by Sergey Lepilov
10/05/2007 | 03:54 PM
How do you measure the performance of an air cooler? In degrees of Celsius or Fahrenheit of the temperature of an overclocked processor? Today, I want to suggest to measure it in a different way, in millimeters! Yes, I’m going to use the measure that is usually applied to the length, width or height of a cooler or the size of its fan, but there is a reason for my doing that. In today’s review I will discuss two coolers that employ heat pipes measuring 8 millimeters in diameter rather than the typical 6mm.
<%BANNER[article]%>There’s nothing new in the idea to use heat pipes with a larger diameter. Early this year we tested the Enzotech Ultra-X cooler that proved to be one of the best air coolers available. The 8mm pipes have a larger area of contact with the base as well as with the heatsink ribs, having a positive effect on the cooler’s overall performance. Of course, the cooler employs fewer pipes than if they were 6 millimeters in diameter. Despite that, the first cooler with 8mm pipes, the Enzotech Ultra-X, proved more efficient than its opponents.
After those tests I thought there would be a migration from 6mm to 8mm heat pipes. And that’s the way it goes now. More and more coolers with lager pipes are being announced these days. Ice Hammer said it would develop such a cooler by the end of 2007 while the yet obscure PC Cooler has already released the South China Sea. For this review I tested two coolers from Thermalright and Xigmatek that use four and three 8mm heat pipes, respectively. Let’s see how efficient these millimeters are.
Thermalright follows a rather ascetic approach to designing packages for its products. No transparent windows, no pretty wrappers or any other decorations. What we have here is a robust cardboard box with a single caption “Thermalright Inc” on its top:
You can find the cooler’s name on a side of the box.
The box is divided into two compartments, the larger of which contains a polyurethane-foam tray for the heatsink.
To the left of it there is a box with accessories that include:
The Thermalright SI-128 is shipped without a fan. The cooler’s heatsink looks like this:
The cooler has four copper nickel-plated pipes, 8mm in diameter, which go out of the cooler’s copper base and carry a large number of thin aluminum plates:
The plates are placed at a distance of less than 1.5mm from each other. This means that increasing the fan speed should have a positive effect on the cooler’s performance. I’ll check this out shortly.
The heatsink is small as today’s coolers go measuring 125x145x91.5mm at 510g of weight. Two wire supports go out of the base opposite the heat pipes to add rigidity to the whole arrangement.
The cooler’s base is finished well:
As you can see, there is no mirror shine here, but the base is perfectly flat.
To enlarge the contact area, the heat pipes lie in grooves made in the base.
I could find no trace of solder or glue, so it’s hard to tell how the contact between the pipes and the base is established. The pipes are covered with an aluminum plate from above, which also serves as a support for the cooler’s fastening mechanism.
You should glue the rubber strips to the heatsink prior to installing the fan – they will reduce vibrations.
The fan is fastened with two wire brackets you insert into the butt-ends of the heatsink.
This is simple and handy, but not quite reliable. The brackets tend to slip off the heatsink. Now that the fan is attached, the Thermalright SI-128 looks whole and imposing:
Two fastening mechanisms are used to mount it on the CPU:
LGA775 | Socket 754/939/940/AM2 |
You don’t have to take the mainboard out of the system case to do that, yet I think this is desirable in order to establish proper contact between the cooler and the CPU heat-spreader. It’s not handy to insert the plastic locks on LGA775 or hitch the clip on K8 platforms when you are doing this inside the system case. Sometimes you don’t even know if the cooler is installed properly or not. So, I recommend to take the mainboard out and do everything in a neat and tidy manner.
The cooler presses hard upon the mainboard which bends under it so heavily that the aluminum heatsink on the power circuit elements of the ASUS P5K Deluxe mainboard touched only two of those elements and I had to insert additional thermal pads in there.
As opposed to the Enzotech Ultra-X, the pipes of the new cooler from Thermalright go out of the base and rise up suddenly. The near-socket elements can’t get in their way. One orientation variant of the cooler was not possible in my system, but only due to the high heatsinks on the memory sticks. I could freely choose from among the other three variants.
The included manual doesn’t indicate the preferable orientation. I installed the cooler in such a way that the ends of the heat pipes were directed upwards.
The recommended price of the Thermalright SI-128 heatsink is $50, and you have to buy a fan to it. Thermalright has also announced a modernized version of the SI-128 with the SE suffix. The new cooler has perforated heatsink ribs. According to the manufacturer, the improved SI-128SE offers less resistance to the airflow from the fan, which allows using slower and quieter fans without losing anything in terms of cooling performance.
The first cooler from Xigmatek we tested in our labs came to us in a plain white cardboard box without any text on it, but we’ve got this one in its retail packaging.
The pretty-looking package has a small cut-out in its front panel to give you a glimpse of the cooler’s 120mm fan. Product features are listed there, particularly the technology of direct contact between the cooler’s heat pipes and the CPU heat-spreader.
A sticker on the reverse side of the box reports detailed product specs to you.
Inside the external box there is another one that holds the cooler’s heatsink and fan.
The accessories lie in the top compartment of the box:
You get the following with the Xigmatek HDT-S1283:
The new cooler has quite an impressive appearance when put together:
With the fan installed it measures 120x80x159mm at a total of 600g of weight.
This seems to be a rather unremarkable design:
A large number of aluminum, almost square, ribs hang on three copper heat pipes. The ribs are curved in on both sides and meet each other partially to make the cooler more rigid.
The ends of the heat pipes are neatly soldered up at the top of the heatsink.
So, everything seems to be typical for a tower-like cooler if it were not for two special features. First, the diameter of the pipes is 8 instead of 6 millimeters. Second, the cooler features Heat-pipe Direct Touch technology for direct contact between the heat pipes and the CPU heat-spreader.
I have tested such tower-like coolers before, but I’ve never seen a cooler with 8mm pipes, direct contact, and with a heatsink for a 120mm fan. In other words, the HDT-S1283 is free from two common drawbacks of other coolers: it has a larger area of contact with the base and a larger heat dissipation area of the heatsink. This is just what the Ice Hammer IH-4050 HP and Xigmatek HDT-S963 needed. Running a little ahead, I should confess both innovations proved their worth.
The cooler’s base is flat, but without traces of polishing.
Note that the pipes are placed at a smaller distance from each other than in the Xigmatek HDT-S963, which should affect the transfer of heat positively.
The cooler comes with a 120mm 7-blade fan with a 4-pin connector:
The fan is marked as “AD1212HX-A7BGL”. Its speed can be varied by means of pulse-width modulation or with the included adapter. The adjustment range is 1000-2200rpm at 20-32dBA of noise. The fan creates airflow of 72.1 to 99.6CFM but the first number is dubious as a 120x25mm fan can hardly do 72.1CFM that at 1000rpm.
The fan is fastened using special grooves in the heatsink. You insert rubber compensators into the fan and then into those grooves.
This reduces vibrations and noise. Moreover, there is a gap (about 3mm in the narrowest point) between the fan and the heatsink – coupled with the concavity of the heatsink on the fan side, this reduces resistance to airflow and puts the latter to better use.
The installation procedure is described in detail in the enclosed manual. The Xigmatek HDT-S1283 is installed fan-less on the CPU – the fan is attached after that. When installing on an LGA775 mainboard, you should secure two fastening clips on the cooler with four plastic locks. On mainboards for AMD’s K8 processors the cooler is installed by means of a pressure clip:
As a result, the new cooler has four possible orientations on LGA775 mainboards but only two on Socket 754/939/940/AM2 mainboards. You don’t have to take your mainboard out of the case whatever platform you deal with.
There is over 40 millimeters from the mainboard to the bottommost plate of the heatsink and the cooler’s base is compact, just like its fastening mechanism. It means the cooler won’t interfere with the mainboard’s around-the-socket components.
Inside a system case the Xigmatek HDT-S1283 doesn’t look a large cooler despite its dimensions:
This cooler will cost you $40-44.
The following table shows the specs and recommended price of the discussed coolers:
* - optional, the heatsink is shipped without a fan
** - the weight is provided without a fan
The new coolers and their opponents were tested on an open testbed as well as in a system case with the following configuration:
There are no weak coolers in this review, so the quad-core CPU with the polished heatspreader lid was overclocked to a very impressive frequency for a B3 Kentsfield core stepping of 3456MHz at a core voltage of 1.6V.
The other mainboard voltages were left default.
All tests are performed in Windows XP Professional Edition Service Pack 2. SpeedFan 4.32 is used to monitor the temperature of the CPU, reading it from the CPU core sensor. The CPU is heated up by means of OverClock Checking Tool version 1.1.0 under maximum workload in a 24-minute test during which the system remains idle in the first and last 4 minutes.
The mainboard’s automatic fan speed management (Q-Fan technology) is disabled for the time of the tests. The thermal throttling of the Intel Core 2 Duo processor is controlled with RightMark CPU Clock Utility version 2.25. Our CPU begins to skip clock cycles on reaching a temperature of 82°C and higher.
I perform at least two cycles of tests and wait for 20 minutes for the temperature to stabilize during each test cycle. The maximum temperature of the hottest CPU core in the two test cycles is considered as the final result (if the difference is not bigger than 1°C – otherwise the test is performed once again). Despite the stabilization period, the result of the second cycle is usually 0.5-1°C higher.
The noise level of each cooler was measured according to our traditional method. The subjectively comfortable level of 36dBA is marked with a dash line in the diagram; the ambient noise from the system case, without the CPU cooler, was about 34dBA.
The ambient temperature was monitored by means of an electric thermometer and remained at 20.5-21.0°C during the tests (marked with a vertical red line in the diagrams). The fan rotation speeds are shown in the diagrams as reported by SpeedFan. ASUS’ P5K mainboard series does not support PWM-based regulation of the CPU fan, so I set the subjectively quiet mode for the Xigmatek HDT-S1283 manually with SpeedFan.
The specs table suggests what I’m going to compare the new coolers with, but I want to tell you more about them. The Enzotech Ultra-X has heat pipes of the same diameter. This cooler was tested with its standard fan in two modes: a quiet 1140rpm and a maximum 2530rpm. I also added the Thermalright Ultra-120 eXtreme as one of the best coolers overall. I tested it with a Scythe Minebea 4710KL-04W-B29 fan at 1100rpm and 1900rpm. The Thermalright SI-128 was tested with the same fan and at the same speeds.
Here is the temperature of the overclocked quad-core CPU with each cooler:
As you can see, there is a negligible difference between the coolers when tested within a system case. We already know the capabilities of the Enzotech Ultra-X and Thermalright Ultra-120 eXtreme, and now we can see that both new coolers with 8mm pipes look excellent against them. The Thermalright SI-128 and Xigmatek HDT-S1283 easily cool the CPU, which is hot by itself and works at an increased voltage, even in the quiet mode. The first three coolers are also similar on the open testbed. The Thermalright Ultra-120 eXtreme is just a little better then than the others.
To get a fuller picture of performance of the coolers I also found the maximum CPU frequency achievable with each of them. To reduce the effect of the system case on the results I performed this test on the open testbed only. Here are the numbers:
The CPU voltage differed between the coolers in this test:
Although the coolers do not differ much in terms of the maximum CPU frequency achievable with them, we’ve got an obvious leader. It is the Thermalright Ultra-120 eXtreme that kept the CPU functioning at an unprecedented 3636MHz. The new mainboard, increased CPU voltage and efficient fan also contributed to that result. I had only managed to overclock the Core 2 Quad Q6600 to 3357MHz with the Ultra-120 eXtreme before.
The next diagram shows the amount of noise produced by each cooler:
The Ultra-120 eXtreme is quieter than the SI-128 despite the use of the same fan. This must be due to the position of the fan inside the system case. The difference is small, though. The 120mm fan of the Xigmatek HDT-S1283 is quieter at 1330rpm than the Scythe Minebea at 1130rpm. Its soft hanger on rubber pins and 7 blades produce less noise than the aggressive 9-blade Minebea. The Xigmatek is louder at the maximum speed, however. The Enzotech Ultra-X is the loudest cooler in this review.
Conclusion
The coolers from Thermalright and Xigmatek have both done well in my today’s tests. They are sure to gain recognition among overclockers due to their very high performance and low noise level, compatibility with every modern platform and competitive pricing. The Xigmatek HDT-S1283 is a leader in terms of performance/price ratio as it costs less than the other three coolers (and you have to buy fans separately for Thermalright’s heatsinks). As for drawbacks, the mainboard bends rather unpleasantly under the Thermalright SI-128. You have to press on the locks quite heavily to install it, which is not easy to do inside a system case.
I would also like to return to the thought I expressed in the Introduction to the Cooler Master Sphere review. You can take a look at the maximum CPU frequency you can achieve with the coolers in the quiet mode and you’ll see that the difference is small. The coolers do not differ much in the performance test as well. This is another confirmation of my point that the potential of air cooling has virtually been exhausted by now. Perhaps there’ll be new super-coolers soon, but you shouldn’t expect them to be much better than the existing ones. Considering today’s abundance of high-performance air coolers, the overclocker should make his choice basing on such factors as price, noise level, availability, compatibility, and the opportunity to orient the cooler in the best possible way on the mainboard. And the two models I discussed in this review make your option of choice even broader than before.
