My server's FPS is low

my server i7 4790k 32g 256 ssd 1g internet

today.. on first start my server fps is high 350~500 [20000entities]

but few hours later fps is average 10~50 .. and sometimes for a few seconds 100~200
[45000entities]

plugin used 127

i tested each plugin but i can't find the cause

player 20~35

what's the problem?
someone intentionally cause server lag?

 

127 plugins? Oh gosh :O
I think your i7 4790k should keep 1000-2000 fps with 20-50k entities.
Are you rent a VDS/VPS?
Of course, one of those plugins could be the issue too.

 

no. my computer
but only server work
[DOUBLEPOST=1520000713][/DOUBLEPOST]

I think building decay is causing the lag [ my server not use decay plugin . rust system]
or... very large building ..? but my server build 15x15 limit

 

I'm sure it's not a decay.

 

Can You Tell me Please what plugin are u using to limit building for Only 15x15 less or More ? Thank You