Re: [RCU] Question about hw specs for roundcube

with 1500 concurrent users you mean 1500 different users connected to the web interface at the same instant? if so you will need more than a single web server and, perhaps, also a mysql cluster on different hosts than the web servers. (also don't forget to use imapproxy to avoid to start/stop imap connections every click of the user)

 Our server has 12 GB and ram & 1 quad core cpu (Intel i7 Nehalem), 

SAS RAID 1+0 BBWC. That should be enough to handle that load, we are asking for real-world experience about this.

 We are going to use jmeter to simulate load anyway, does anybody 

have real-world experience with this kind of load?

 Regards

 Javier