Wow this is indeed a lot faster.
2 sec render time now.
BUT there are 2 issues I could see:
1) The Decades Grafik doesnt work. It doesnt autoscale. If all values are over 100 then you get a chart where all columns are max.
2) More seriously, you use a hardcoded exec to /opt/bin/wget. Most php’s run with exec() disabled as it’s a security hazard. Can you maneuver around using an exec call and do it in php itself? One should defenitly not need to use wget in php, as php has plenty of functions to access images on the web and load em.
3) If google is for whatever reason down, then it simply wont show the grafics. Can you put in a fallback to the standard libchart method if googles api doesnt answer withing 10 secs?