Intel/IBM/LBNL meeting on High Voltage DC (HV DC) Rack

bugenigmaSoftware and s/w Development

Oct 30, 2013 (4 years and 7 months ago)



meeting on
High Voltage DC (HV DC) Rack

November 4, 2005

Phone meeting


LBNL to review Intel/IBM input and will follow up via email.

Annabelle will provide spread sheet for architecture efficiency evaluation next week.

Jack will p
rovide study showing energy savings possible with HV AC distribution, if he
can locate it.

Annabelle/Pavan to check on possibility of using Intel data center for demonstration,
although they cannot provide support in setup and evaluation.

Annabelle/Pavan t
o confirm budget available for Intel support of project.

LBNL to organize a meeting for all interested industry partners before the end of the year,
place and time TBD.

Attendees :

Intel :

Annabelle Pratt,

power electronics engineer within
Digital Enterpr
ise Group (DEG),

architect for
high efficiency
server power architecture

Pavan Kumar, power electronics engineer within
Corporate Technology Group
CTG, architect for
high efficiency
server power architecture

Ed Stanford, power delivery engineer within Ente
rprise P
latforms and Services Division (EPSD)


Jack Lee
, Manager of High End Power Development, Systems Technology Development,
Product Power, Packaging and Cooling

Kevin Covi
Sr Technical Staff Member

in Jack’s group


Bill Tschudi
, projec
t lead for DC rack demonstration

My Ton, with
Ecos Consulting
, company focuses on energy efficient technologies and how to
promote them

Brian Fortenbery, with

Minutes :

Bill provided brief overview of project : It is part of an investigat
ion into power delivery efficiency
for high tech buildings, and is sponsored by the California Energy Commission, who have made
funds available for this demonstration project and who are also interested in additional
demonstrations. Initially focused on UP
S and PSU

power conversion efficiency,

draft reports are
available upon request. Details available at

Pavan presented the Intel proposal for a high voltage DC rack. The following were ma
discussion points :

IBM uses standard, off
shelf components for high voltage wiring, no custom parts
required. However, to obtain required spacing, they use a standard connector and skip
pins to achieve the required spacing at 350V. They also includ
e communication signals
in the high voltage cable.

Several questions regarding improvement in efficiency achieved by going to HV DC rack.
Intel/IBM agree that increased efficiency compared to traditional AC distribution in rack
should not be expected. Adva
ntages of HV DC rack relate to packaging, i.e. move
AC/DC out of high cost real estate area in server platform and move to low cost real
estate area at top of rack. This provides more space for silicon in the server platform. It
also reduces the heat load
in each individual server, making cooling of server platform
easier and
less costly. It may also reduce data center cooling requirements because
server platforms at top of rack will


inlet air

as heat load of servers below
them are reduced, a
ssuming that AC/DC can run at high inlet air temperature. Note that
total heat load of center will remain approximately the same.

A HV DC enable

rack will allow easy integration in a data center in which HV DC is
distributed. This will result in signific
ant efficiency increases since AC/DC in rack and
DC/AC in UPS no longer required. Th
e proposed

option allows flexibility

for end user

Losses in high voltage cables
negligible, but need to account for losses in electronic
circuit breakers.

LBNL would l
ike to do a paper study first. Annabelle will send a spread sheet used thus
far to estimate system efficiency, feedback on assumptions invited.

HV AC distribution in data center can also improve efficiency. IBM did study which
showed that in a particular c
ase, the end user could save $10,000 a year in utility costs.
Jack will send study if he can find it.

IBM mentioned that almost all server companies provide an option with a power supply
rated for 400Vac input for the European market, so a change to 400Vac

distribution in
American data centers may be a less painful transition than to 480Vac.

LBNL still needs to find a place to do demonstration. Annabelle/Pavan to check if
possible in Intel data center, but they do not have bandwidth to support the

and testing.

IBM interest in this project is to drive wider adoption of HV DC in rack, since right now it
is only


a small, high end segment of
server market. They are willing to act in
consultant role for this project, since they have working system
s and have been doing
this for 15 years. They could also potentially make hardware available to LBNL.

LBNL will organize another meeting with all interested industry partners, place and time
still TBD.