Improving InkBox performance

Could replacing the SD card improve performance?

TLDR: maybe

Long answer:

Some benchmarks of some SD cards

Very random green sandisk SD card:

Original kobo nia C SD card:

Goodram SD card, pretty new one:

Old tolino shine (so kobo glo) SD card:

So yes, ~7 year old SD card is slower than newer ones. Could replacing it improve performance? It depends on the CPU limit for it, quality of PCB traces, even linux kernel version. So maybe.

My device is slow, in htop I see squashfuse processes

I saw this on a kobo glo, not once on a kobo nia, so it's SOC dependent. if you want to fix it, consider creating the squashfuses with no compression at all ( this will decrease your available space... )

My device boot is slow / everything is slow

consider disabling xorg, it takes some ram in the background at all times

Xorg apps are slow

Don't expect anything from xorg apps, it's a miracle they work at all. If you want to fight with it, consider removing compression from squashfuses, it could help with loading time