Yes, it can slow down. Maybe memory leaks or something and a reset fixes it. However it's still deadly slow.
My Kindle DGX has been slow and pathetic for PDFs since new. The PW3 is better (300 dpi vs 150 dpi), though the text might very small.
The Kindle UI messes up if the Kindle time & date isn't set. On the DXG that can only be set either by 3G/Edge connection (gone some places), or a jailbreak (all can be jailbreaked, so most recent FW is a good idea, 2.5.8?), then USB networking.
If you think the PDFs are fast, you must only have a DXG. Save up for a real ereader or Nxtpaper 14.
|