Thermalright XP-120 Heatsink

Several months ago, Thermalright’s SP-94 was toppled from its position as the best Pentium 4-compatible air cooling solution on the market by the latest crop of “tower” style heatsinks, such as the Coolermaster Hyper 6 and the Aerocool HT-101. These heatsinks managed to outperform the SP-94 by virtue of their far greater surface area and the use of up to six heatpipes to distribute heat across that surface area as rapidly as possible. However, Thermalright has come back with a vengeance. Their latest heatsink, the XP-120, is truly unique. But, how does it perform?

Materials: Copper and aluminum, possibly nickel
Construction: (nickel?) plated copper base, soldered aluminum fins
Dimensions: approximately 125x130x63mm
Weight: 370g without fan
Compatibility: Socket 478

Due to the fact that much of the XP-120 is aluminum, it actually weighs less than the Intel retail heatsink and fan. Even after adding a 120x25mm fan, the XP-120 weighs only around 100g more than the Intel solution. Although it uses the stock Pentium 4 heatsink retention mechanism, it is actually quite securely mounted.

The XP-120’s large size does pose one major problem: it isn’t compatible with all Pentium 4 motherboards. I found this out the hard way, when I discovered that the XP-120 would not fit on my DFI LANParty Pro875B motherboard. I then tried it on my ABIT IC7-G Max II Advance, only to find that it did not fit on there, either. I took the heatsink to a local computer store and test fitted it on all of the Pentium 4 motherboards they had on display. Here is a (far from complete) compatibility list:

Although the heatsink is well built, as is typical of Thermalright, its base left much to be desired. While it was significantly smoother than the bases of previous Thermalright products, machining marks were still visible. These were also easily felt by dragging a fingernail across the heatsink’s base.

The base was also somewhat concave, however this apparently didn’t impact performance to a great degree (load temperatures dropped only 1-2 degrees Celsius after lapping it on a granite surface plate calibrated to +/- 0.0001″) but I expect a better quality base than this on a $50 heatsink.

Test Setup

The heatsinks were tested on a system with the following specifications:

• Motherboard ASUS P4P800-E Deluxe
• CPU 2.8GHz Pentium 4 “E”, Prescott core, HT enabled
• Chipset Intel 865PE
• RAM 2 512MB sticks of generic DDR400, 1GB total
• Video ATI Radeon 8500 64MB DDR with a 1u CPU HSF on it
• Hard Drives 80GB Western Digital SE 800JB 7200RPM/8MB/ATA-100
• 80GB Maxtor DiamondMax 9 7200RPM/8MB/ATA-133
• Power Supply 550w Enermax EG-651P-VE

• Operating System Windows XP Professional
• Test Software Motherboard Monitor 5
• Folding @ Home

Heatsinks

• Intel 2.8EGHz Retail HSF
• Thermaltake Spark 5+
• Thermalright XP-120

Fans

• Intel stock fan
• Thermaltake stock fan
• 120mm Vantec Stealth (53cfm)
• 120mm Thermaltake SmartFan Blue model A2018 (93.7cfm)
• 120mm Y.S. Tech (approximately 130cfm)
• Thermal Compound Arctic Silver 5

The system was assembled outside of a case on top of my desk. It was booted and allowed to idle for approximately 15 minutes. Two instances of Folding @ Home were then started and allowed to run for approximately 15 minutes more. Folding @ Home was then closed, the system idled for another 5 minutes to cool down, and then the heatsink and/or fan was changed. Between each heatsink swap, a fresh layer of Arctic Silver 5 was applied. The room temperature was maintained at 70 degrees Fareneheit (21 degrees Celsius) throughout the testing.

Test Results

It’s clear that the XP-120 is really in a class by itself in terms of performance. 41 degrees Celsius under full load with a near-90w heat load is truly incredible for air cooling. What is interesting is that the performance did not improve by going from 94cfm to 130cfm. The limiting factor seems to be getting the heat into the heatsink; the XP-120 didn’t get any warmer than room temperature to the touch with either of the two higher flow fans, and even with the Stealth fan, only the heatpipes got very mildly warm.

One beneficial side effect of the XP-120’s design is that on many motherboards it will cool the power circuitry for the CPU as well as the CPU itself. In the case of the P4P800 that I tested it on, the XP-120 dropped the power circuitry temperature by an average of 10 degrees Celsius under full load.

Conclusions

Thermalright’s XP-120 is an outstanding heatsink—easily the best performing heatsink that I have ever used—but that performance comes at a price: it may not fit your motherboard of choice. Beyond that, although it did not impact performance in any significant way, I don’t appreciate a $50 heatsink having a poorer quality base than many of the $20 heatsinks I’ve used.

The bottom line is that the XP-120 is an outstanding heatsink for both silent computing enthusiasts and overclockers. Even with the nearly silent Vantec Stealth on it, the XP-120 is easily powerful enough for very serious overclocking, and in fact, going to much higher airflow (and much noisier) fans netted almost no performance increase.

Assuming that it fits on your motherboard, the Thermalright XP-120 is the best heatsink on the market. Highly recommended.