MT Cache performance between 2.9 and 2.7

hi guys

i noticed that the cache engine in 2.7 is better than 2.9 , do i have a problem of some kind? or its a common bug in 2.9?

Could you give more detailed information about your problem with cache in 2.9 ?
How did you compare, caching in 2.9 and previous versions ?

Yes, please elaborate. I would like to know what you are finding.