Extremely slow rendering of some PDF Files

[Marvin Hankley]

Binary package hint: kpdf

There seems to be a problem with KPDF which causes it to render some PDF files far more slowly than competing viewers, even ones which also use poppler, causing PDF reading to be unbearably slow on my OK system. I'll say that I've observed this problem with most PDFs. Here is one specific PDF which exhibits the problem:

http://www.archive.org/details/unpopularessays027477mbp

For the record, my system is an Athlon XP 2600+ with 512 Mb RAM. I have measured the average time taken to render page 100 of the above PDF in a variety of viewers, using an average of 3 measurements.

XPDF : 2.5 seconds
KPDF : 16 seconds
Evince : 5 seconds
epdfviewer : 8 seconds

As you can see, KPDF is the worst performing by far. The large delay when switching pages makes it impossible to use it on a daily basis.

Thanks a lot & happy holidays :-)

[TerryG (tgalati4)]

Thanks for your testing and bug submission.

Triaged to Confirmed. Tested with acroread 8 and it took 3 seconds. Since this is a 1950 book, the pages are scanned, so each page is actually a rasterized and compressed image. Not sure why kpdf would be slower, but it does make a good performance test case and I have added it to my collection of bad actors.

With KDE4 coming out, it would be interesting to test it against that build.

Acroread is not open source, but it is free, and it seems to handle books well.

[Marvin Hankley (marvin-hankley)]

Updated with KDE4 results:

XPDF : 2.0 seconds
KPDF (KDE3) : 12.5 seconds
Okular (KDE4) : 2.0 seconds
Evince : 1.5 seconds
epdfviewer : 3.0 seconds

It seems Okular from the KDE4 build is much better, it's just a shame that KPDF is currently so slow. Many thanks.

[Jonathan Thomas (echidnaman)]

This isn't an issue in Intrepid since Okular is replacing KPDF in both KDE and in Kubuntu Intrepid Ibex (8.10)