSpeed PC

The Zalman CNPS 5000 Plus is the only Korean entry in this roundup. It uses a more standard fan-on-top design, similar to the "Chinese fan" design of other Zalman coolers except that it is spread over 360°. It consists of thin copper strips pinched together in the middle. One end is machined off to give a flat mating surface, while the other is left as is. Zalman is probably the narcissistic type; they are so much in love with themselves that they stamped their name on every single fin.

Perched on top of the CNPS 5000 Plus is a shroud and fan. CNPS stands for Computer Noise Prevention System, so one could easily guess what is coming next. True to their word, the stock fan isn't that noisy, and Zalman has included two voltage-dropping resistor leads. At full voltage the stock fan does quite well. Dropping the 55 ohm in line decreases the fan's power by 0.67 Watts, and as expected the performance decreased. However, dropping in the 100 ohm lead reduces the fan's voltage to 4.4V, an insufficient voltage for the fan to consistent start rotating. Once you have manually started it going, it spins slowly enough to drive Ms. Daisy. Moreover, the resistors themselves generate some amount of heat, which could be an important consideration in more cramped cases. Slapping on the non-sensical Delta 7000 RPM fan propelled the CNPS to a close second place, just one step behind the Thermalright SK6. Strangely, the Delta seems to produce the most noise on the CNPS, which is something to consider if you already can't stand the noise of the Delta on most other heatsinks.

Looking for a clip? Surprise, the CNPS 5000 Plus uses a bolt-on design, with 2 sets of 4 mounting holes. One set lines up with the cooler retention holes on Pentium IV motherboards, the other with Socket A motherboards. Screw-mount cooler are more troublesome to install than clip-on ones, but are more secure and has the advantage of not wearing out your socket's retention hooks. You cannot install this cooler on a Socket A motherboard without removing it from your case. Some motherboards can't even accept this type of coolers; Zalman has a list of compatible motherboards here. This is either a curse or a blessing; a curse because it's more troublesome to install; a blessing because it can be installed on a motherboard with a damaged CPU socket, so long it has the right mounting holes.

The CNPS 5000 Plus will set you back US$49 at Zalman's online store. In its stock configuration, the CNPS 5000 Plus (at full voltage) turns in respectable scores. Slapping on a Delta brings it up to a close second behind the SK6. This fancy cooler is a good choice if you want something effective yet do not want to live in earmuffs. It's also the salvation for those of you with damaged CPU sockets. If you've got the money (for the CNPS 5000 Plus and a Delta) and want a really nifty looking cooler, this one certainly stands out from the pack.

Zalman CNPS 5000 Plus
Fan	: Zalman GM1206PTBX-AF - 4500 RPM - 25x60x60mm (HxWxD)
Dimensions	: 66x66x70mm (HxWxD)
Weight	: 430g (w/o fan)
Price	: US$49 (w/o shipping)
Available	: Zalman Online Store

So what can one conclude from the hard data? The CAK-38, SK6 and CNPS 5000 Plus are all widely considered to be performance heatsink/fan units and this is definitely reaffirmed from the results presented. The relatively unknown Blizzard S370 falls into this category as well, judging by the °C/W values.It is largely a matter of taste and price in this category, seeing that the difference in performance between the worst and the best contender in stock configurations is only 0.03°C/W and 0.05°C/W when the playing field is leveled with the Delta 7000 RPM fan. The Duron 800 running at 954MHz (1.8v) generates a thermal load of 53.43W, roughly the equivalent of a Thunderbird 1.1GHz. Under this condition, 0.03°C/W would translate into a temperature difference of only 1.6°C, and 0.05°C/W only 2.6°C, hardly a monumental figure.

On the other hand, the Mini Copper Orb and Spire 5P53B3 are not meant to compete with the big boys, but rather positioned to be more "economical" coolers. While lagging behind the top performers by a fair margin, they are by no means junk. The Mini Copper Orb is probably one of the lowest priced heatsink/fan units with copper in it, delivering acceptable performance while managing to look different. The Spire 5P53B3 also looks good with all that shiny copper, but the price/performance issue remains to be seen.

We would like to reiterate that ultimately, it is the °C/W value of a HSF that should be used as a purchasing guide. A 0.03°C/W difference in performance would hardly mean anything on a stock Duron 800, which exerts a thermal load of 35.4W (giving a 1°C temperature difference). Please don't just simply pick the HSF that scored the best. Rather, sit down and take in consideration all the features (aesthetics, noise, availability, etc.) of these coolers and match them to your own specific needs. Overall, all manufacturers are catching up to each other; you can only achieve so much with air cooling. Even assuming a °C/W of 0.2, this means that a 1.4GHz Thunderbird would still be 14.4°C above intake air temperature!

Still, the Thermalright SK6 gets the gold, slight performance delta not withstanding. That said, we doubt that you would be disappointed with any of these products.