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June 21, 2007

USENIX 2007 Talk - Trends in Datacenter Efficiency

I presented a session at covering trends in datacenter efficiency. The attendees were a mix of HPC users (academic, render farm, search) along with high density corporate users and low density IT users. PDF of the presentation is available at:


Posted by cary at 5:23 PM

June 15, 2007

Critical Facilities Roundtable Meeting 06/15/07

I attended the Critical Facilities Roundtable meeting this morning at AMD's Sunnyvale campus.

I had hoped the first presentation on "Medium Pressure Overhead Ducting – Engineered Solutions" would have some useful data and include statistics on using outside air economizers. Unfortunately the presentation reviewed a single scenario with oversized supply ducts assisted with fans to provide proper airflow to distant ducts. There was little data backing up claims of increased fan energy efficiency.

The second discussion around EPA and legislation around datacenter efficiency was quite informative. Bill HR 5646 requires the EPA to report to congress by 6/22/07. The EPA must report on current datacenter trends and consider the energy implications of servers and datacenters. Bill Tschudi from LBNL believes the following:

EPA Energy Star Datacenter Energy Efficiency Initiatives

DOE Save Engergy Now Program

PG&E (local CA power company) sponsored the LBNL study on particulate and humidity when using outside air economizers. The brief rundown is that in most cases particulate and humidity can be easily kept within ASHRE guidelines while benefitting from air side economizers. Even though airborne particulate concentrations werre higher when the economizers werre operating, particulate levels quickly drop once external air intakes were closed. The speaker commented that even the particulate concentrations measured outside in the parking lot were below ASHRE guidelines. All sites in the study were in the San Francisco and Sacramento area. KC Mares from Yahoo noted that they are seeing much higher particulate in the Quincy area due to dust kicked up by local farmers. More great documents and data available on the LBNL website.

There an unscheduled discussion towards the end on energy reduction due to segregating the hot aisle from the cold aisle. In the study they prevented air mixing and segregated the aisles with plastic sheeting. The temperatures measured at the bottom/middle/top of the rack were 55F/68F/79F before the seperation, and 55F/57F/59F after seperation. Ideally they would have raised the building cold water supply to deliver 70-75F air but were unable to do so in this study. They measured a reduction in fan energy of 75%. Tellme is using ducted fan hoods in one of our datacenters to prevent hot/cold air mix and it works really well. Based on this study it would appear that the datacenter we occupy could significantly reduce fan energy if all cabinets (and other customers) were equipped with ducted racks or hot aisles

Upcoming CF or CF related meetings:

Posted by cary at 10:13 AM

June 7, 2007

Serge modular track for your listening (dis)pleasure

Several folks asked (demanded?) that I post some soundclips of my Serge in action. Below is a link to a 10 minute mp3 of the Serge with a free running patch and no sequencers or external controllers. Warning: I recorded this at 2am last night and didn't have my speakers on so there is _way_ too much low end in places.


I patched this up in just an hour or two Monday afternoon. Module/panel list is here:


Posted by cary at 4:24 PM

June 1, 2007

Worst synth paint job ever

Someone on Analogue Heaven asked "hey whats some of the craziest stuff you guys have seeen in terms of paint jobs and modifying the looks of a synth..."

Well, I'm pretty sure I own the worst looking ever:


That's an Oberheim Two Voice buried somewhere under that hideous paint job.

Posted by cary at 2:56 PM