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   I did an entire set of photos with Courtney under improvised lighting conditions.  I wanted to play with some high-contrast photos but ended up hating most of the results.  A couple of the pictures are alright, but I had lot of strange colored shadows and harsh lines.  Can't win them all I guess.
   A month or two ago I installed a motion switch in our mudroom.  People kept leaving the light on all the time and the motion switch fixed that problem.  However, the florescent lights in the back were ancient.  One of the fixtures didn't turn on at all, and the other was having difficulty starting.  With the motion switch constantly switching power on and off the lights soon were unable to start.  So I decided to upgrade the setup and install LED florescent replacement bulbs.  This required the LED bulbs and new electronic ballasts.  Now we have a lot of instant light.
   The mudroom is one of several lights replaced with motion lights.  I picked up a motion sensing LED bulb online and tried it in the front porch early in the year.  It worked so well I picked up several more.  Now there is a motion sensing LED in the fixture outside the porch, in the porch, and in the double-doors between the porch and living room.  We have a camera watching the front porch and had been leaving the light on so the camera could see what was going on.  Since the lights are now motion activated they don't need to stay on and the camera will only see where there is something to be seen.  The last place I added motion lights was in the basement by the washer and dryer.  This was an other area lights were often left on, but the problem now solved.
   Post-Cinco cleanup wasn't as bad as it has been in the past.  We kept the fire going all night as several of the traveler kids slept by it to keep warm.  In the morning the fire was built back up and breakfast cooked on it.  So by cleanup time we had a good fire already going.  The two day festivities burned almost an entire trees worth of wood.  We had a dead Elm tree that was cut down just before the party and burned though most of it.  Cleanup had a lot of twigs, bark, and things like paper plates and cigarette butts that could burn.  So all went onto the fire.  The backyard was looking good fairly quickly.  Inside mainly just required mopping as little time was spent in doors.
   The first day of Cinco de Mustache, our groups very large annual event we started hosting at Elmwood Park.  Cinco weekend always seems to fall on the coldest weekend in May and this year was no exception.  There was rain forecast for the late in the evening and we had an outdoor pause of about 3 hours.  Nonetheless we had a very large turnout the first day.

May 04, 2017

Comparison of single-board computers and PCs

Did some speed testing to compare my various single-board computers to some personal computers.

System CPU OS Bits Speed (GHz) Threads Time (mins)
Raspberry Pi 3 ARM Cortex-A53 Yocto 64 1.2 4 145.38
Odroid C2 ARM Cortex-A53 Ubuntu 16.04 64 1.5 4 48.28
Odroid U3 ARM Cortex-A9 Ubuntu 14.04 32 1.7 4 288.67
Dimension E520 Intel Pentium D 820 Mint 14 64 2.8 2 179.92
Latitude E6530 Intel Core i7-3540M Win7 64 3.0 4 28.26
Laditude E5450 Intel Core i5-5300U Win10 64 2.3 4 35.56

These tests were performed using my threaded prime number counter which offers a 100% CPU for a given number of cores. The single-boards hold their own even against the PCs clocked at much higher speeds. The slowest system on the list is the Sun-Dragon which is the 32- bit Cortex-A9 Odroid U3. The fastest system is my work laptop, the Core i7 Latitude E6530. However what I find interesting is that at half the clock speed and a fraction of the total power the Emerald Dragon, a Cortex-A53 Odroid C2, is less half as slow. That is, if the Emerald Dragon were clocked at 3 GHz it would have out performed the Core i7.

Another thing to note is all the single board computers are RISC machines and all the PCs CISC. What this generally means is that the RISC computers require more operations to do the same task, but can do those operations faster whereas a CISC machine can combine steps in a single instruction. Thus one expects that with a RISC and CISC machine clocked at the same speed, the CISC machine would have better performance. Clearly there are other factors at play here, such as memory speed, cache, instruction pipelining, etc.

Right now the Cortex-A53s are the top-of-the-line for ARM based computers. While they cannot yet compete with desktop machines, the gap is closing. Having always been an ARM fan this is encouraging and maybe one day I will have a screaming fast ARM-based PC.

   Picked this device up the other day.  It has media controls for a Bluetooth device.  I use my phone all day at work to listen to music, but switching tracks is rather irritating because of how the screen is oriented.  This is a great improvement.  In addition, I can switch tracks while driving and cycling. 

At work I have been working on a project that uses Yocto Linux. When it looked likely we were going to get the project, I decided to see about building Yocto for a Raspberry Pi. I never got it to work, but I think I know why. My failures were due to the fact I incorrectly identified which version of the Pi I had. I had been building for a Raspberry Pi 2 but that SBC was actually version 1.2, not a 2. The Pi 2 has either a 32-bit ARM Cortex-A7 or a 64-bit ARM Cortex-A53. The Pi 1.2 has a 32-bit ARM11. These processors not the same at all and the fact the build even generated a test pattern is impressive.

Over the weekend Pluvius picked me up a Raspberry Pi 3 which is the latest model based on a 64-bit Cortex-A53. So I decided to try a Yocto build for that. Using the Noire Dragon, my 64-bit quad-core laptop, the build completed in 6 hours. This time when I loaded the image, it worked. I was able to log in and play the movie Big Buck Bunny, confirming the build with functional.

The Pi 3 is fast and even playing a 1080p movie barely stresses the CPU.