Spire SP495S11-U P4 Heatsink

SUMMARY: An OK choice for low-noise, non-aggressive P4 cooling.


Size: 100 x 83 x 50 mm.

The good guys at Spire were nice enough to send a sample of the SP495S11-U QuieTude VI ™ P4 Heatsink for a test spin. The fan is rated at 2300 rpm, 25.8 cfm @ 19 dBA – low noise, but at the expense of airflow. The heatsink is rated for Intel Celeron D ~ 2.93 GHz, Pentium 4 ~ 3.6 GHz (Prescott) and Pentium 4 ~ 3.4 GHz (Willamette).

Mounting is straight forward – there are two clips which engage the P4 retention bracket – very simple and secure.

Construction is aluminum with a round copper base insert. The base could be finished better:


When I ran my nail over it, I could feel ridges; this heatsink ships with thermal grease pre-applied, although in testing I removed it.


The Spire SP495S11-U was tested on an Acorp 4S845A motherboard with a modified P4 1500 to read CPU case temps.

TEST RESULTS – Acorp 4S845A Motherboard

CPU Case Temp

Ambient Temp



MBM Temp

2380 rpm, <50 dBA²

43.1º C

23.3º C



35º C¹

¹MBM on-die temperatures.

Die Simulator results place Spire’s SP495S11-U in the lower rank of P4 heatsinks tested to date (Heatsink Ranking).


Spire SP495S11-U is an OK choice for non-aggressive CPU cooling. Fan noise is low and performance, as expected, is the tradeoff.

²Note that manufacturers measure fan noise usually 3 feet from the fan.

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