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GeoffR · 03-09-2013, 12:14 AM

I don't know about shelves, I only have 400 books on my Glo and haven't felt the need to create any shelves yet, but might when I get more books. From what davidfor has said on the subject it seems that less-than-optimal code/design is at least part of the problem.

But more generally the speed of things like displaying covers and opening books seems to depend a lot on whether the cover, book, etc. is already in memory. The first time I open a book it might take 3 seconds, but thereafter it only takes half a second, unless I power off the Glo or do something else that pushes the book out of memory in the meantime.

So I think anything that reduces the size of the objects the Glo has to manipulate will help. E.g. a smaller cover image will take up less memory and so be more likely to still be in memory the next time it is needed and less likely to push something else out of memory.

I noticed that kepubs downloaded from Kobo have black and white cover images, but when the Glo creates the cover image from the first page of a sideloaded book it stores it as a colour image, which takes more space. However if you send the cover image seperately using Calibre you can set it to send black and white images for sideloaded books too.

Another thing is that cover images are not saved for later use if the book is on the external micro SD card, and so will be much slower to display if they are not in memory. I imagine generating the cover will use more memory than loading a pre-generated one too, and so push more things out of memory and thus slow down other operations. You could get around this by replacing the internal card with a larger one and keep as many books as possible on the internal card rather than the external card.

Some books just seem to be badly organised. I have some where the cover and table of contents are at the end of the book that take a long time to open even in Calibre's book viewer, I think it would be possible to speed them up by reorganising the book but I haven't looked into this yet. But there does seem to be a connection between books that are badly formatted or structured and books that are slow to load or have other problems.

Overall I am very happy with the speed of my Glo, but any ideas to make it even faster are welcome, especially as more books are added (I hope to have a few thousand books one day :-)

03-09-2013, 12:14 AM	#3
GeoffR Wizard Posts: 3,821 Karma: 19162882 Join Date: Nov 2012 Location: Te Riu-a-Māui Device: Kobo Glo	I don't know about shelves, I only have 400 books on my Glo and haven't felt the need to create any shelves yet, but might when I get more books. From what davidfor has said on the subject it seems that less-than-optimal code/design is at least part of the problem. But more generally the speed of things like displaying covers and opening books seems to depend a lot on whether the cover, book, etc. is already in memory. The first time I open a book it might take 3 seconds, but thereafter it only takes half a second, unless I power off the Glo or do something else that pushes the book out of memory in the meantime. So I think anything that reduces the size of the objects the Glo has to manipulate will help. E.g. a smaller cover image will take up less memory and so be more likely to still be in memory the next time it is needed and less likely to push something else out of memory. I noticed that kepubs downloaded from Kobo have black and white cover images, but when the Glo creates the cover image from the first page of a sideloaded book it stores it as a colour image, which takes more space. However if you send the cover image seperately using Calibre you can set it to send black and white images for sideloaded books too. Another thing is that cover images are not saved for later use if the book is on the external micro SD card, and so will be much slower to display if they are not in memory. I imagine generating the cover will use more memory than loading a pre-generated one too, and so push more things out of memory and thus slow down other operations. You could get around this by replacing the internal card with a larger one and keep as many books as possible on the internal card rather than the external card. Some books just seem to be badly organised. I have some where the cover and table of contents are at the end of the book that take a long time to open even in Calibre's book viewer, I think it would be possible to speed them up by reorganising the book but I haven't looked into this yet. But there does seem to be a connection between books that are badly formatted or structured and books that are slow to load or have other problems. Overall I am very happy with the speed of my Glo, but any ideas to make it even faster are welcome, especially as more books are added (I hope to have a few thousand books one day :-)