Version 2.0 Computer Servers Draft 3 Test Method Comment Responses

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Test
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Stakeholder Comment

DOE Response

DC servers with input voltages in the range of 360 V – 400 V isnot uncommon. The stakeholder recommends that this dc
voltage level be specific in the test method.

The Final Draft ENERGY STAR Specification does not include dc
powered servers in its scope; therefore, DOE has excluded dc
powered servers from the Final Draft ENERGY STAR Test Methodfor Computer Servers (Rev. Dec‐2012).

The Test Method for Servers should include the option of 208 V
three‐phase AC power specifications for three‐phase poweredservers.

Because it is possible that some servers may only be powered bythree‐phase AC power, DOE has updated Table 1 and Table 2 insection 4.A) of the Final Draft ENERGY STAR Test Method for
Computer Servers (Rev. Dec‐2012) to include 208 V for three‐phase powered servers.

Voltage standards of 100 V, 110 V, 200 V, 208 V, 220 V, 230 V,and 400 V ± 5% should be specified in the Test Method to foster
international adoption of the test method for servers.

DOE agrees with this comment and has updated Table 1, Table 2and Table 3 of the Final Draft ENERGY STAR Test Method for
Computer Servers (Rev. Dec‐2012) to include single phase and 3‐
phase voltage and frequency requirements for international
standards. The values specified are consistent with the Server
Efficiency Rating Tool (SERT) Run and Reporting Requirements.

Voltage Specification

Voltage Specification

Voltage Specification
The capitalization of the abbreviations for alternating current (ac)There is an inconsistency in the capitalization of the terms ac andand direct current (dc) is now consistent throughout the Final
dc in the specification, test method and Power and Performance
Draft ENERGY STAR Test Method for Computer Servers (Rev. Dec‐Data sheet. We recommend that “AC” and “DC” be used to2012), the Final Draft ENERGY STAR Specification for Computer
represent alternating current and direct current respectively.
Servers, and all related documents.
Editorial
To be consistent with SERT’s requirements, DOE has modified thelower limit of the ambient temperature requirement to 20 °C.
The minimum temperature should be 20 °C in alignment with theHowever, DOE believes that setting the ambient temperature
SERT requirements. Minimum temperature of 18 °C as specified
upper limit to a manufacturer‐documented value may not allow
in the Draft 3 Test Method for Servers could increase hours offor consistent testing and comparison between different products.
chiller operation and increase energy use in air conditioning. InAs such, DOE has maintained the maximum ambient temperature
addition, 18 °C is not comfortable for human work conditions.
at 30 °C in section 4 B) of the Final Draft ENERGY STAR Test
Method for Computer Servers (Rev. Dec‐2012).

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Version 2.0 Computer Servers Draft 3 Test Method Comment Responses

6 SummaryTestSetupAmbient Conditions

DOE also believes that the relative humidity (RH) conditions
specified by manufacturers will fall between 15% ‐ 80% RH, as
Also, the ambient temperature upper limit and the relative
specified in the Draft 3 ENERGY STAR Test Method for Computer
humidity should be within the documented operating conditions
Servers (Rev. Aug‐2012). As such, DOE has maintained the 15% ‐of the UUT.
80% RH range in the Final Draft ENERGY STAR Test Method forComputer Servers (Rev. Dec‐2012).

Section 4.D) of the Draft 3 Test Method should be replaced bysection 4.3 of SERT Design Document in order to maintainconsistency between these two test methods.

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Test
Setup

Test
Setup

DOE agrees with this comment and section 4.D) of the Final Draft
ENERGY STAR Test Method for Computer Servers (Rev. Dec‐2012)is consistent with section 4.3 of SERT’s Design Document for therelease candidate. The update to this section includes:∙∙∙Modifications to the power analyzer accuracy specifications
Configuration information for the SERT controller system
Referencing the SERT Design Document

Power Analyzer
The language in section 4.D)6) should be updated to “including DOE agrees with this comment and section 4.D)6) of the Final
any external shunts, SHALL MEET THE FOLLOWING CRITERIA” for Draft Test Method for Computer Servers (Rev. Dec‐2012) is now
clarity purposes.
consistent with the stakeholder’s recommendation.
EditorialTest
Conduct Storage

EPA is not excluding qualification for systems that do not comewith installed storage devices. In support of qualifying suchsystems, Section 5.1.F) of the Draft 3 ENERGY STAR Test Method
Reword section 5.1.F) of the Test Method for Servers to reflectfor Computer Servers (Rev. Aug‐2012) provides instructions on
the fact that EPA is not allowing qualification of systems with no how to test computer servers that do not include pre‐installed
installed Hard Disk Drive (HDD) or Solid State Drive (SSD)
storage devices. The intent of this section is to provide instruction
on how to test these products, not explain coverage of products.
Thus, DOE has not modified this section of the text in the Final
Draft.

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Version 2.0 Computer Servers Draft 3 Test Method Comment Responses

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Test
Conduct UUT Preparation

Test
Method Active State

Test
Method Idle State

Test
Method Idle StateIn Draft 3 of the test method for servers, DOE states that power
supplies and cooling fans used for chassis function andredundancy for populated power domains in a half chassis blade
Redundancy can vary based on a customer’s needs, and for someconfiguration shall not be removed for testing purposes.
models, there may not be a “standard offering". Additionally,redundant components may be ordered separately for some
Update the language in section 5.2.C)3)c)iii) of the Draft 3 Test
systems. In light of this, DOE has changed the language regarding
Method for servers to state that power supplies and cooling fansredundancy. Section 5.2.C).3).c).iii) of the Final Draft ENERGY STAR
used for chassis function and redundancy for populated power
Test Method for Computer Servers (Rev. Dec‐2012 ) now requires
domains in a half chassis blade configuration shall not bethat all blade server redundant power supplies be configured as
removed where redundant power is a standard offering for theper manufacturer recommendations.
product. There are a few cases when some blade servers may be
shipped with a single power supply, even when there are slots
for redundant supply.
DOE agrees with this comment. Section 4 of the Final Draft
The manufacturer specific workload should be replaced withENERGY STAR Test Method for Computer Servers (Rev. Dec‐2012)
SERT. In addition, the ENERGY STAR Test Method for Servers
has been harmonized with sections 4.1, 4.2 and 4.3 of the SERT
should be made consistent with SERT with references to the SERT
Design Document Release Candidate 1 (RC1). Note that these
Design Document and SERT Run and Reporting tools in the test
documents are for SERT’s Release Candidate and they may
method.
modified with the final release of SERT.
One manufacturer was concerned with the 5 minute idle power Reporting the lowest of the three 5 minute idle measurements willmeasurement. Some of their server offerings perform memory
not capture the power consumption of the server during themaintenance activities for up to 3 minutes. Depending on where intermittent maintenance cycles initiated by the server. Thus, thethe 5 minute measurement would land, the measured idle power reported values may underrepresent the long run average of this
could vary significantly.
server in the idle state.
The manufacturer proposes that the idle test should take up to
three 5 minute measurements over a 15 minute period, with thelowest of the three measurements reported as the idle poweruse of the SUT. They believe that this method will enable
identification and removal of power impacts on idle mode ofoperation driven by intermittent maintenance activities such as
memory scrubbing and would provide consistency in themeasured power values.

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DOE’s approach includes the effect of the maintenance cycles toprovide a representative power measurement. As such, DOE has
increased the idle power measurement period from 5 minutes to
30 minutes. A longer idle measurement period will average out
the increased power consumption caused by the maintenancecycle.