When I attempt to graph a keyword with the new 8.x feature, I get:
Fatal error: Allowed memory size of 134217728 bytes exhausted at /usr/ports/lang/php5/work/php-5.3.8/ext/standard/var_unserializer.c:288 (tried to allocate 71 bytes) in /usr/local/www/piwik/core/DataTable.php on line 1057
I did not get this error with 8.0. Also my memory limit in php is set to 2000M. To be sure I checked php.ini and it does read 2000M. I also did a restart on apache just to be sure.
I suspect this issue is with the new piwik version.