I second this: "2nd hand Garmin Forerunner 55 and with a chest based HR monitor".
For heart rate training in general, the gold standard is an ECG-based chest strap. Avoid an optical-based monitor because you get some lag between readings or it even misses readings (this is especially evident during short intense intervals).
For a chest strap HR monitor, the main one is Polar H10, for a cheaper monitor you can get a Coospo H808S.
Saying that, I mainly use an Apple Watch Ultra 1 because it is convenient, it is good enough and I do not have to hassle with putting on a chest strap - I just have to settle with it taking a few seconds to register the correct heart rate after an intense set.
Honestly, just practice with a thing that does not cost a lot of money.
Once you desolder and resolder a full size keyboard multiple times (this is before hot-swap was available), most normal through hole PCB soldering jobs becomes easy.
300C on my TS100 for 63/37 lead (from a cheap brand) for any solder in the past 10 years. No extra flux, clamps or anything, just a wet sponge and an open window (or soldering outside), it sounds very basic but once you know how to solder you can do it anywhere.
For desoldering, a good solder pump will do. If a joint is hard to desolder, add solder and pump it again. You can use solder wick to clean up the hole, or you can just pump it again.
Sure, once you have an actual paying job with disposable income you can get all the nice tools, solder, and all that jazz, but it does not make you better, it just makes it easier.
Though saying that, a Hakko desoldering gun is well worth it - I am still good at using a pump and solder wick, but what a time saver the Hakko is.
I have bought some spare Kester leaded spools in case it gets banned for average the consumer, but nowadays I use lead-free SAC305 solder. It's safer clean-up, the only downside is that it does not look as cool. Also, definitely use an extractor fan for lead-free, the fumes are from lead-free are meant to be way more toxic than leaded - I get a headache from some whiffs compared to many more from leaded soldering (obviously try not to inhale any in the first place!).
I also confirm the $5 you get is only promotional credit.
I tested on my local LLM chat via Open WebUI, 2 requests from that cost $0.02 (so $4.98 left), and after my monthly Kagi renewal an hour ago, it did not reset, I am still on $4.98.
You are probably better off using Kagi Assistant anyways, as you get $10 there on the $10 Professional plan.
For local LLM web searches, to save on cost I will stick with the Brave Search API which gives you $5 free every month.
Well that's DDR4. Apparently DDR5 was made with tighter tolerances and less safety margin, which is why many people argue ECC should be mandatory in DDR5 - it actually relies on it.
There are plenty of DDR5 machines without ECC[1], and yet they're not constantly crashing in the way that frequent bitflips would suggest.
[1] DDR5's built-in ECC is not the same as traditional "end to end" ECC, and is meant to correct bitflips on the die, not between the RAM and the CPU, so ECC errors that you see are actually suggestive of a bad connection between the RAM and CPU.
For heart rate training in general, the gold standard is an ECG-based chest strap. Avoid an optical-based monitor because you get some lag between readings or it even misses readings (this is especially evident during short intense intervals).
For a chest strap HR monitor, the main one is Polar H10, for a cheaper monitor you can get a Coospo H808S.
Saying that, I mainly use an Apple Watch Ultra 1 because it is convenient, it is good enough and I do not have to hassle with putting on a chest strap - I just have to settle with it taking a few seconds to register the correct heart rate after an intense set.