Thermalright SI-97

Heatsink test – Joe

SUMMARY: An excellent choice for AMD CPU cooling, but noise may be an issue.


Size: 116 x 96 x 75 mm; Weight: 280 grams.

The good guys at Thermalright were nice enough to send their latest, the SI-97 for a test spin.

Looking at this from the side


reminds me of the Enterprise – it’s quite an elegant design.

The SI-97 ships with parts for Socket A mounting, including a copper shim:


Fans ranging from 80 to 92 mm can be mounted on the SI-97. The socket clip engages all three lugs – a very secure system.

The base is well finished:


When I ran my nail over it, I could not feel or hear any ridges.


I tested the SI-97 with Vantec’s Tornado 90 x 38 mm fan; it features vanes in the base to straighten airflow off the blades. I varied voltages to get a range of fan speeds and measured rpms using an Omega digital tachometer.

I measured fan noise with a Radio Shack sound meter 8″ from the fan’s intake. These are not comparable to noise levels reported by fan manufacturers; noise is usually measured at three feet from the fan.

The SI-97 was tested on the CPU Die Simulator which gives results that are unaffected by motherboard influences.


Die Temp
Ambient Temp
SI-97, Vantec 90, 4917 rpm, 77 dBA
39.3 C
22.3 C
17.0 C
SI-97, Vantec 90, 40185 rpm, 70 dBA
40.3 C
22.8 C
17.5 C
SI-97, Vantec 90, 3016 rpm, 63 dBA
41.6 C
22.7 C
18.9 C
SI-97, Vantec 90, 2006 rpm, 51 dBA
43.2 C
22.3 C
20.9 C

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.

Die Simulator results place the SI-97 in the topmost rank of heatsinks tested to date (Heatsink Ranking).


Thermalright’s SI-97 is an excellent choice for AMD CPU cooling. However, the more aggressive the fan used, the higher the noise level – no surprise. If you want top performance while gaming but quiet at other times, I would recommend using an aggressive 92 mm fan with a rheostat – especially if your PC is “24-7”.

Thanks again to Thermalright for sending this our way.

The SI-97 is available now from The Heatsink Factory.

Email Joe