If you want it to boot quickly on this HDD, you better choose Void Linux than Ubuntu. Void Linux often boots 22 seconds faster on HDDs than Ubuntu. It's a bit less focused on user-friendliness, but if you want to learn, Void Linux is easier rather than difficult if you can read and understand a manual. I don't know which arch your hardware is exactly, but one of the following options should work:
voidlinux-ppc.org
Welcome to the Void
voidlinux.org
Are you planning to use the device for music/films/series?
In that case I would rather recommend helloSystem/GhostBSD/OpenBSD/FreeBSD instead of Linux.
The reason is that BSD has the best sound architecture of all operating systems, and Linux just the worst.
I can tell you my impressions with pulseaudio on Linux, I have used Linux for a long time on five different laptops/netbooks/desktops. A first impression I have is that the audio quality differs on Linux depending on which app and what type of connection you use (analog/HDMI/SPDIF etc.) I found the audio on Clear Linux terrible out-of- the-box on the analog (green) connection of my PC. With Ubuntu on other hardware I did an experiment with Quod Libet. You can easily get bitperfect sound through the settings of this audio player. I then compared this sound in bitperfect mode with FreeBSD's sound in bitperfect mode on the same hardware. And the sound sounded distorted on Ubuntu, quite noticeably distorted I mean. Other people could also hear this so it's not my imagination. On Arch Linux I found the audio better than on Ubuntu and Clear Linux, but not on the same level as FreeBSD either. I've used Arch Linux for a long time on several different types of hardware. In the end there is only one Linux setup where I managed to get decent sound out of Linux. This was a laptop with Fedora that I connected to the TV with HDMI, but I used an HDMI splitter that also had a SPDIF output to the 5.1 DTS Sony amp in combination with fancy Infinity speakers. Then in mpv media player I used the SPDIF passthrough option, and when I played movies that had DTS sound the sound was really impressive. But this is the only setup out of many different setups that accidentally delivered decent sound in Linux. So the overall picture is really not good, and I think windows usually has better audio than Linux.
It may be that Linux's audio is 'good enough' for you personally. But based on many other sources I can say it's not on par with FreeBSD's sound:
Why do people dislike PulseAudio?
Why is audio still so awful on linux?
So fast forward to 2007, when PulseAudio is actually unleashed upon the computers of everyone else except Lennart and his friends as it's adopted and enabled by default in Fedora 8. To put it mildly, nothing worked anymore. Very literally -- when we installed it at the crufty place where I held a part-time job there, it broke sound on every single one of the 10-15 different configurations we had, from laptops to desktops.
news.ycombinator.com
Why OSS sound quality is superior vs ALSA
OSS
linuxreviews.org
Open Sound System (OSS4) superior to ALSA
Open Sound System (OSS4) superior to ALSA
www.audiocircle.com