We'll discuss the full speed results first. On the LGA1150 system, the Atlas matches the Gelid Antarctica with a delta T of 47°C. Gelid's cooler uses a single, thin tower, is £10 less expensive and also quieter thanks to using just one 140mm fan, so you do lose out when moving to a height-limited cooler. That said, it's a good 5°C better than that Thermalright Macho 90, which is actually 10mm taller too (though also quieter), and is a pretty good result still for a powerful, overclocked CPU like this.
The LGA2011 system was always going to be a big challenge, but the delta T of 54°C is not terrible. We don't have similar size coolers to compare to here, but it's a good 7°C better than SilverStone's Argon AR01.
Click to enlarge - There's enough clearance for low-profile RAM module, which you'll need if using an LGA2011 system (right)
Lastly, we have the AMD system, and while the Atlas cannot match the temperatures of any air coolers that use larger fans, it is again considerably better than the Thermalright Macho 90, though the noise from its two full speed fans is also higher.
With both fans connected to the supplied 7V adaptors, the noise of the fans is immediately reduced. They aren't loud to begin with as such, but they're certainly easy to hear, which is no longer the case when limited to 7V. Sadly, the temperatures skyrocket, increasing by between 13°C and 20°C depending on the socket, and even failing on the LGA2011 rig where our CPU was forced to downclock. Such a wide disparity between the two results suggests that the fans aren't well tuned the design of the cooler fins, and that their airflow at 7V isn't enough to cope with the density.
Click to enlarge - On LGA1150, having the fan at the front means you need low-profile memory, while at the back you'd need to remove the exhaust fan
It's wrong to expect chart-topping performance from a cooler that's only 125mm tall, but even so we are still a little underwhelmed by the Atlas, particularly with regards to the low-speed results. After all, it's still pretty beastly with fans attached. Other little niggles like the occasionally fiddly installation process and non-braided adaptor cables are also harder to overlook in a £45 cooler. The Macho 90 is admittedly 10mm taller, but even though its maximum cooling performance isn't as good as the Atlas's, we think it strikes the better balance once noise is factored in, and it's also a bit less expensive. Still, this is a niche product by design, and if you truly need to make the most of a height-limited chassis, the Atlas could well be for you, as it is still capable of taming overclocked, high-end processors.
Intel LGA1150 Scores
Intel LGA2011 Scores
AMD Socket AM3+ Scores