I read a lot about my problem. I have 4 years old Wordpress (with newest 3.8.1 Wordpress) site. And last months it become really slow. It takes about 3-5seconds to render page. In administration area is situtation more critical, there is 6-8seconds render time. MySQL queries are only 41 (when I disable all plugins) a it takes same time. But in frontend there is significant time reduction when I disable all plugins, but I want to use them. But there is almost no diffrence between 400+ queries (plugins on) and 60queries (plugins off). I use WP SUper Cache, which server pages really fast. But I want to debug my wordpress to see where exactly is the problem. I know that it might be a lot queries, but PHP works same time with 400queries and 60queries. So there must be some PHP bug, or something wrong.
I would like to have option to see what is taking so long to PHP, when it process all queries. Queries time is under 1second everytime with any amount of queries.
UPDATE: Ok, I got an idea. Because I am not a well skilled in MySQL or PHP I can share Debug Objects querry list. Is that good idea, to help me sort out this problem?