Section 11 - Thermal Test Basics
The topic of processor temperatures can be very confusing. Unfamiliar terminology and specifications, misconceptions and widespread misinformation, conflicting opinions and inconsistent test procedures leaves users uncertain of how to properly check cooling performance. Moreover, when load and idle test conditions are not clearly defined, results can be highly misleading.
• Full load is a steady-state workload at 100% TDP.
• Idle is a state of minimal activity at 1% Utilization.
In this Part of the Guide, load and idle test conditions are explained, as well as how TDP and AVX relate to thermal testing. By replicating test conditions that conform to Intel's Datasheets, valid baseline Core temperatures can be found. Applying a methodical approach minimizes variables so results will be consistent, repeatable and easier to compare. Here's how it's done:
There are three major test variables. When managed correctly, two variables become points of reference which are needed for valid test results. The remaining test variable determines your thermal performance at 100% workload and at idle. Methods for properly conducting thermal tests include managing these variables:
• Environment - Intel tests their processors in a tightly controlled environment. Variables in Ambient temperature can be normalized to 22°C, which is a point of reference. Normalizing is explained under the Setup in Section 12.
• Hardware - Intel tests their processors on an open bench without a case. Variables in thermal performance can be minimized by removing case covers and manually setting all fans and pump (if liquid cooled) to 100% RPM.
• Software - Intel tests their processors using a steady 100% TDP workload. Variables in test software can be eliminated by using Prime95, which is a point of reference. The Small FFT's test without AVX conforms to Intel's Datasheets.
The Datasheets provide guidelines needed for a coordinated and methodical approach, so it's important to be specific. "Full load" is a popular but non-specific user term which could mean anything. Games, apps, streaming, rendering, transcoding and most utilities have partial, fluctuating workloads with fluctuating Core temperatures that are not well suited for testing thermal performance.
“Stress” tests vary widely and can be characterized into two categories; stability tests which are fluctuating workloads, and thermal tests which are steady workloads. Prime95 v29.8 Small FFT's (AVX disabled) is ideally suited for testing thermal performance, because it conforms to Intel's Datasheets as a steady 100% workload with steady Core temperatures. No other utility can so closely replicate Intel's thermal test workload.