SUMMARY: OK choice for AMD Athlon 64 and Opteron cooling under “normal” conditions.
Size: 78 x 68 x 37 mm
The good guys at AVC were nice enough to send their latest heatsink for AMD Athlon 64 and Opteron for a test spin, the AVC #Z7UB301001
Key features include:
Ball bearing, thermal sensor 70 x 20 mm fan
Fan rated at 2900 rpm @ 32ºC, 5400 rpm @ 42ºC
Air Flow 25 – 52 cfm
The AVC ships with an AVC 70 x 20 mm thermally controlled fan (DS07020B12U) which varies from 2900 rpm @ 32ºC to 5400 rpm @ 42ºC. I found it to be tolerably quiet at 3000 rpm – I measured noise at less than 50 dBA¹ with a Radio Shack sound meter 8″ from the fan’s intake, very quiet; noise will increase, however, as ambient temps increase.
The base is not very well finished:
When I ran my nail over it, I could feel ridges – they are also quite visible.
The mount features a backing plate:
The “3M Performance” is protective paper for the sticky tape on the base plate; once installed, the backing plate should not move. The heatsink is held on by a lever
which swings down to engage a clip on the mounting base – very secure and simple to mount. This heatsink ships with a TIM which was removed for this test.
The AVC was tested on the CPU Die Simulator which gives results that are unaffected by motherboard influences. For testing, I varied voltages to give a range of rpms so users might have a better understanding of noise levels under different load conditions.
TEST RESULTS – CPU Simulator
AVC, 3061 rpm, 69.6 watts
AVC, 3031 rpm, 30.2 watts
AVC, 3027 rpm, 11.8 watts
Delta = CPU temp – Ambient Temp
C/W = Delta / CPU Watts
Interpreting C/W: For every watt (CPUw) that the CPU
consumes, the HSF will limit the CPU’s temperature rise to (C/W x CPUw)
plus the temperature at the HSF’s fan inlet. For example, at an ambient temp of 25 C, a C/W of 0.25 with a CPU radiating 50 watts means that CPU temp will increase 50 x 0.25 = 12.5 C over ambient temp, or 37.5 C. The lower the C/W, the better.
Sharp-eyed readers will notice that fan rpms, under different power loadings, did not vary; the design of most thermally controlled fans places the thermistor in the fan’s hub, as does the fan for this heatsink:
As such, the thermistor reacts to ambient air temps, NOT heatsink temps². Since ambient air temps in this test did not vary appreciably, neither did fan speed.
However, in a closed case, ambient temps may increase as power increases due to heat dumping into the case. In this situation, you will most likely hear an increase in rpms as you stress the CPU. Also note that C/Ws do not substantially change with power load – heatsinks deliver the same C/Ws regardless of power load (under spec loading).
Die Simulator results place the AVC in the mid rank of heatsinks tested to date (Heatsink Ranking).
AVC’s #Z7UB301001 is an OK choice for AMD 64 bit cooling, although I would not use it for aggressive cooling. For “normal” use where CPUs will not be overly stressed, AVC’s #Z7UB301001 looks like a good choice.
¹Note that manufacturers measure fan noise usually 3 feet from the fan; I measure noise 8″ from the fan’s intake.
²There may be limited thermal feedback from the heatsink, but this does not correlate well with CPU temps.