How Long for Long Pi – Part 2

In a previous blog post I considered how I might benchmark performance of different computers to understand how they compare across processor generations and maybe in the future across major architectures.

After experimenting with some different Python code, I found a version that is very consistent in it’s performance, seems to run on 1 core of a multi-core processor and can run on Windows and Linux. Here’s the version I am using for calculating Pi to 100K. I sourced it from this Stack Overflow thread.

#-*- coding: utf-8 -*-

# Author:    Fatih Mert Doğancan
# Date:      02.12.2014

# Timer Integration 18-Jun-22 by Jim Reed

# Timer function Start
import time

start = time.time()
print("Dogancan - Machin 100,000 Digits Pi Calculation Start")

#Original Calculation Code goes here

def arccot(x, u):
    sum = ussu = u // x
    n = 3
    sign = -1
    while 1:
        ussu = ussu // (x*x)
        term = ussu // n
        if not term:
        sum += sign * term
        sign = -sign
        n += 2
    return sum

def pi(basamak):
    u = 10**(basamak+10)
    pi = 4 * (4*arccot(5,u) - arccot(239,u))
    return pi // 10**10

if __name__ == "__main__":
    print (pi(100000)) # 100000

# calculation code code ends
# timer reports

end = time.time()
print("Dogancan - Machin 100,000 digits elapsed calculation time")

I expect to share all my raw data as I get it more in shape, but I am definitely getting some good first impressions. Let’s look at a summary of the tests on 5 machines so far, running Pi to 100K places using the code above on Python in a command prompt / terminal shell.

My PC NamePC TypeOSPi to 100K in X Seconds
(Avg 3 Runs)
TelstarRaspberry Pi 3Raspbian148.395
EdisonRaspberry Pi 4 8GBRaspbian111.263
TeslaIntel i7-7th Gen DesktopWin 1112.997
TeslaIntel i7-7th Gen DesktopUbuntu 2010.960
Charlie DukeIntel i7-8th Gen LaptopWin 1113.342
Charlie DukeIntel i7-8th Gen LaptopUbuntu 2011.627
MarconiIntel i7-12th Gen DesktopWin 116.152
MarconiIntel i7-12th Gen DesktopUbuntu 205.352

No surprise here on machine power. The more powerful the machine, the faster it processed. Now, I don’t think I have enough samples or data to draw a strong conclusion, but on the machines where I could run Ubuntu and Windows, Ubuntu outperformed Windows by at least 12% when averaged across the three runs.

Now let’s step it up an order of magnitude. How long will it take these machines to calculate Pi to 1 Million places. I used the same Python script, just changed the variable. Note on this run because of the long run times, I only ran the Raspberry Pi tests ONCE, the 3 other PC’s show an average of 3x runs.

My PC NamePC TypeOSPi to 1 Million in HH:MM:SS
TelstarRaspberry Pi 3 (1 Run)Raspbian5:12:57
EdisonRaspberry Pi 4 8GB (1 Run)Raspbian3:42:01
TeslaIntel i7-7th Gen DesktopWin 110:26:08
TeslaIntel i7-7th Gen DesktopUbuntu 200:18:21
Charlie DukeIntel i7-8th Gen LaptopWin 110:27:44
Charlie DukeIntel i7-8th Gen LaptopUbuntu 200:19:11
MarconiIntel i7-12th Gen DesktopWin 110:12:25
MarconiIntel i7-12th Gen DesktopUbuntu 200:08:57

One of the really cool pieces of data was the difference in the Marconi runs on Ubuntu 20 was 0.14 seconds from high to low.

The difference in the Windows vs Ubuntu really stood out this time. Here’s the 3 machines data individually:
Charlie Duke was 30.46% faster with Ubuntu
Tesla was 29.78% faster with Ubuntu
Marconi was 28.84% faster with Ubuntu

So, ultimately, I don’t know if this will mean anything to anyone but me, however I am enjoying this so far. Next steps:

  • Complete Household Data Gathering – Will run on Pi 1 and Pi 2, a 10th Gen Intel Laptop and a 2105 Mac Mini
  • Publish my complete data set.
  • Understand if I can port this calculation. Ultimately I’d love to try one of the old museum Cray machines to see if I can add those to the scoreboard.

If you have comments or thoughts for me on this, you can tweet me @N4BFR.

Telstar and Callsign Curiosity

Note: Initial post of this article was around 5 PM on April 20, 2022. I corrected the post around 6:20 to reflect the proper call sign.

In case you didn’t know, Telstar was the first satellite to do communications between 2 continents. It launched in June 1962 and lasted less than 9 months.

YouTube was nice enough to suggest this Periscope Film called “Behind the Scenes with Telstar.”

This left me with a few questions:

At 27:08 in the video the tech says “sending station identification” and you hear in Morse what appears to be DE KF2XBR.

Correction from initial post: I found a second video where you can hear the Morse Code and it’s clearer now. The call sign is KF2XCK as found in the linked video from AT&T Tech Channel.

I don’t know that satellites to this day that satellites have had their own callsigns, so I’m assuming this is the ground station call sign. That ground station was in Andover, Maine. (An additional Bell Labs Telstar video confirms at least the DE KF portion of the call.)

This raised a couple of questions for me. If it was a communications service, why didn’t it have a XXX#### type call that seems to have been given out at the time?

Why was if KF2*** when Maine is in the 1 call sign area? My guess is that KF2XBR would have been assigned to Bell Labs, and that would have been coordinated out of their New Jersey HQ. I looked at the 1961 and 1963 Call Books, but there are no K*2X* stations listed.

I’ll be doing more research but if I am to believe Wikipedia, all experimental call signs, not just amateur, were in this **#X** format.

I did find a later use of KF2XBR as part of a BellSouth permit granted by the FCC in 1990. These look like cellular telephone frequencies.

From reading through these FCC proceedings, it might say that these experimental calls were given out sequentially instead of by call region, because many of the calls listed were KF2X** calls.

An interesting fact I found when reading was that the US accidentally nuked the satellite after a high altitude nuclear test. Scientific American documented how the Starfish Prime test impacted Telstar, which launched a day later.

Upcycling to make the SpaceX Gate Sign

Back in January found an 80’s vintage airline gate sign in an antique store and decided to upcycle it into something that would fit in my tech center redesign.

Poor sign all unwanted.

I introduce the SpaceX Gate sign.

The sign was supposedly a Piedmont Airlines sign from Newark. It had no power or instructions but I knew I could get past that. Two power bricks later and the LED’s were working great. I reached out to the manufacturer but no luck on getting a manual. I powered along.

I reached out to AlphaGraphics in Dunwoody where one of my former co-workers had set up shop. They were great in going back and forth with me to get the sign elements just the way I wanted.

There are 4 possible “vehicle” inserts. Crew Dragon, Falcon 9, Falcon Heavy and Starship. There are 4 possible “gate” inserts, 39A at KSC, Pad 40 at CCSFS, Pad 4 at Vandenberg and Starbase, Texas. Here’s an example:

Prepared for the future!

I plan on updating this with the latest manned mission info, which is currently NASA Crew 4 as shown. The LED’s are updated with a slide out keyboard on the right.

You can see this in action and the entire build in a video on my N4BFR Vision You Tube page:

What do you think? Leave feedback on YouTube or tweet me @N4BFR.

Catching up on my YouTube Channel

I’ve been loading up YouTube lately with videos I have shot on the road. Here’s the latest:

I love this 4K time lapse with the natural sound of a sunrise in the park. There’s also a longer version for nature lovers.

I was lucky enough to be one of the operators for the W5B ham radio special event. Here’s what it looked like at the studio building.

I decided to spend some time fixing up a clock I got a great deal on. Here’s the first of 3 videos showing the fixup.

There are also a bunch of new shorts and some ham radio operating videos when you go to N4BFR Vision on YouTube.

Xiegu X108G HF Transceiver as a Shortwave Receiver

I purchased a Xiegu X108G HF Transceiver at the Dalton Hamfest from an estate seller. The radio appeared to be lightly used and in it’s original foam shipping container. I connected it to my LiPo battery and my dipole HF antenna to check reception. This video shows WWV on 10, 15 and 20 Mhz. All three frequencies were coming in to my location nicely on this Sunday morning.

My goal is to build this into a small kit with a battery and end fed antenna that I can keep in my car for when the POTA bug strikes me on road trips.

First impressions:

Sounded fairly good when warmed up. On first power up, I was picking up RFI bleeding in at 15 Mhz from a local broadcaster, whose transmitter is 6 miles away as the crown flies on 680 Mhz. That seemed to fade out as I switched around between the bands. I also toggled the preamp on and off, so I can’t isolate what the culprit is.

The best control of the radio seems to be from the Icom like microphone. I could switch bands, directly enter frequencies and try different modes like AM vs USB. I wasn’t impressed that USB was set to a 2.3 Mhz bandwidth by default, I prefer 2.7 so this was a little narrow.

The power on screen listed firmware from 2017 so I will be looking for options to upgrade that. It did not remember the frequency I was on when I turned it off and on, instead defaulting to 14.270 Mhz and LSB.

Dealing with an Instagram Clone

Saturday – February 12
I was enjoying a nice weekend on the beach when on Saturday Evening my cousin sent me this in Facebook Messenger:

That’s real me at the bottom and fake Insta-clone me at the top. She was nice enough to block and report the account that was asking for money. I figured, “hey, we reported this quickly, that should put this fire out quickly.” Ha! Just in case, I added a post of my own:

Monday, February 14
Home now and assuming that the now multiple reports of my clone have encouraged the Meta company to take action. Ha! The clone has not contacted me directly so I can’t find them to check on it. They did seem to pick my wife to hit up:

Now I have a name. Back into Facebook and Instagram to make some reports. I even reach out to the clone myself:

No response. The account remains. I add some background info to my followers.

Tuesday, February 15

It’s been almost 72 hours since the first appearance of the clone and the first report to Meta. The account remains on Instagram. I reported them again. I “escalate” to Twitter:

Wednesday, February 16

Escalation does not seem to have driven any action. I can confirm the suspect account has been reported a minimum of 5 times since Saturday. Another appeal on Twitter in addition to my daily reports,’

Thursday, February 17

It’s been 5 days since the fake Instagram clone account has appeared and I have not heard a single response from Meta, Facebook or Instagram. Today I try a new vector to disrupt this user. Since they are using a photograph I took on their profile, I have reported their profile for copyright infringement.

As of 12:05 this afternoon the copyright report is submitted:

and just to prove that I am reporting these daily via their tool:

Thursday, February 17 – 3:20 PM

Apparently Instagram cares WAY MORE about copyright infringement than stolen identities, because the picture I reported was removed in less than 3 hours. This is after FIVE DAYS of reporting the account. I hope this gives someone another tool in their tool kit to fight social media scum.

Let’s have a Happy Week

I’ve just had it with every ad on TV or streaming telling me how to vote, how the administration is handling the pandemic and just general tired of being down. So I’ve declared it “Happy Week” and I’m posting 2 songs a day to pick things up.





From the shop – 12V Power Pole Project

In my particular car, there is not a graceful way to wire the ham radio into a 12V battery so I have been using a 12V lighter socket. While it works fine, I am not happy with the fit and finish. The plug is in the way and it’s just not aesthetically pleasing to me. So I found a new plug and had to sacrifice the splitter part of the project to do it.

The Irwin Wire Strippers are available from Amazon: and so is the 12V splitter:

I receive commission from Amazon if you purchase those items through the links above. Also, if you like my projects and prefer to fund me directly, click the “tip jar” link at the top of the page.