Cooler Comparison Testing
Cooler Testing Methods
To best gage the quality of the system coolers under review, system CPU temperature and cooling system audio measurements were taken with the CPU idle and under load. To replicate CPU idle conditions, the system was rebooted and allowed to sit idle for 10 minutes. To replicate a stress system load, AIDA64 System Stability Test was used in conjunction with EVGA OC Scanner X for 30 minutes per run. After each run, the system was shut down and allowed to rest for 10 minutes to cool down. Then the CPU cooler was removed, cleaned, and remounted to the CPU with fresh thermal paste applied. This procedure was repeated a total of 12 times for each cooler – three times each for the stock and overclocking speed runs on the Z97 and X99-based systems.
Temperature measurements were taken directly from the CPU thermistors using CoreTemp v1.0 RC7. Because of the volatile nature of the Haswell and Haswell-E thermistor readings, the system temperatures were measured as follows. For idle temperatures, the highest recorded value was used for the run. For load temperatures, a series of three values were notated: the average (high and low) across all cores, the average (high and low) across the single highest core, and the high temperature.
To adequately measure the performances of both coolers, performance testing was done for all scenarios under single fan mode using vendor provided fans. Fans were directly connected to the PSU and run at full speed for all tests performed. The Okeanos cooler was tested using three different configurations – in its dual fan stock configuration, its dual fan configuration using the Low Noise Adapters (LNA) included with the unit, and in a triple fan configuration. The Brontes cooler was tested in its stock single fan configuration only.
Note that the temperature values are reported as deltas rather than absolute temperatures with the delta value reported calculated as CPU temperature – ambient temperature. For all tests, room ambient temperature was maintained between 23-27C. Sound measurements of the system cooler where taken with the sound meter placed 3 feet away from the system with all other devices in the room silenced. The Sound Meter Pro applet on a Samsung Galaxy S5 mobile phone was used to measure decibel level.
Intel Z97-based Haswell System Testing
CPU Stock Speed Testing
The CPU stock speed testing was conducted with the BIOS defaults set for the CPU (including enabling of the CPU-integrated graphics processor) and Turbo Mode disabled, equating to a 3.4GHz CPU speed, 1600MHz memory speed, 3.4GHz ring bus speed, and 100MHz base clock. The Intel Speedstep functionality remained enabled for the duration of the testing to get realistic CPU idle performance conditions.
Compared with the other test coolers, the Reeven cooler's performance fell higher than expected. There seemed to be little performance difference when using the Reeven Okeanos in its stock configuration, with the Low Noise Adapters (LNA), or with three fans cooling the beast. The Reeven Brontes cooler was able to maintain system stability, but its cooling performance potential lagged all other coolers tested.
CPU Overclocked Speed Testing
The CPU overclocked speed testing was conducted with known stable settings from a previous board review with Turbo Mode disabled, equating to a 4.68GHz CPU speed, 2340MHz memory speed, 4.0GHz ring bus speed, and 167MHz base clock. Also, the CPU-integrated graphics processor was disabled to reduce the processor heat generation. The Intel Speedstep functionality remained enabled for the duration of the testing to get realistic CPU idle performance conditions.
Board voltage settings were configured as follows:
- CPU Core Voltage – 1.25
- CPU Input Voltage – 1.90
- DRAM Voltage – 1.65
- CPU Ring Voltage – 1.125
- CPU SA Voltage Offset – +0.100
- CPU IO Analogue Voltage Offset – +0.100
- CPU IO Digital Voltage Offset – +0.100
- PCH Core Voltage – 1.30
- PCH PLX Voltage – 1.75
The Hawell platform has proven time and again very good at testing cooler performance in its overclocked configuration because of the amount of heat the processor generates and teh small footprint of the CPU's die. The Reeven Okeanos was able to maintain system stability throughout the tests, but could not manage any runs without CPU throttling detected. In all three cooler configurations tested, the CPU throttling peaked at 8% with it going as high as 10% when using the dual fan LNA configuration. There was little difference between the runs with the triple fan configuration performing best out of the three Okeanos configurations. Note that no performance numbers were reported for the Brontes cooler because it could not maintain system stability during the overclocking runs.
Intel X99-based Haswell-E System Testing
Note that for the X99 Haswell-E system tests, results were reported for the Reeven Okeanos cooler only because of the Reeven Brontes lack of support for the platform.
CPU Stock Speed Testing
The CPU stock speed testing was conducted with the BIOS defaults set for the CPU and Turbo Mode disabled, equating to a 3.0GHz CPU speed, 2133MHz memory speed, 3.0GHz ring bus speed, and 100MHz base clock. The Intel Speedstep functionality remained enabled for the duration of the testing to get realistic CPU idle performance conditions.
The Reeven Okeanos cooler closed the performance gap significantly when tested with the stock speed Haswell-E processor. It matched performance with the top-rated Noctua NH-D15 cooler with the Okeanos operating in its triple fan configuration. The other two tested configurations performed just as strongly with performance slightly lagging that of the triple fan.
CPU Overclocked Speed Testing – Maximum air cooled speed
The CPU overclocked speed testing was conducted with known stable settings from a previous board review with Turbo Mode disabled, equating to a 4.25GHz CPU speed, 2666MHz memory speed, 3.5GHz ring bus speed, and 125MHz base clock. Also, the CPU-integrated graphics processor was disabled to reduce the processor heat generation. The Intel Speedstep functionality remained enabled for the duration of the testing to get realistic CPU idle performance conditions.
Board voltage settings were configured as follows:
- CPU Core Voltage – 1.275
- DRAM Voltage – 1.23
- All other settings set to Auto or stock settings
The Reeven Okeanos cooler was able to maintain its strong performance with the Hawell-E processor operating at overclocked speeds. The performance mirrored that of the stock speed Haswell-E with the triple fan configuration performing best and only slightly behind the Noctua air cooler. Both dual fan configurations performed behind the triple fan configuration with little difference between the stock and LNA configurations.
The true strengths of the Okeanos and Brontes coolers become visible when operating noise is taken into account. Both the Brontes cooler at stock and the Okeanos cooler in its LNA configuration are whisper quiet. In its stock configuration, the Okeanos cooler is audible above the system fans but is not noticeable over the GPU fan. In its triple fan configuration, the Okeanos can be heard over the GPU fan, but its noise profile tends towards a deeper sound instead of the high pitched squeal some units exhibit at higher noise profiles.