blog.retrosynth.com http://blog.retrosynth.com/ en 2008-09-18T16:25:55-08:00 Intel Air Side Economization Study http://blog.retrosynth.com/archives/2008/09/intel_air_side.html Intel announced the results of a ten month long study of air side economizers at one of their New Mexico facilities:

Intel set up 448 blade servers in each of two 500sqft rooms in a modular building space, totalling over 100kw of critical load per room. They used a commercial ducted DX packaged unit for cooling one of the spaces, and the same make and model cooling package using 100% outside air for the other space. The unit drawing 100% outside air was configured to start cooling if the intake air exceeded 90F. That's pretty warm even for high air flow servers.

Server failure of the outside air room was almost double that of the closed loop room: 4.46% vs 2.45%. Intel didn't find the increased failure rate to be an issue but I'm sure their server vendors warranting the equipment would disagree.

Bill Tschudi and others at Lawrence Berkeley have done a good bit of research on particulate in datacenters using air side economizers. It's available here:

]]> Technology cary 2008-09-18T16:25:55-08:00 IBM Announces iDataPlex line http://blog.retrosynth.com/archives/2008/04/ibm_announces_i.html The press folks at IBM have jumped the gun and posted a video of their new iDataPlex line in advance of the official announcement tomorrow morning. The video on their press site does little to demonstrate how it's any different that what is currently available on the market. There are a few glimpses of the actual hardware 1 minute and 25 seconds into the 140MB windows media file.

http://ibm.com/press/video/iDataPlex_FINAL.wmv

Hopefully there will be better details of the product line tomorrow. From the brief glimpses in the movie it looks like yet another Rackable clone.

]]> Technology cary 2008-04-22T18:53:47-08:00 Alesis ModFX Bitrman Control Voltage Mod http://blog.retrosynth.com/archives/2008/04/alesis_modfx_bi.html

Here's a video of an Alesis Bitrman that I modified for external control voltage input. I think it takes an already good sounding effects box and allows it to really shine. While it's driven by a quantized voltage source in the video it's exceptionally good with a non-quantized source such as a Serge TKB. Then you can tune the the frequency shift amount, or ringmod sidebands, to be in tune with the pitch of that particular step. Loads of fun.

]]> Music cary 2008-04-20T21:51:11-08:00 World Class Datacenter? http://blog.retrosynth.com/archives/2008/03/world_class_dat.html It was interesting to see a picture of my handiwork on the March 3 issue of InformationWeek. The photo appears to be 3 years old based on the servers shown in the racks. I'm sure Tellme/Microsoft didn't intend for this picture to ever be public.

]]> Technology cary 2008-03-20T19:00:14-08:00 Critical Facilities Roundtable Meeting 03/12/08 http://blog.retrosynth.com/archives/2008/03/critical_facili_1.html I attended the Critical Facilities Roundtable meeting on Wednesday, hosted at the Altera campus.

The first 20 minutes were for announcements and other meeting business:

  • Charles suggested we pursue research using the power grid as a generator load bank instead of resistive on site load banks. This of course requires power company cooperation and with PGE in the room it put some pressure on them.
  • LBNL announced they will be releasing a datacenter profiling tool in May.
  • LBNL will release the results of the LBNL and Sun "Chill Off" this summer.
  • On Friday April 11 there will be a tour for interested parties of a supposedly Platinum LEED carbon neutral datacenter in Sonoma Mountain Village.

Altera and PGE then discussed the cold aisle containment retrofit of the Altera datacenter in building 3. The datacenter consists of 8-10 rows of 6-8 cabinets with each hot aisle and cold aisle enclosed on one side by a wall. There were four pre-existing air handlers in the room, two DX CRACs and two water CRAHs.

They gathered the following data:

  • Temperature probes on the inlet and discharge side of the CRACs and CRAHs
  • Four temperature probes in each cold aisle
  • Current taps on the CRAC condensers to measure load
  • Power draw of each rack

The data showed that:

  • Only 40% of conditioned air was used to cool the servers
  • They were conditioning 2.6 times more air than necessay
  • Server face temperature varried from 68F to 77F
  • CRAC delta T was only 12F to 18F

Based on the gathered data Altera believed they could benefit from hot aisle containment. They acheived this by:

  • Installing blanking plates on the fronts of all server racks to fill empty rack spaces
  • Adding clear vinyl strip curtains on the aisle side of each cold aisle
  • Fabricating sheet metal barriers between the tops of the racks and the drop ceiling
  • Removing perf tiles from the hot aisles
  • Ensuring adequate sprinkler head coverage (two per aisle) in both the hot aisles and cold aisles
  • Installing APC InRow RC water cooled air handlers in the high density rack line ups

After the retrofit Altera was able to cut energy use by 44.9KW with an annual savings of 393MWHrs.

Some notes from the Q&A session:

  • Altera used polyurethane foam between the metal partition wall and the tops of racks to seal up any open areas
  • The APC InRow units are fed by building chilled water and each have their own VFDs for fan speed control and well as electronically operated balancing valve
  • The main 30 ton CRAH in the room is used to handle primary cooling and humidity control
  • If segregation wall is deemed a temporary structure then there is no requirement to refit the sprinkler heads
  • Altera will be using strip curtains with fusible links above the racks in their next build to avoid relocating sprinkler heads
  • Sprinklers were already in place above the interstitial area (drop ceiling)

Following the Altera presentation Validus DC gave a presentation on their high voltage DC distribution scheme. Since I've seen this presentation before I didn't take notes. They did mention they have a large datacenter getting ready to deploy multiple 2.5mw pods/modules/colos in their next datacenter. I can only assume this to be one of the big three search engine properties. While there certainly are benefits to Validus's 540V and 48V distribution strategy, I'd rather see 380V DC distribution all the way to each server instead of stepping down to 48V at the row or rack level. This would cut out another stage of conversion and associated losses.

]]> Technology cary 2008-03-17T07:19:33-08:00 Oberheim Two Voice demo http://blog.retrosynth.com/archives/2007/09/oberheim_two_vo.html After wasting a couple days on the aforementioned Opcode Sonicport project I was finally able to import audio from my DAT player to replace the woeful audio the camera's built-in mic captured. I recorded 15 minutes of various Oberheim Two Voice noodling to show off what the combination of two SEMs and a sequencer can do. I broke the video up into segments. This is the first of several.

]]> Music cary 2007-09-22T23:29:47-08:00 Opcode Sonicport Info http://blog.retrosynth.com/archives/2007/09/opcode_sonicpor.html I picked up an Opcode Sonicport SPDIF to USB audio interface many years ago. The Windows 98 driver and config application were always a bit sketchy and didn't get a chance to improve as Gibson purchased then disbanded Opcode. As far as I know there was never a release of the config app that ran under Windows 2000 or XP. Since I didn't like the idea of keeping a Win98 host around for eternity I poked at the internals to see if it's possible to change from analog to digital I/O without writing a config app.

The device uses a Philips/NXP UDA1335H USB to analog and I2S bridge. SPDIF to I2S conversion is handled by a Crystal CS8425. The UDA1335H uses an 8051 derivative for housekeeping booting its code from an external EPROM and storing parameters to a 24C16 serial EEPROM. I've thought of several elegant ways to address the config issue but for now I'm just manually swapping 24C16 EEPROMs after having stored the different configs I used.

The original Opcode Sonicport/Datport driver utility disk for Windows 98 is available here.

Images both an analog config and a digital 44.1k 16 bit config available here.

]]> Music cary 2007-09-22T23:14:45-08:00 Bay Area Analogue Heaven Gathering http://blog.retrosynth.com/archives/2007/09/bay_area_analog.html I just returned from the bay area Analogue Heaven gathering at the 21 Grand gallery in Oakland. A good time was had by all. My pictures are here:

http://www.retrosynth.com/slideshow/20070909_baah/

Additional photos by Jim Whittemore here:

http://synchro1.smugmug.com/gallery/3454091

and Jon Schatz here:

http://www.divisionbyzero.com/ahcali2007/

]]> Music cary 2007-09-09T21:35:07-08:00 USENIX 2007 Talk - Trends in Datacenter Efficiency http://blog.retrosynth.com/archives/2007/06/usenix_2007_tal.html 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:

http://www.tinkthank.com/public/usenix07_datacenter_efficiency_trends.pdf

]]> Technology cary 2007-06-21T17:23:15-08:00 Critical Facilities Roundtable Meeting 06/15/07 http://blog.retrosynth.com/archives/2007/06/critical_facili.html 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:

  • change will accelerate with top down intervention
  • all areas of datacenters need to be addressed
  • objective, credible information is needed
  • prescriptive approaches won't work due to rapid change in industry

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:

  • 7/9/07 - Presentation by Synopsys on Group Computing, also talk on Massive Array of Idle Disks
  • 7/12/07 - Updates and Standards meeting @ Intel
  • 7/13/07 - DCD
  • 7/19/07 - Alternative AC and DC power distribution strategies - http://www.svlg.net/
  • 7/20/07 - Next Critical Facilities Roundtable meeting, location TBD
]]> Technology cary 2007-06-15T10:13:28-08:00 Serge modular track for your listening (dis)pleasure http://blog.retrosynth.com/archives/2007/06/serge_modular_t.html 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.

http://www.retrosynth.com/mp3/m3u/Serge%20Demo%2020070606.m3u

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

http://www.retrosynth.com/gear/serge/

]]> Music cary 2007-06-07T16:24:48-08:00 Worst synth paint job ever http://blog.retrosynth.com/archives/2007/06/worst_synth_pai.html 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:

http://www.retrosynth.com/gear/tvs/painted/painted_tvs_001.jpg

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

]]> Music cary 2007-06-01T14:56:29-08:00 MiniROM for the Blacet Miniwave http://blog.retrosynth.com/archives/2007/04/retrosynth_mini.html Jason Proctor asked me a while back to burn some PPG wavetables into some ROMs for the Blacet Miniwave. I was a little concerned about how he was going to sweep through the 64 waves per bank. This isn't real easy as the Miniwave only has 16 waves per bank whereas the PPG had 64 waves per bank. I opened my big mouth and said it wouldn't be that difficult to build a PCB with surface mount FLASH that crams all of the PPG wavetables into a nice small plug and play package. With a little bit of swizzling of the address lines of the bank and wave A/D converters it'd be trivial to drive with no external CV processing.

The end result is a 1.2" x .7" PCB that has 32 banks of 64 waves each, which allows for smoother transitions between waves than a stock Miniwave with the previously available ROM waves. It installs in a socket just like a regular ROM but has four wires that are tack soldered to the back of the board to pick up extra bits of resolution from the wave and bank A/Ds. Pictures of the first unit are here:

http://www.retrosynth.com/gear/minirom/minirom_rev1/

I've built five beta units (in addition to a single wire wrap prototype) and they work just fine although my intended method for programming them didn't pan out. I'll have to come up with another scheme for bypassing the onboard logic while programming the FLASH and spin another board.

I have a demo up on youtube:

http://www.youtube.com/watch?v=qm9m_G0efdI

]]> Music cary 2007-04-09T09:43:36-08:00 Don Martin era Moog modules http://blog.retrosynth.com/archives/2007/03/don_martin_era.html There don't seem to be any photos of the Don Martin era Moog modules so I posted some pictures at my site below. NO, THEY'RE NOT FOR SALE!

http://www.moogmodular.com/

The construction is surprisingly good. Circuit board artwork and component layout is similar to RA Moog modules. Where Don really screwed up was the truly abysmal power supply with so much ripple that the oscillators would sync even when tuned to fifths or better. Unfortunately I didn't have these back in 2002 when Peake and Konkuro and I A/Bed original RA Moog with synth.com stuff.

Below is a list of modules Don Martin / Moog Music claimed to be manufacturing. I have not personally seen all of these modules so cannot speculate if all were manufactured. I have (1) 9501, (1) 9501A, (2) 9501B, (2) 9502, (1) 9503A, (1) 9504A, (1) 9505, (1) 9510, (2) 9511, (2) 9800R, and (1) blank panel. I think the original modules released were limited to those available for copying from Ohio University's system, which I should mention was never returned.

9501 Voltage Controlled Oscillator
9501A Oscillator Controller
9501B Oscillator
9502 Voltage Controlled Amplifier
9503 Random Noise Generator
9504A Voltage Controlled Lowpass Filter
9504B Voltage Controlled Highpass Filter
9504C Filter Coupler
9505 Reverberation Unit
9507 Fixed Filter Bank
9510 Power Supply
9511 Envelope Generator
9511A Dual Trigger Dealy
9512 Envelope Follower
9514 Extended Range Fixed Filter Bank
9521 Voltage Controlled Oscillator
9521A Oscillator Controller
9521B Oscillator
9560 Standard Interface
9591 Filter / Attenuator Panel
9594 Jack Multiples Panel
9595 Ring Modulator
9596 Sample & Hold
9598 Mixer
9599 4 Channel MIDI-CV Convertor
9800R Eight Unit Rack Mount System
9801P Cable Pack

]]> Music cary 2007-03-30T01:24:19-08:00 Back from AHMW 2007 http://blog.retrosynth.com/archives/2007/03/back_from_ahmw.html Just got back from Analogue Heaven Midwest 2007 in lovely Lagrange Indiana. Thanks to Andrew for hosting and organizing. Pictures here:

http://www.retrosynth.com/slideshow/20070324_ahmw/

I've posted some videos to youtube:

http://www.youtube.com/results?search_query=retrosynth+ahmw&search=Search

I have some audio from the event on DAT but I'll probably never get around to dumping it into a computer and editing.

]]> Music cary 2007-03-26T15:50:15-08:00