What is more efficient in setting up a server?

Question

Web development

Given:
Hardware:
3 servers in one data center
8 GB DDR3 RAM
2 x 750 GB SATA-II HDD (Software-RAID 1)
Intel® Core™ i7-920 Quad-Core (2 processors, 8 cores)
Software:
FreeBSD 8.1,
nginx 0.8.53,
php-fpm 5.3.3,
Mysql 5.1 (5.5),
Memcached,
apc,
postfix.
Sites:
High attendance, about 10 projects in total, three projects on each server. Projects on heavy Bitrix (most likely we will rewrite the entire engine and get rid of Bitrix). Each server is under heavy load.
Question:
In your opinion, will the configuration be more efficient, in which one server will act as a database server, and the other two for compiling php code (or one for compiling the second for static and caching).

Answer 1

What is high attendance? Bitrix has excellent caching of everything possible and wherever possible. On kraynyak there is even caching to statics.

Answer 2

No, "1 server under the database" in this case will not be so effective.
And, by the way, in relation to your hoster - be more careful there) they can give you 3 servers in 3 different DCs.
And according to the subject - first try to take 12 cores with 2xSAS and 1xSSD. On ssd - databases, on SAS - files. 90 hits per second is a lazy scratch for him. Well... if you even thought a little while setting up Bitrix, of course...
+ failover IP

Answer 3

It is useful to take out a database, but it must have a fast disk system or enough memory to cache the entire database.

Answer 4

and you can change the architecture so that a php script writes to the cache
and gives it directly from nginx
, the load is significantly reduced.

Answer 5

Maybe it’s worth starting with finding out what loads Bitrix so much, what does it do in general? And only then make decisions "how to continue to live."

Answer 6

Let's start with the fact that you have 1 processor in each server, and not 2, as you wrote.
There is no answer to your question in your formulation and cannot be. What will happen to the performance in your question depends only on the curvature of the settings. I would bet that the performance of the database will fall, tk. at its peak, it will be served not by 24 cores, but by 8. And whether the database is a weak point is not known.

Answer 7

I join the answer of inkvizitor68sl . At the expense of a heavy load, Bitrix has nothing to do with it, check the sites, analyze loaded pages with debugging enabled, see where your components are not cached or where there are many connections to the database, disable unused modules.