Comments taken from bug 722903 / 721822:
(Frank)
>gnucash --nofile
6:2014/01/24 00-23-40:gwen(25640):gui.c:  125: Using own callbacks in gui
0x22e0e60
Found Finance::Quote version 1.18
>

but:

>gnucash
6:2014/01/23 21-24-48:gwen(6745):gui.c:  125: Using own callbacks in gui
0x1ceaf50
Found Finance::Quote version 1.18
java version "1.7.0_45"
OpenJDK Runtime Environment (IcedTea 2.4.3) (suse-24.9.1-x86_64)
OpenJDK 64-Bit Server VM (build 24.45-b08, mixed mode)
>

I think loading a java engine could have some impact.

(Geert)
I don't know why suse loads a java vm at gnucash startup. This is not the case
in Fedora and definitely not something added by gnucash. GnuCash doesn't use
java.

So the java issue should be investigated by the suse packagers

(Frank)
from http://lists.gnucash.org/logs/2014/01/2014-01-24.html#T11:13:41:
<DimStar> fell_: gnucash uses webkit.. and webkit is stupid: it loads all
plugins that are available...

So the first opened report starts webkit
and webkit loads the javaVM.

(Geert)
Frank, thanks for following up. I'm inclined however to ignore this part for a
couple of reasons:
1. GnuCash 2.4 did use webkit already as well. Certainly on Windows. So it
doesn't bring any additional slowdown between 2.4 and 2.6.
2. Loading the java vm is not something gnucash controls. That's something
internal to webkit.

If there is a way we can disable webkit plugins ourselves then obviously my
second reason is not correct. But then the requested change should be a
completely independent feature request outside of the scope of performance
comparisons between 2.4 and 2.6.