ATP Power Usage Effectiveness & Efficiency 2

Question 1

A data center reports a PUE of 1.0. What does this indicate?

Accepted Answer

All power is used exclusively by IT equipment with zero overhead

Answer

A PUE of 1.0 is theoretically perfect, meaning 100% of power goes to IT equipment with no overhead losses.

Question 2

Which metric is the mathematical reciprocal of PUE?

Accepted Answer

DCiE (Data Center Infrastructure Efficiency)

Answer

DCiE equals 1/PUE and expresses infrastructure efficiency as a percentage, where higher values are better.

Question 3

A colocation facility has total power draw of 8 MW and IT load of 5 MW. What is the PUE?

Accepted Answer

1.6

Answer

PUE = Total Facility Power / IT Equipment Power = 8 MW / 5 MW = 1.6.

Question 4

What does a PUE measurement taken only at peak summer load fail to capture?

Accepted Answer

Seasonal variation in cooling efficiency across the full year

Answer

PUE varies with ambient temperature and load, so a single peak-load measurement misses the more efficient winter and shoulder-season periods.

Question 5

Which of the following is NOT included in the IT equipment power denominator when calculating PUE?

Accepted Answer

Computer room air conditioning (CRAC) units

Answer

CRAC units are facility infrastructure overhead, not IT equipment, so they belong in the total facility power numerator only.

(ATP) Accredited Tier Professional Certification (Cooling & Refrigeration) Practice Test