Scaling of Cooling Performance

The Thermalright Ultra 120 Extreme has been the top performer so far in CPU cooling at stock speeds. As overclocks were raised, the performance the Ultra 120 with the Scythe SFLEX fan maintained its cooling advantage. The OCZ Vindicator is average or below average in cooling efficiency with the stock fan. It is clear the stock fan was selected for low noise and not cooling efficiency. However, a swap to the 14 dB-A 72 CFM SilenX fan improved cooling to the levels of the Cooler Master Hyper 6+ and Scythe Infinity - two coolers that reached upper tier cooling performance in our reviews.


At 2.93GHz the retail HSF is running at 41C, compared to 32C with the OCZ Vindicator with the stock fan. This is a delta of 9C. The SilenX drops that temperature to 29C, or a delta of 12C. The delta increases slightly with the stock fan as the overclock increases. At 3.73GHz the idle with the retail fan is 56C compared to the Ultra 120 at 46C - a delta of 10C! Performance improvements are much greater with SilenX fan on the OCZ Vindicator. At 3.73GHZ the SilenX cools to 42C, while at the highest stable overclock of 3.90GHz the Vindicator/SilenX is at 44C. This almost straight line at idle at the top of our testing is an indication the SilenX is effectively cooling at idle all the way to the top speed that could be reached in benchmarking.

Cooling efficiency of the Vindicator, with stock and SilenX fans, was next tested under load conditions. Results are compared to the retail HSF and other recently tested CPU coolers. The OCZ Vindicator with the SilenX fan generated results similar to the Scythe Infinity with Push-Pull fans and reached the upper tier of overclocking performance. Results with the single stock fan were average at best.


By 3.90 GHz - the highest overclock the Tuniq, Thermalright Ultra 120, and Cooler Master Hyper 6+, and push-pull Scythe Infinity could reach with stability - the Vindicator is at 65C with the SilenX fan. This is still worse performance than many of other top coolers at this speed. The Tuniq and Ultra 120 are both at 51C, which is some 14C lower than the Vindicator. Keep in mind that the Vindicator was completely stable at 3.90GHz with the SilenX fan even though it ran a bit warmer. The stock fan could only manage 3.80GHz so the SilenX is a much better fan for overclocking the OCZ Vindicator.

As stated many times, the overclocking abilities of the CPU will vary at the top, depending on the CPU. This particular CPU does higher FSB speeds than any X6800 we have tested, but the 3.9GHz top speed with the top tier heatpipe towers is pretty average among the X6800 processors we have tested with Tuniq cooling. A few of the other processors tested with the best air coolers reach just over 4 GHz, but the range has been 3.8 to 4.0GHz. Stock cooling generally tops out 200 to 400 MHz lower, depending on the CPU, on the processors tested in our lab.

Cooling at Stock Speed Overclocking and Noise
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  • Spoelie - Thursday, April 5, 2007 - link

    I would also like to know a more quantifiable difference between the stock fan and this silenx fan. The noise measurements are kinda useless since they put everything on the same level. But do they actually sound all the same? Is the silenx really quiter?? Would be kinda strange.

    So even if it is like (this one sounds louder as that one, and when i put my hand before them i can feel more air move with this one than with this one) than we can at least confirm what each fan does, just not by how much. The only thing we know at this moment is that the silenx moves more air, judging by the temperatures.

    silentpcreview is really good, but the focus on these articles is different, they're more geared to overclocking. So while some critique is valid, this article is not trying to be a definite one on the noise front or a competitor to what silentpcreview does.

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