My programmer just built an application with PHP using Doctrine ORM (will be a high traffic social networking website), and it's very heavy in PHP/Apache and CPU. The queries are wonderfully fast, and MySQL is barely using any CPU, it's just Apache.
I was curious to if an SSD would help speed up PHP/Apache, because I know the bottleneck is in PHP reading multiple files, class files, and loading up a bunch of data.
So common sense makes me think if PHP is reading multiple PHP files, an SSD would only help as far as read/write?
I was thinking of doing a high performance SSD for the PHP application, but for user image uploads, I would just continue using a 15k SAS. Is there any performance issues regarding using an SSD in this kind of situation? And would it prove to help speed up PHP/Apache, and help the CPU problem out?
The only time you'll get an increase in performance is if your system profiling shows that you're currently bottlenecked on disk I/O. Does your system profiling show this?
I'd better profile your code to see where bottlenecks really are, as good SSDs are pretty costly and (at first glance) won't give you that much performance gain for that money.
What's load level you have now? Is it test system or production server with 1000's of users on it?
I disagree wholeheartedly with that last comment.
SSD will make a massive enormously huge difference in performance.
Unfortunately, most administrators out there are ignorant of what they need to do to properly setup SSD and the surrounding server system to make use of the SSD performance so all they do instead is use SSD as a drop in replacement for SATA and no that does not work to well.
It is something like buying a million dollar high end sports car and then using it to drive only to and from work each day because you don't know how to drive it to make use of it's potential.
Where I am at, we have properly tuned the systems across the board to make use of the SSD drives and the difference is far beyond amazing and well worth it.