Thermalright XP-90

Heatsink test – Joe

SUMMARY: An excellent choice for P4/K8 cooling.


Size: 110 x 125 x 63 mm (ex fan); Weight: 360 grams.

The good guys at Thermalright were nice enough to send their XP-90 P4/K8 heatpipe heatsink for a test spin. In contrast to some heatpipes I have tested, the heatpipes are soldered to the copper base – some used thermal paste instead, with performance suffering as a result.


Mounting is straight forward – ther are two clips which engage the P4 retention bracket. The preferred mounting procedure is to engage the two clips at the back end of the heatsink and then rock it forward toward the RAM slots to engage the retention bracket. There are parts for a K8 barcket as well.

The base is well finished:


When I ran my nail over it, I could not feel or hear any ridges. Note also the relative elegance of the design – a base, heatpipe and fins; this is not a heavyweight by any means.

Parts that ship with the unit allow for P4 and K8 mounting.


The Test

The Thermalright 90 mm P4 Heatpipe was tested on an Acorp 4S845A motherboard with a modified P4 1500 to read CPU case temps. For testing, I used 90 mm Vantec Tornado – I varied rpms to give a noise and performance range. Thermalright recommends using a Panaflo #FBL09A12M fan – this is a 92mm unit that specs at 2450 rpm, 48 cfm, 30 dBA.

TEST RESULTS – Acorp 4S845A Motherboard

CPU Case Temp

Ambient Temp



MBM Temp

Vantec 4821 rpm, 76 dBA²

34.1 C

26.7 C



31 C¹

Vantec 4035 rpm, 72 dBA²

34.4 C

26.6 C



31 C¹

Vantec 3004 rpm, 64 dBA²

35.3 C

26.6 C



32 C¹

Vantec 2456 rpm, 58 dBA²

36.4 C

27.2 C



34 C¹

Vantec 1500 rpm, <50 dBA²

39.0 C

28.4 C



37 C¹

¹MBM on-die temperatures.

²50 dBA measured 8″ from the fan intake corresponds to about 30 dBA measured 3 feet from the fan; this is a very quiet noise level. The 90 mm fan at 1500 rpm is very quiet.

Die Simulator results place Thermalright’s XP-90 heatpipe in the topmost rank of P4 heatsinks tested to date (Heatsink Ranking).


Thermalright’s XP-90 heatpipe is well made and an excellent choice for P4/K8 cooling. Mating Thermalright’s Heatpipe with a rheostat controlled fan might be the preferred approach for the power user looking for peak performance followed by a quiet night’s sleep.

Thanks again to Thermalright for sending this our way.

The Thermalright XP-90 is available from The Heatsink Factory.

Email Joe