Testing:

In order to keep test results equal across the board, all cooling testing is done with the following setup, conditions and methods:

Test System:

AMD Phenom II 1100T at stock 3.3GHz (125-watt TDP)
Asus M5A99FX Pro mainboard
4GB Corsair Dominator DDR3 RAM
Windows 7 Ultimate 64-bit
Radeon HD4870 video
Thermaltake Toughpower Grand 850-watt PSU
Thermaltake Spedo Advance full-tower case
120mm intake case fan (x2)
120mm exhaust case fan

Ambient temp in the testing environment is brought as close to previous testing levels as possible and recorded at the beginning of the test.  For this test ambient was 24.9C and remained stable within .3 degrees for the duration of the testing.

Before testing begins, BIOS power/performance settings are set to "balanced" mode and the system is allowed to idle for 30 minutes to get a stable idle temp.
 
Stress testing is done with OCCT 4.4.0, running 30 minutes on each set, with large data set and a 1-minute idle time recorded at the beginning and end of each test.  If a cooler has multiple modes (high and low fan speeds, for instance), the test is run for each mode and all results recorded.
 
Tests are performed using Noctua NT-H1 thermal interface material for equal comparison with other cooling solutions.

For acoustic testing all case fans are connected to a Sunbeam rheobus fan controller and their speed is lowered to the point that they are inaudible.

So how did the flagship cooler from Raijintek perform?

The best performance from Raijintek so far, as is to be expected.  Even with the slightly higher ambient temp it outperformed the Ereboss and Themis Evo coolers by 3 degrees.  While this is very good performance, keeping this 125-watt CPU even below AMD’s recommended thermal threshold of 62 degrees during this torture test, I am again left scratching my head.  I had expected the Ereboss to outperform the Themis Evo due to its increased surface area, but the test results were nearly identical.  Likewise, I had expected the Nemesis so beat both of these smaller coolers soundly, only to see a 3-degree difference.  With the Ereboss I was able to explain some of the test results with the difference in the base, as the Themis Evo enjoys the benefits of direct-touch heatpipes while the Ereboss does not.  This variable has been eliminated here however, as the Ereboss and Nemesis coolers seem to share an identical base.  As odd as it sounds, perhaps this 6-core CPU isn’t hot enough.  Might we see a more marked difference between them with a hotter overclocked CPU?  That may be a test to run in the future, simply to satisfy my own curiosity.  As it stands, the Nemesis definitely does outperform all of the other Raijintek coolers.

Noise levels:

As with the Ereboss before it, it wasn’t the cooling performance that really set this cooler apart so much as the noise level.  Where the Ereboss performed equally as well as the Themis Evo, it did so much more quietly.  In this case, the Nemesis actually managed to best the Ereboss in both areas.  The Nemesis is among the quietest coolers I’ve had the pleasure of using.  Even at the peak of the test it was quiet.  I’m certain that with a manual fan controller the fans could be slowed to totally inaudible level and the cooler would still perform very well in everyday tasks.