Test Results

The Silent Square lines up nicely with the rear 120mm fan on this DFI motherboard:



If you have a side panel with window you'll appreciate the LED fan Asus used, it gives the S² a touch of class. If however you don't have a window in your side panel (like me) this extra detail is lost.



The Silent Square seems like a capable heatsink, for the performance comparison I've included Asus' previous entry the X-Mars (with its fan set to auto speed) and the stock AMD Heat pipe cooler. The included BLUE led fan was used at 100/50% speed, I also installed my reference Delta 92mm fan. At full speed the Asus 92mm fan runs at ~1900rpm, at 50% voltage the rpm drops back to ~710rpm. (in comparison the open framed Delta runs at ~1500rpm @ 100% and ~690rpm @ 50%). Let's see how it did:



Very impressive results with the 92mm fans at 100%, the noise difference between the Asus and Delta is only ~1dBA; CPU temps are identical, yet PWM is slightly higher with the Delta fan. At low fan speed the noise drops to a very silent 35dBA and performance is still excellent. Let's see what happens when we increase CPU speed & voltage:



Any heatsink able to keep this hot K8 CPU running below 70°C at low noise is a worthy HSF solution, the Silent Square however falls into the "excellent" category, matching the CPU temp results of other high end heatsinks like the Tuniq Tower 120 and Scythe Ninja (compare here). PWM temps are quite high but nowhere near critical values.

If Asus decides to release an upgraded version of the S² with 120mm support (and maybe throw in another heat pipe) they make take the performance/noise crown.

Conclusion

The Asus Silent Square is a very competent cooling solution, keeping temperatures down, whether the CPU is overclocked or not. The included fan at full speed is relative silent, yet turned down to 50% it becomes inaudible. The installation requires motherboard removal but that's the only drawback, the compact size of the HSF allows for wide motherboard/case compatibility.

Platform support is a bit unclear, the product page at Asus states S775/S478 for Intel and K8 S939/S754 for AMD, but it's motherboard compatibility list includes AM2 motherboards and a special 90° rotation bracket. Without the bracket the S² lacks AM2 support and the ability to freely rotate it in 90° steps on the K8 platform, this in turn can lead to a less than ideal orientation.

Edit: Update 20/10: Asus informed me that the Silent Square PRO supports AM2, not the version reviewed here. The special 90° rotation bracket is also only for the PRO version.

PRO
Excellent performance
Silent LED fan (inaudible at reduced speed)
Fair price ~€35/$45

CON
not AM2 compatible
Orientation depends on socket, will not always be installed optimal on all motherboards (K8 S939)

I like to thank Asus for sending over the product for testing;

Questions/Comments: forum thread