Macbook 2013 vs 80 MHz WiFi channels

I found that the WiFi on my MacBook Pro (late-2013) works slowly on 5 GHz / 80 MHz channels (topping out at about 30 Mbps). Enough so that it's at least 3x faster when connected to the 2.4 GHz band in the same router (and I say at least because I can't measure any higher).

So, if your router works in the 2 bands and your Mac is switching between them transparently (as it usually does, which usually is advantageous), then you would be seeing big, mysterious changes in speed.


CrashPlan complaints

After a couple of months using CrashPlan I wrote about its awkward feature set and their interactions. The awkwardness didn't negate that it seemed to work well enough, better than the alternatives I tried at the moment. Still, it was also bad enough that it motivated me to keep my TimeMachine local backup, even though my earlier idea was to get rid of it.

8 months later, I'm fed up enough with CrashPlan to start looking for alternatives. This is a list of my problems with it, which are the things I would have liked to realize earlier.

All of these complaints have been brought up with their Support, even explicitly as feature requests and/or bug reports, and the eventual answers have not been particularly helpful nor encouraging; in the best cases Support just provided workarounds to suspend the pain for a while.


CrashPlan limitations

After a few weeks using CrashPlan PRO for small business (not the free tier!) I tried contacting support to ask how to do some underexplained things, and/or to open some bug reports/feature requests. Like:
  • How to know which were the last backed-up files? or, when was a file last backed up? (maybe some useless-but-frequently-updated file is slowing down backups of bigger and more important files?)
  • The app defines backup sets, but they don't seem to correspond to "restore sets". How to restore a particular set?
Support's answers were pretty underwhelming, bordering on canned-responses; but I found that Code42, the makers of CrashPlan, have an API to access the backup data. So I browsed a bit to see whether it'd be easy to do myself what I wanted.


Review of air purifier Prem-i-Air Invierno and air analyzer AirVisual Node

Living in Warsaw, I got tired of worrying about the air quality – which some days during winter got reported as worse than that of infamously polluted Beijing. So some months ago I bought an air purifier.

I had a number of doubts about how to use it so it was effective: does it have to work all day? The purifier's power level depends on the room's size, how do I know that it's working as it should? Air quality sensors included in these purifiers are said to be pretty unreliable, are they any useful at all? How does air quality indoors correlate to air quality reported by an official station about 1 km away from home – which daily recommended wearing a mask during winter!? What happens if I just leave the windows closed, or if I open them for a while? ...

So I bit the bullet and bought an air quality sensor, which cost almost as much as the purifier itself.
And these are my results and tips for anyone thinking about doing the same.


User-site-installed python packages, and PATH modification

Python makes it apparently easy to install packages. Just use pip, or any of the other more-or-less old and deprecated ways to install them, right? (heh)

The first difficulty is that maybe your system's Python needs sudo to install those packages, and you don't want (or even can't) use it.

The definitive solution is to use virtual environments, but that can feel like going too far in the "local" direction. You might just want to have something at the user level, without having the risks of using sudo, but still global for everything that the user does.

Well, turns out that PEP 370 allows you to have user-local installs of packages. You're supposed to run pip --user install whatever.

But now you have to remember to always use the --user flag! Kinda breaks the purpose of having something "global for everything that the user does".