Hello,

Seems that for some reason phpexpress has very poor performance on xen virtual machines.
Newrelic says that 4 seconds are spent in "CryptClass::decrypt", so it means server is decoding file.
I've tried both HVM and PV modes. hardware is super-cool - dell server, xeon cpu's, ssd drives.
If I run non encoded scripts - it runs fast.
If I run encoded scripts on virtualbox or vmware - it runs fast.
On xen vm there is a problem. It's extremly slow.
Does anyone know, may be some specific configuration required ? Some specific device must be passed to vm ?

you may want to check different locks and/or shared memory types. Probably, the default one(s) is not properly emulated by XEN.
First of all, open phpexpress() page, grab value in Configuration line, then add phpexpress.config with this value to your php.ini,
then try to replace 1st and 2nd arguments (they are shared memory type and lock type respectively). Supported values for memory are listed in Memory types and supported values for lock are listed in Semaphore types line.