Performance

Straight after mounting, the heatsink was demounted and contact was checked. There was a very strong suction force, and even after twisting, the block would not come off easily. The thermal paste was spread out evenly over the CPU and the bottom of the block.

I decided to test temperatures on my Opteron 144. For initial testing, I used the integrated diode – actual values were then measured using a copper midplate and a Fluke 54 II Thermometer and thermocouple.
Idle temperatures were measured after 30 minutes of the PC idling at desktop. Load temperatures were measured after 30 minutes of CPUBurn K7.

The TDP of an AMD Opteron 144 (1800 MHz, 1.39V) is 67 W. At 2502 MHz, 1.55V, the TDP is 115 W, at 2700 MHz, 1.55V, the TDP is 125 W.

The Alphacool kit used during testing was made up of the following:

• Pump: Eheim HPPS+ in Power mode
• Alphacool Nexxos XP Bold
• Black ICE Xtreme II with 2 Sunon 7W fans
• AGB-O-Matic plug-on reservoir

So, I launched CoreTemp, and to my surprise, the idle temp was quite high – around 45°C. Then, I started CPUBurnK7, and temperatures quickly rose to 55°C. I thought that I must have had a bad mount, so I remounted the heatsink, and tried again – with the same result.
I repeated the procedure several times, each time getting high temps. Then, mounting pressure came to mind: instead of cranking down the screws fully, I only tightened them one turn. Idle temperatures instantly improved to 30°C idle, yet load still shot up to 50°C. I then tightened down the cooler a bit more, achieving even lower temps – until I ended up with the best temperatures.
A note of warning: as soon as the cooler is screwed down fully, temps do not improve if the screws are loosened again – this could be perhaps due to all the TIM being squeezed out, or maybe some other reason.