Version 1.0 Data Center Storage Draft 4 Specification Proposed Approach
EPA held a discussion with stakeholders on September 5, 2012 to discuss the direction of Draft 4 of theVersion 1.0 ENERGY STAR Data Center Storage specification. This document summarizes the approach
EPA proposes to take for the Storage specification, including some significant proposed changes intesting requirements.
Summary
Version 1.0: EPA proposes to retain the homogeneous system testing requirements as outlined in Draft 3
but will introduce a set of modifications to reduce test burden in Version 1.0. EPA will also adopt Hot
Banding in this version. Draft 4 in early December, and a final document shortly thereafter.
TMVersion 1.1: When the SNIA Emerald Power Efficiency Measurement is further expanded to include
intelligent data placement (“auto-tiering”) and manually configured mixed drive systems testing, EPA willrapidly update the Storage specification to Version 1.1 to incorporate these changes.
Testing Burden Reduction Proposal for Version 1.0
EPA intends to move forward with the Draft 3 approach that optimal, maximum and minimum
configurations shall be submitted using only homogeneous storage device configurations. EPA continues
to believe that the strength of the current SNIA Emerald™ Power Efficiency Measurement specification,
as well as other publically available industry benchmarks, lie in assessing homogenous storage device
configurations. Further clarification on this topic can be found in the Homogenous vs. Heterogeneous
ENERGY STAR Storage Testing discussion document dated August 27, 2012, and which is publishedhere. The Draft 4 specification will include additional language to eliminate any confusion on permissible
configurations in Version 1.0.
EPA is proposing a set of revised approaches to reduce testing burden while maintaining adequate datacollection for Version 1.0. Setting levels in Version 2.0 based on data gathered in Version 1.0 is a priority;
therefore the optimal point data should drive the testing approach. EPA still intends to collect some data
outside of the optimal points to understand the scaling of work/watt in ENERGY STAR qualified storage
products with the goal of potential further reductions in future testing burden. The four areas of proposed
revision are provided below:
1. Allow pure SSD or Storage Class Media (SCM) to be utilized in the system without physicaltesting.
 EPA welcomes stakeholder physical test data on pure SSD/SCM systems to determine ifthey should be a separate system category in Version 2.0.
 Storage media that do not meet the storage device definition (e.g. SSDs used for cachingpurposes) are not affected by this proposal.
2. Require three physical testing points (optimal point, at least 40% smaller drive count than optimalpoint, at least 15% larger drive count than optimal point) for only one run per system for eachactive workload type submitted. Testing of additional drives for the same workload type will only
require physical data for the optimal point.
 EPA believes that systems will scale in similar fashion for all HDD types in a given
workload optimization, so less scaling test points are needed.
 Stakeholders will be required to report hot banding workload results.
 Stakeholder should select the highest volume sold HDD for the three physical testing
points.
Example: A stakeholder has a system that has three different HDD options for a transaction
workload optimized system. The stakeholder needs to complete three test runs for transaction
workloads, one for each drive type. The stakeholder should chose the highest selling volume

HDD to do the three physical test points described above, and only submit physical test data forthe optimal point of the other two drive options.
3. Only require one run of COM verification testing per system.
 Stakeholders will choose which physical test run to demonstrate COM functionality.
 Subsequent test runs will not need to proceed to this step after completing the active/idle
portion of the test run.
 EPA believes that COM features are a system property, and that if they are available forone storage device type, they will be available for all.
4. Rather than following the current 24 hour Ready Idle test requirements, EPA proposes thatstakeholders follow the Ready Idle procedure proposed in Version 2.0 of the SNIA Emerald™
Power Efficiency Measurement specification.
Version 2.0 Emerald Specification “Hot Banding” Adoption
EPA plans to use the proposed Version 2.0 SNIA Emerald™ Power Efficiency Measurement specification
currently under review as the base for testing in the Version 1.0 ENERGY STAR Data Center Storage
program. EPA will make revisions in the test method and the specification to harmonize with the revised
approach in the Version 2.0 Emerald specification where appropriate.
EPA would like to clarify its understanding that the Version 2.0 Emerald specification does not currently
solve the lack of intelligent data placement in mixed drive configuration testing. The EPA expects that
expansions or revisions to the test method guidelines and potentially the test method itself will likely berequired in order to incorporate mixed drive configurations into a potential Version 1.1 ENERGY STAR
Data Center Storage specification. The EPA is supportive of work directed toward developing andproofing such changes to allow for support of a Version 1.1 of the ENERGY STAR for Data Center
Storage specification.
Potential Version 1.1 ENERGY STAR Data Center Storage Specification Revision
EPA recognizes that mixed drive configurations are currently sold by several stakeholders and that thesesystems are in significant demand from their customers. EPA is supportive of industry efforts to expand
the current Emerald testing capability to incorporate intelligent data placement and manually configured
mixed drive systems. Once these changes to the test method are validated and effective, EPA will move
forward on a Version 1.1 revision. Testing instructions for mixed drive configurations will be added to theENERGY STAR Data Center Storage test method, and new language in the specification will allow for
mixed drive configurations to be used within the current “Systems Composed of Combinations of Optimal
Configurations” approach.
A revision from Version 1.0 to 1.1 will be much faster than the Version 1.0 development process, taking
no longer than a couple months to finalize.
Contacts
If you have any questions, please contact Robert Meyers, EPA, at Meyers.Robert@epamail.epa.gov or(202) 343-9923; or John Clinger, ICF International, at John.Clinger@icfi.com or (202) 572-9432.