Sunday, April 27, 2025

i7-7700K (2017) iMac problems

After selling my 2017 i5 iMac to a woman from Scottsburg and setting up my 2020 iMac, I needed to prepare my recently purchased 2017 iMac (with an i7-7700K) for resale.

The first step was to remove the Windows partition and erase everything on the computer — and that's where the problems began.

I used Boot Camp to remove the Windows partition I had previously created, which should have reclaimed the 1.6 TB I had allocated to Windows. While the program successfully deleted the partition, it reported an error when attempting to reclaim the storage space. I then tried using Disk Utility (the Mac partition tool), which also failed and told me to try running it from Recovery Mode, which didn't work.  A few years ago, I tried the same thing on my old, dying 2009 iMac, and that attempt had failed too.

Newer iMacs have a built-in feature to securely erase everything automatically, but while the option exists in macOS, it doesn't actually function on older models. So, the recommended method is to boot into Recovery Mode, reformat the drive, and reinstall the OS — a process I had successfully completed on the iMac I just sold.

Unfortunately, the 2017 iMac with the i7 processor reformatted the drive but threw an error during the OS installation. It simply refuses to install. At this point, I have a $400 paperweight with no operating system.

I'm starting to wonder if the 2 TB hard drive might be defective.  It is, after all, an eight-year-old computer.

Next, I'll try creating a bootable USB flash drive with the macOS installer using my 2020 iMac. According to everything I've read online, that's the recommended next step if the OS won't install through Recovery Mode.  It is probably what the repair shop would try.

Friday, April 25, 2025

My Lengthy iMac Story

My Lengthy iMac Story:

Because of rapid advancements, computers quickly become outdated. From 1995 to 2010, I bought a new computer roughly every five years. I remember telling my coworkers in 2001 that my new machine could boot up in just 2.5 minutes—they were impressed. But how could a computer I considered "fast" in 2001 feel like junk by 2005? And the cycle repeated itself in 2010.

However, during the 2010s, the pace of chip improvements slowed. Companies were touting only 5–10% performance gains each year. A big reason was that it became increasingly difficult to shrink chip circuits. Intel got stuck at 14 nanometers. It wasn't until 2020, when Apple introduced its M-series chips—starting at 6nm and shrinking to 4nm—that we saw a meaningful leap forward. Much of the credit goes to TSMC (Taiwan Semiconductor Manufacturing Company), which produces chips for Apple and many other companies.

My first Intel-compatible computer, which I bought in 1995, cost $1,200. It was a barebones 486 running at 33 MHz, lacking features that are standard today. Over time, I Frankensteined it—adding a sound card, optical drive, better processors—one component at a time. By the time I had spent $3,000 on it, it was so obsolete that it made more sense to just buy a new machine. Newer computers came with all the features pre-installed and cost much less.

In 2010, I bought an iMac because I wanted to do iPhone app development. It cost $2,000, already discounted from the original $2,400 price. If I had known it would take me so long to get into development, I probably wouldn't have bothered. I could have bought an equivalent PC for about a third less.

That 2010 iMac had a quad-core 2.8 GHz i7 processor with hyperthreading. At the time, it felt incredibly powerful—a huge upgrade from anything I'd used before. I told myself the higher cost was justified since it would last ten years.

About three years in, the power supply failed. One issue with iMacs—and all-in-one computers in general—is that they're harder to repair and more prone to overheating due to their compact design. By 2018, the power supply was failing again. A repair shop told me several components were on the verge of dying and that fixing it would be cost-prohibitive. By 2019, the machine was completely dead.

So, in 2019, I went shopping for another iMac. I found a used 2017 i5 model—twice as fast as my old one—for $1,050, which was a fair price at the time. I wanted an i7 version with hyperthreading, but those were going for $1,950 used.

By 2023, even this second iMac felt slow. The Android development tools I needed were nearly unusable due to performance issues. I realized I needed a faster computer—just a Windows machine for Android work. I could still use the iMac for iPhone development. So I bought a mini-PC with a 4nm AMD chip—five times faster than the iMac and capable of booting Windows 11 in just 7 seconds. Amazing.

However, mini-PCs can suffer the same heat issues as all-in-ones. They all use laptop components and compact cases. After 14 months of heavy use, mine overheated and died. It took three months to get repaired in China. Interestingly, the machine I got back was a bit faster. It was the same case, but I suspect some internals were swapped. The company wouldn't tell me what they fixed.

Then, in March 2025, a series of storms in Indiana triggered the next chapter in this saga. After several power flickers, my iMac died the next day. I brought it to a repair shop and, learning my lesson, bought a couple of surge protectors—which I highly recommend.

With my mini-PC still in China, I was stuck using an old laptop. Surprisingly, it streamed video just fine.

Worried that the iMac repair would be expensive, I started browsing for replacements. On Facebook Marketplace, I found a 2017 i7 iMac in Louisville—the same model that used to cost $1,950—for just $400. It was 60% faster than my i5. I was ready to buy it. But two things changed my mind: First, my i5 repair ended up costing just $50—a power supply cable replacement. Second, I admitted to the seller that I was nervous about the long trip to the south side of Louisville. I told him I didn't need two iMacs. He suggested I could sell my old one and even dropped his price by $50. That sealed the deal. I drove to Louisville on a day of severe flooding, had to turn around, and eventually found another route.

After buying the i7, I listed my i5 for $300. A buyer was interested, but I accidentally cracked the glass front while handling it. The shop quoted $500 for the repair. Although the crack is minor, the buyer backed out. I lowered the price to $200 and plan to keep reducing it until someone bites.

Meanwhile, Facebook kept showing me more iMac listings. Two 2020 i7 models appeared—one in Louisville, one in Carmel—both for $500. The Carmel one had more RAM and storage, making it more appealing. These newer models were twice as fast as my recent purchase and came with SSDs, which makes a big difference. I started wanting one of these instead.

The catch: the Carmel seller mentioned a scratch and a tiny crack on the right side of the screen. Since I was already dealing with a cracked-glass problem, I initially passed. The next day, the price dropped to $430, and then today to $380. I messaged the seller, drove to Carmel in more stormy weather, and saw that the damage was very minimal—so I bought it. A great deal.

Now, I'm trying to sell two iMacs.

P.S. Yesterday, my barber told me her old laptop takes 25 minutes to boot. I suggested adding more memory, but she didn't even know what that meant. I offered to take a look at it for her.

Tuesday, April 22, 2025

The WORST iMac to buy

My Super Weird 2020 iMac "Review"

I see that two people are selling this computer for $500 on Facebook Marketplace.   I am tempted to get one.

This is an 8-core machine with 16 threads (hyperthreaded).  This is comparable to my 8-core mini computer, but less powerful.  This machine is 7% slower than the 8-core M4 chip.

My point is that there are cheaper options than Apple Silicon.   It can run Windows.  It is upgradable.

https://www.youtube.com/watch?v=EMFCVvy0rkE

Saturday, April 12, 2025

The best mini PC I've tested! Minisforum UM790 Pro

https://www.youtube.com/watch?v=ca_5e5Yrv8M

@john2001plus
49 seconds ago
After 14 months of heavy use, my Minisforum UM790 Pro overheated and died. I saw sparks come from the side.

After arguing with the manufacturer in China, they told me I had to send it to the seller, also in China, for warranty service. Fortunately, the seller was willing to help me. Unfortunately, I used USPS to send the computer to China, and it took 41 days to get there. Three weeks later, the seller sent the fixed unit back to me, using DHL, which only took four days!

Three months after the computer died, I was up and running again!

Sorry America - WAN Show

I don't listen to three-hour live streams, but this one talks for 7 minutes about the disruption of the computer industry.

https://www.youtube.com/live/TWb2P-GGBcU?t=137s

In this 8-minute segment, he defends the United States.


Monday, April 7, 2025

iMac for Sale

For Sale: 27-inch iMac with 5K Display – Excellent Condition I recently upgraded to a newer model, so I’m selling my beloved iMac. It’s in excellent condition, both visually and functionally. Key Features: 5K Display: With over a billion colors and a bright 500 nits, this display is one of the best you'll find on any computer. The display and the computer itself are both sleek and free from any damage. Powerful Processor: Equipped with a 3.4 GHz Intel i5-7500 quad-core processor, this iMac delivers plenty of power for everyday tasks. It's three times more powerful than my laptop, which I use for streaming videos. 16 GB RAM: With 16 GB of 2400 MHz DDR4 RAM, this iMac offers more than enough memory for typical usage. For an additional $20, I can upgrade it to 24 GB RAM. BootCamp: This feature allows you to install and run Windows 10. Windows 10 activation keys are available online for as low as $4. AMD Radeon Pro 570 Graphics: Perfect for light gaming and 3D tasks, with a performance of 3.94 teraflops—comparable to the Sony Playstation 4 Pro. Condition: The iMac is in great shape, with no scratches or damage to the case or display. Note: I will reset the device to factory settings before handing it over to ensure it's fresh and ready for you.

Friday, April 4, 2025

My Computer Being Shipped Back From China

My mini-computer, which took 41 days to ship to China using USPS, was shipped back to me on Monday using DHL Express.  It has already reached Indianapolis.  

https://t.17track.net/zh-cn?spm=a2g0s.imconversation.0.0.54c13e5f4Bq0lP#nums=9502219484

Tuesday, April 1, 2025

Magnetic Core Memory

512 byes of RAM costing $2,000:

https://www.youtube.com/shorts/mrBz9-9qgGw

One of the biggest limiting factors of early computers was the cost of RAM.  In the late 1970s, I remember seeing an advertisement for 64K of RAM costing $1,000.  Today, you can get 64 gigs of DDR4 for under $100.

This is why the Atari 2600 video game system released in 1977 only had 128 bytes of RAM.  

The first TRS-80 came with 4K.  The VIC-20 had 5K.

The Sinclair ZX-81 came with 1K.  Its American counterpart came with 2K.  Both were expandable to 16K.

The Nintendo Entertainment System, first released in Japan in 1983, had 4.25K RAM.

By late 1983, RAM had gotten cheaper, so we saw the Commodore 64 released with 64K, and the Timex Sinclair 2068 with 48K RAM.

The REAL TechDweeb

This is most likley an April fools joke, but maybe the real joke is that it is true.

Computer Failures

My 2017 iMac just suddenly quit on me last night. I think that I got it mid-2019.

This is my second computer to fail recently. It can have similar issues as far as heat. I wasn't doing anything major on it. I was only streaming video.

One possibility is the power supply died. This happened to my 2009 iMac and I got it repaired for reasonable cost. Twice. Eventually the 2009 iMac had multiple failures and I had to get a different computer.

I tend to leave my main computer running all the time. I was in the habit of leaving my iMac on too, but I started using the sleep mode.

It is probably a mistake to leave the computers running all the time. Some people claim it is better to do that, because the spike in power can wear electronics, but I just had two computers fail.

This means my only working computer is my slow laptop I got used, hooked up to a 1440P monitor.

Good thing I have three computers.

I paid $1050 for the iMac, which was reasonable at the time. I've seen the same model for sale on Facebook Marketplace for about $400-$450. I have also seen discounted Mac Minis.

Took my iMac to the repair shop. I would have to factor repair cost with getting a replacement computer.

Monday, March 31, 2025

Update on Mini Comptuer



As I previously posted, my mini PC overheated and died in early January. After arguing with the manufacturer in China, they directed me to contact the seller—also based in China—for warranty service.

Fortunately, the seller agreed to honor the warranty, provided I sent the computer to them. I paid $83 for USPS shipping, and the package took 41 days to reach China. This was unusual, as I typically receive packages from China in three weeks or less. USPS tracking showed the package arriving in Chicago, departing, and then inexplicably returning to Chicago about a month later. At that point, I suspected there was an issue with shipping it to China and thought it was being returned to me. However, a few days later, it finally showed up in China.

After another week, the seller informed me that they would repair the computer. A week later, when I asked for an update, they said the repair would take one to two months.

Surprisingly, just a week after that, they said the computer was fixed and would be shipped back to me. I suspect that they had to replace the entire motherboard.

Assuming I receive it and it works properly, I want to prevent the overheating issue I experienced before when running the CPU at 100%. I originally bought this computer for its high performance, and the manufacturer had claimed that its cooling system could handle the heat.

One option is to lower the TDP from 55 watts to 45 watts, which the BIOS allows. This would reduce performance slightly but also decrease heat output. I could take a more extreme approach and reduce it further to 35 watts.

I should point out that some people on YouTube report boosting the TDP to 65 watts for better performance. A competing manufacturer does this by default with the same processor.

Apple is good at running its processors at about half the wattage. However, the M2 chip only gets half the performance.

Thursday, March 27, 2025

How smart is AI really?

For fun, I searched Google for "John Coffey USCF Rating"

Google's AI came back with this response:

John Coffey, a retired software engineer and chess expert, has an Expert standard Over-The-Board (OTB) rating and has given chess lessons for 37 years.
Here's a summary of what's known about John Coffey's chess background:

Occupation: Retired Software Engineer
Chess Expertise: Expert standard OTB rating
Chess Teaching: Has given lessons at chess clubs for 37 years
Online Presence: You can find his free lessons on http://www.entertainmentjourney.com



At first, I wondered how Google's AI knew so much about me, but then I realized that this response echoes my Profile on chess.com, which reads...

"Hello.  My name is John Coffey.  I am a retired Software Engineer.  I have an Expert standard OTB rating and have given lessons at chess clubs for 37 years.  You can find my free lessons on http://www.entertainmentjourney.com, along with other interesting stuff."

My initial impression of ChatGPT was that it was just a Wikipedia that could talk.  However, for about a month, I have been letting it touch my writing, and it does an amazing job. 


 


Saturday, March 22, 2025

The Path to AGI is Coming Into View


@john2001plus
0 seconds ago
It seems like the wrong approach. LLMs excel at language but are not well-suited for other tasks. The top chess programs, for example, are exponentially stronger than the best human players. A general-purpose AI would likely need to be a collection of specialized tools, each designed for a specific task. By developing enough of these tools, you could create a highly intelligent system.

Sunday, March 16, 2025

The OLDEST websites EVER

https://www.youtube.com/shorts/bdmmkwoketM

@john2001plus
0 seconds ago
Was there a website in 1986? I used the text-only Internet from around 1989 to 1995. I didn't download Netscape until around 1995, and the Internet was so sparse that I didn't know what to do with it.

BTW, I was a programmer on the Space Jam video game.

Wednesday, March 12, 2025

The Problem with Laptops and Heat - and the problem with Apple computers

https://www.youtube.com/watch?v=bq9O99TgFv4

@john2001plus
0 seconds ago
0:34 It is ironic that the video features the Minisforum UM790 Pro. Mine overheated and died after 14 months of heavy use. I argued with the manufacturer about the warranty, but they told me that the seller on AliExpress was responsible for warranty service. The seller agreed to inspect it if I shipped it to China. It took six weeks to arrive, and now the seller is examining the dead computer to determine whether they will provide warranty service. Mini computers use mobile components, making them similar to laptops. I now realize that a mini-computer is unlikely to have adequate cooling.

Wednesday, February 19, 2025

What does a yellow USB port mean?

xAI on X

elo score AI meaning

https://www.google.com/search?q=elo+score+AI+meaning&rlz=1C1ONGR_enUS1066US1066&oq=elo+score+AI+meaning&gs_lcrp=EgZjaHJvbWUyBggAEEUYOTIHCAEQIRigATIHCAIQIRigATIHCAMQIRigATIHCAQQIRigAdIBCDgzNjdqMGo3qAIAsAIA&sourceid=chrome&ie=UTF-8


An "Elo score" in the context of AI refers to a numerical rating used to measure the relative performance of an artificial intelligence model, typically based on a system borrowed from chess where models are compared head-to-head, with the winner gaining points and the loser losing points, allowing for a dynamic ranking based on their performance against other models; essentially, a higher Elo score indicates a better performing AI model compared to others in the same benchmark. 
Key points about Elo scores in AI:
  • Origin:
    The Elo rating system was originally developed by Arpad Elo to rank chess players, but has been adapted to evaluate AI models due to its ability to compare performance through pairwise comparisons. 
  • How it works:
    • Head-to-head competition: Two AI models are pitted against each other on the same task, and a human evaluator or automated system judges which model produced the better output. 
    • Rating adjustment: Based on the outcome, the winning model gains Elo points, while the losing model loses points. 
    • Relative ranking: This system creates a relative ranking, meaning a model's Elo score indicates how well it performs compared to other models in the benchmark. 
  • Applications:
    Elo scores are commonly used to compare the performance of large language models (LLMs) where different models can be evaluated against each other on tasks like text generation, question answering, or translation. 

Thursday, January 30, 2025

Duck Duck Trump

Explain Quantum Physics in the style of Donald Trump
ChatGPT said:

Look, folks, quantum physics—it's tremendous, really tremendous. People say it's complicated, but let me tell you, I understand it better than anybody. You've got these tiny little particles—very small, some say the best particles—that don't behave like normal things. They can be in two places at once! Can you believe it? Some people call it "superposition." I call it winning—being in two places at once, very efficient.

And then you have "entanglement"—it's incredible. Two particles, miles apart, maybe billions of miles apart, but they're connected. Some people say it's like magic, but it's just very, very smart physics. Scientists are amazed, they can't explain it, but I could explain it, believe me. They call it "spooky action at a distance." Spooky! But let me tell you, it's not spooky if you're the best at it.

Now, quantum mechanics, it's got waves, probabilities, all sorts of things moving around—very unpredictable, just like the fake news media. One moment a particle is here, the next, it's over there, just like votes in certain elections—very suspicious. But it's science, and we love science when it's done right, don't we?

And quantum computers? Very powerful, folks. Some say they will change everything, just like I did. They can do calculations so fast, so big, regular computers look like sleepy Joe next to them. Very slow. Very sad.

So, in conclusion, quantum physics—it's big league, it's amazing, it's the future. Some say it's the best physics, and I tend to agree. Tremendous!


Re: Duck Duck Trump

Write a joke about a duck in the style of Mike Tyson
ChatGPT said:

Alright, here's a Mike Tyson-style duck joke:

"Man, so I see this duck walking down the street, right? And I'm like, 'Yo, you lookin' kinda lost, little fella!' And the duck goes, 'Nah, I'm just trying to find a good spot to swim.' I'm like, 'Bro, you don't gotta find nothin'. The best place is right here. Just dive in and keep your head straight, 'cause you never know when someone's gonna throw a punch... or a breadcrumb!"


Duck Duck Trump

Write a joke about a duck in the style of Donald Trump
ChatGPT said:

Sure! Here's a Trump-style joke about a duck:

"Listen, I know ducks. They're great, okay? The best ducks, people are saying it. So this duck, he walks into a pond—very classy pond, folks. It's huge, it's beautiful, the best pond you've ever seen. And the duck looks around and says, 'This is nice, but I hear there's a much bigger, much better pond down the street.' And I tell him, 'That's fake news, okay? This pond is the greatest, and I built it. Believe me!'"

Tuesday, January 28, 2025

Comparison of mini desktop processors

https://www.cpubenchmark.net/compare/5157vs2910vs4922vs5454/Intel-N100-vs-Intel-i5-7500-vs-Apple-M2-8-Core-3500-MHz-vs-AMD-Ryzen-9-7940HS

The N100 is widely used in many affordable mini-PCs, some costing as little as $100, making it a great value. However, a couple of Christmases ago, I gave my stepdad an outdated desktop computer that I bought for only $30—and it's almost as powerful.

My 2017 iMac with the i5-7500 chip isn't much better. I was dissatisfied with its speed and wanted something significantly more powerful.

Apple has focused on promoting mini and mobile computers, as well as tablets, with their M-chip series.

In early 2023, AMD claimed its Ryzen 7940HS was an "M-chip killer." Technically, it's also a mobile chip, similar to Apple's M-series, and it first appeared in some very expensive laptops.

I decided to buy this chip because it's an APU, like the ones used in modern game consoles, with the graphics card integrated into the main processor.

In August 2023, I purchased the Minisforum UM790 Pro. Unfortunately, it overheated and shorted out recently. The manufacturer informed me that I need to go through the seller for warranty service, and the seller—who is also based in China—has offered to inspect it. I'm shipping the unit to China today.

Minisform is now making a newer model, ironically with a larger case and better cooling, so the computer I bought is being discounted and possibly closed out...

https://store.minisforum.com/products/minisforum-um790-pro?gad_source=1&gclid=CjwKCAiAneK8BhAVEiwAoy2HYbymkT9LkczEaXsVe74yhU1M_2lN2UQBdOm3Uw279nwFNOlrKNF8BRoCsOMQAvD_BwE




FreeFileSync: Open Source File Synchronization & Backup Software

This is useful.  I use this program to sync all my backup files on my two computers and a laptop to a 5 TB hard drive.   When my main computer recently died, I still had all my files on my 2017 iMac.

https://freefilesync.org/

Wednesday, January 22, 2025

Don't Make These 3 Mistakes in C! Can YOU spot the bug?

I find this interesting.  My C programming experience goes back to 1986, so I am probably unaware of any new changes to the language.

C is my preferred language, followed by C++, although I was adept at many assembly languages as a video game programmer.

https://www.youtube.com/watch?v=LLykqRNuEwA

Wednesday, January 8, 2025

Fwd: Failure of Minisforum UM790 Pro

Mini computers have been really popular and many people think that traditional desktop PCs are on the way out.  Instead, people will buy mini computers, laptops and tablets.

This is mostly because of Apple, which has released some very powerful small devices.  Mini computers often use laptop parts, and the 'M' in Apple's M-chip series stands for "Mobile".  Apple uses the same powerful processors in laptops and tablets.

AMD claimed that their Ryzen 9 7940hs is an M-chip killer.  I knew that I wanted something like this, and I waited four years to get the right chip.   It has twice the processing power of the M2 chip, and unlike Apple, the computer I bought has upgradeable storage and memory which they don't charge you a fortune for.

However, mine failed after 15 months.  I'm not sure if it is fixable.  The motherboard is custom to this computer, and might not be replaceable.  However, I could buy the cheaper "barebones" model that lacks memory and storage, and transfer those from the broken computer.

The processor uses up to 55 watts under a full load, which is almost as much as a 60-watt lightbulb.  I could feel the heat coming off of the computer, and I was concerned about this.  Maybe a regular desktop would be easier to cool.  (By the way, a competing mini-computer company overclocks the same processor and it uses 65 watts.)

Apple often uses less power to keep their computers cooler.

Minisforum is a Chinese company apparently in Hong Kong.  Some might claim that this is typical Chinese-made quality, although everything is made in China.

I sent a complaint to Minisforum...


---------- Forwarded message ---------
From: John Coffey <john2001plus@gmail.com>
Date: Wed, Jan 8, 2025 at 2:09 PM
Subject: Failure of Minisforum UM790 Pro
To: <support@minisforum.com>


Failure of Minisforum UM790 Pro.

I purchased a Minisforum UM790 Pro from Ali Express on August 22, 2023. It arrived in about five weeks. Because of circumstances in my life, I was not able to use it until late October 2023.  The computer lasted less than 15 months.

I bought this computer because I wanted a powerful computer for chess analysis. It is five times faster than my other computer, and I often ran it at 100%.  

I was a little concerned about the heat the computer produced.  I could feel a steady stream of hot air coming from it.   I thought that it would be okay because you have advertised it as having  "Cold Wave 2.0".  I assumed that the computer was capable of running at 100% for long periods.

This morning I was doing some intense chess analysis on the computer and it suddenly quit.  I tried to power it back on, but it would not turn on.  I disconnected and reconnected the power and it would not turn on.  Five minutes after the initial failure I saw orange sparks like a tiny fire come from the left side.  I could smell smoke.  I disconnected the power.

To use an English expression, I assume that the computer is "fried."  Other than doing intense chess analysis, I have not abused the computer in any way.

I am not sure if I can get this repaired.  I don't know if the motherboard is replaceable or repairable.

I was hoping that you could advise me.

I am disappointed in the quality of the computer that it would fail this way.  However, I am considering getting the less expensive barebones model and trying to transfer the memory and storage to the new computer.  

--