Stock and Overclocked Temperature Testing
Cooler Testing Methods
To best gage the quality of the cooler under review and its effect on other components in the cooling loop, CPU, Chipset, VRM, and GPU temperatures were taken with the system idle and under load. To replicate 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 using the Furry E (GPU memory burner::3072MB) 3D Test, a 1280×1024 resolution, and an 8x MSAA Antialiasing setting. After each run, the system was shut down and allowed to rest for a minimum of 10 minutes to cool down. This procedure was repeated a total of 18 times – nine times for the stock speed runs and nine times for the overclocked speed runs.
Temperature measurements were taken directly from the CPU thermistors using CoreTemp v1.0 RC7 for the X99 testing. Because of the volatile nature of the 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.
Temperature measurements were taken from the board integrated thermistors to measure the Intel X99 Chipset and CPU VRM temperatures using the temperature monitoring functionality built into ASUS' Dual Intelligent Processors 5 software.
Temperature measurements were taken directly from the GPU thermistors using TechPowerUp GPU-Z v0.8.3. For both the idle and load temperatures, the highest recorded value in the application were used for the run. Note that the temperature values are reported as deltas rather than absolute temperatures with the delta value reported calculated as GPU temperature – ambient temperature.
To adequately measure the EVGA GTX 970 SC's cooler performance in SLI, performance testing was done for most scenarios with the cards liquid cooled using a modified configuration with the HeatKiller GPU-X3 GPU water block.
Note that the temperature values are reported as deltas rather than absolute temperatures with the delta value reported calculated as GPU temperature – ambient temperature. For all tests, room ambient temperature was maintained between 25-28C.
Stock Temperature 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. Chipset and VRM temperature testing was conducted at stock speeds with both air and liquid-based cooling. The graphics card temperature testing was conducted at stock speeds with liquid-based cooling with values reported for each individual card for comparison purposes.
Chipset and VRM Performance
With the Bitspower liquid cooling installed to the board, performance was best with the blocks in-line with the CPU only. Adding the GPUs into the cooling loop increased load temperatures a few degrees more. The best performance was seen with the VRM temperatures since the Intel X99 chipset really does not generate much of a heat load.
The effect of the Bitspower block on CPU temperatures was minimal at best with the system running at stock setting. Even with the VRMs and GPUS dumping heat into the system, the deltas between the lower temperatures with the GPU removed from the loop is a mere 3C.
The addition heat load introduced by the Bitspower blocks has negligible impact on the GPUs temperatures, raising measured temperatures by 1C at idle and under load.
The system overclocked speed testing was conducted with the highest achievable stable settings from a previous board review with Turbo Mode disabled, equating to a 4.375GHz CPU speed, 2666MHz memory speed, 3.5GHz ring bus speed, and 125MHz base clock. It was found that running with GPUs in SLI mode necessitated lowering the overclocked board speed from 4.5GHz to 4.375GHz to achieve reliable system operation. The Intel Speedstep functionality remained enabled for the duration of the testing to get realistic CPU idle performance conditions. Chipset and VRM temperature testing was conducted at stock speeds with both air and liquid-based cooling. The graphics card temperature testing was conducted at stock speeds with liquid-based cooling with values reported for each individual card for comparison purposes.
Board voltage settings were configured as follows:
- CPU Core Voltage – 1.325
- System Agent Voltage – 1.225V
- DRAM Voltage – 1.23
- All other settings set to Auto or stock setting3s
GPU settings were configured via EVGA Precision X 16 profile settings as follows:
- GPU Clock Offset, card 1 – +100MHz
- GPU Clock Offset, card 2 – +115MHz
- Memory Clock Offset – +500MHz
- GPU Voltage Overvoltage – +37mV (Max)
- Power Target – 110% (Max)
- GPU Temperature Target – 91C (Max)
- Fan Preset – N/A
- GPU Boost Clock Speed – 1468MHz
- Memory Speed – 1977MHz
- GPU voltage, card 1 – 1.1870V
- GPU voltage, card 2 – 1.2000V
Chipset and VRM Performance
With both the CPU and GPUs running overclocked, the Bitspower blocks have a much more noticeable effect on the VRM temperatures. The VRMs run 10C cooler on average compared to operating with the stock air cooler. While the chipset load temperatures do not change in comparison to the air cooled values, the idle temps are lower with the Bitspower block.
The Bitspower blocks' effects with an with the overclocked system mimic those seen at stock speeds. Temperatures increase by 2-4C on average with the Bitspower blocks adding heat to the cooling loop.
The effects of the Bitspower blocks on GPU temperatures remain minimal, similar to the temperature increases seen with the system running at stock speeds.