In the arena of overclocking there seems to have been a trend over the past few years in the area of high end air coolers. The best of the best seemed to have several things in common, dense fin or pin arrays, and huge blocks of copper. One such trendsetter, Thermalright, has recently been turning heads with a new line of air coolers, the aluminum finned and heat pipe clad XP series. Today we are going to look at the AMD64 version of the XP-90 and see how it compares to a stock heatsink under overclocked and normal thermal loads.
The heatsink comes packaged in a solid brown cardboard box, clad with Thermalright markings. Upon opening the box you can see that the packaging engineers knew what they were doing. The sink is suspended in cardboard, wrapped in plastic and it seems empty space was filled with foam.
After removing the heatsink package you can see that Thermalright incorporated every part into the package. Everything has its place. Maybe it’s just me, but I enjoy knowing that a company takes the extra steps to ensure that their product arrives to the customer in quality packaging. Thermal right also included a large list of accessories to make sure that you have everything you need for the installation.
Accessories included with the Heatsink include:
- Mounting bracket
- Screws
- 92mm fan clips
- 80mm fan clips
- Rubber fan mounts
- Large tube of thermal compound
- Step by step mounting instructions
- Even a Thermalright sticker
What I was surprised to find however, after all of my boasts regarding Thermalright packing, was that some of the fins were bent on the side of the heatsink after removing it from the cardboard. Be careful, otherwise you will find yourself with a set of needle nose pliers, straitening fins for 10-20 minutes.
Design
One thing you will notice the moment you unveil this heatsink its size. It is about 4 ½ inches long and 3 inches high. The design itself is comprised of an interlocking, dense array of aluminum fins. The fins extend down to the processor across roughly half its length.
In addition to the fins there are four heat pipes. Heat pipes are closed metallic tubes that generally contain a phase change liquid in side. Heat is applied to one end of the pipe, which in turn changes the liquid to vapor where it moves to the other end of the pipe where heat can be removed. In this design the heat pipes are enclosed into a nickel plated copper base where heat from the processor will be applied and then whisked away and distributed to the top of the fin array.
Here a fan will remove the heat from the fins through forced convection. It seems the theory behind this design is to remove heat as quickly as possible (higher heat transfer rate – aluminum fins dissipate heat faster than copper using forced convection) as opposed to having a high heat capacity (large copper bases and fins – copper has a higher heat capacity and conduction rate than aluminum). This tends to explain such a drastic change from what many would consider a usual design from Thermalright.
The heat pipes themselves are soldered to a flattened section of the fins of the heatsink. This provides drastic improvements in heat conduction from friction fitting or metal on metal contact. Heat pipes attached without solder would be similar to attaching a heatsink to a processor without thermal compound. Several things I noticed however was that the fins above the heatsink base have divets in three places (probably to increase air turbulence, increasing efficiency of forced convection) and that heat pipes in the base do not extend through the entire length.
The base of the heatsink has been milled flat from a copper cast profile that has been nickel plated so that the aluminum fins can be soldered directly to it for better heat transfer. The base shows circular machining marks that you can feel when you run you’re your fingernail across it. Hand lapping the base could possibly improve this heatsinks performance.
This heatsink does require you to buy your own fan. This can be good if you like to customize your sink with different fans, but bad if you don’t want to spend any more money. I chose a quality Panaflo unit rated at 57cfm and 35dB. To mount a fan on this heatsink, you use unique wire spring clips that slide into holes in the sides of the fins. These clips slip over the holes in the housing of the fan that you would normally put screws through.
Thermalright also threw in thin rubber strips which you place under the fan housing. These should help reduce some noise from vibrations traveling through the fan to the heatsink. When completely mounted, the fan is very snug and secure. I can’t see any situation short of violent shaking that would bring this fan from its mounting. Overall, the unit looks solid, well constructed and well engineering. Aesthetically if you like an industrial look to your parts, you should be happy with this heatsink sitting in your case.
Mounting
To mount the XP-90 you need to use a proprietary mounting bracket provided as an accessory. The bracket is made of a dense, hardened plastic that is a direct swap for the original that comes with K8 motherboards. Just use the supplied screws. The heatsink mounts with a spring loaded hook system at all four corners of the bracket.
Just angle the heatsink 45 degrees, attach two of the hooks and then rock the heatsink back to hook in the other two. It is easiest to do this outside of the case but can be done inside if the bracket isn’t too obstructed. One thing to note is that with certain motherboards (such as this Abit AV8) you will find that some of the hooks, and when angling the heatsink you can hit components on the motherboard. This can make your life a bit harder when mounting this heatsink.
When fully mounted the unit was very solid and there seemed to be a good amount of mounting pressure. I don’t feel there would be any risk in this heatsink falling off while transporting a case, if installed properly. Also, I just wanted to mention that while checking the thermal compound imprint, it dawned on me why Thermalright made the heat pipes go through only part of the heatsink base. The processor only contacts the first 1 ¾” of a roughly 2” base. So the heat pipes only extend through the processor contact area of the base.
Test System
Testing of the Thermalright XP-90 was conducted on the following system (Note: motherboard is not the one pictured during installation):
- MSI K8N Neo2 Platinum s939
- AMD64 3200+ 90nm Winchester
- PQI Turbo Dual Channel PC3200 @ 2-2-2-10
- ATI Radeon 9800 Pro 256meg
- Western Digital 36.7GB WD360DG Raptor Drive
- Western Digital 160GB 1600BB 2MB Cache
- Lite-On DVD-RW
- PC Power and Cooling 510 Deluxe
- Lian-Li PC6085 Case
The XP-90 will be compared against a stock AMD64 cooler which is milled from a solid block of aluminum and has a 70mm fan in push configuration. The fan on the XP-90 will be in pull configuration.
To compare how each handles increased heat loads of overclocked processors the heatsinks will be tested at two different processor speeds:
- Stock – 2.00Ghz, 200 HTT, 10x Multi, 200FSB, CPU@1.45v
- Overclocked – 2.38Ghz, 238HTT, 10x Multi, 194FSB, CPU@1.53v
Temperatures will be monitored through Motherboard Monitor 5.3.7.0 using the on chip die (for CPU) and system sensors (for Case). Take these measurements skeptically. The onboard sensors can be read differently from one system to another and can very large error percentages from actual true temperatures. Although both heatsinks are being tested on the same system under the same conditions, therefore the results are standardized for comparison.
In addition to CPU temperatures, I was curious to see how heat removal at the CPU could affect the temperature of other board components, such as the power MOSFET regulators (the six square chips lined up vertically in the following picture). I used an Infrared Temperature gun to measure the surface temperature of the topmost MOSFET.
The following shows cooling comparisons between the stock AMD64 cooler and the XP-90 under stock and overclocked conditions. As well as power MOSFET temperature at each state and the temperature difference between input case air temperature and chip temperature. Room temperature for all testing stayed within a range of 23C +/- 0.3C.
Conclusion
In regards to the impact the heatsink had on power MOSFET temperatures I was actually shocked. Initially I thought that it was because the higher output fan from the XP-90 caused more air circulation in the area, which may be part of the reason, but it is also commonly know that heat from processors dissipate vertically to the heatsink and down to the PCB. Therefore if more heat is being effectively removed from the processor, less heat output is being dissipated downward to the PCB , and the radially to other components on the motherboard. I can’t say for sure, but something to think about.
Performance of the XP-90 however was well above stock. This new design should give many a reason to break the copper clad trend. I can say that Thermalright has produced a product that even though it doesn’t follow the big copper heatsink trend, still performs. It is a solid, well engineering heatsink with clever features and good construction; couple that with a company that provides quality in everything down to the packaging their heatsinks go into, and you have a winner. For those looking for a K8 heatsink that provides top notch cooling not only at stock processor speeds but also overclocked, look no further than the Thermalright XP-90. I am giving this heatsink a 9.5 out of 10 and the OCmodshop Seal of Approval.
Pros
- Lighter than big all copper heatsinks
- Good fan clips
- Lots of accessories
- Detailed instructions
- 80 and 90mm fan mounting
- Solid mounting system
Cons
- Fins bend easily
- May hit motherboard components while mounting