为什么PHP脚本在新服务器上的执行时间长？

Question

I have a server that has 2 quad core processors (2.4 GHz, 16GB RAM). I have a some PHP scripts that run under very heavy load. Most of these scripts do few things:

1. Fetch Data from database (just a single row, from a small table)
2. Fetch Data from other server (mainly Facebook)
3. Upload a small photo
4. Update Database table (this table is very heavily used, and number of rows grows very quickly, almost 2 rows per second)

The problem is that, the scripts are taking too much time to execute. I had a server previously which has lower configuration (one quad core processor, 6GB RAM), but scripts took 4-5 sec to complete. But now, execution time is 30-40sec, even more.

HOW I MEASURE EXECUTION TIME? I measure microtime() at start of script and end of script and subtract them. I just needed a rough estimate.

SERVER CONFIGURATION: Here are some parameters set in apache config:

server_limit = 350
max_chlid = 350
keep_alive = off

Other Characteristics: 1. When server is not under heavy load, execution time is very small 2. Previous server took very less time to execute, even under heavy load

I don't know what else details should I include. Please ask me, and I will post them here.

What should I do to improve this?

Update:

I have figured out the problem is with ImageMagick library. I googled and tried few soution like disabling OpenMP. But it hasn't helped much

Answer 1

This could have many reasons:

1. Are your queries "slow"?
2. Is the server configuration right?
3. Has it a slow bandwidth?
4. Is MySql-Server configuration right?
5. What is the format of the table you insert?
6. Is something else (a cronjob e.g.) killing the database?

I would post this as a comment, but unfortunatly i can't please clear up those questions and tell what you find out ;)