Forge modded minecraft server tps

[Dpat]

Hello guys, I have a major issue with our server we are running,

 

so we normally don't have tps issue but the last few days the server had been constantly running at 5-8tps, now to try and locate the issue we have disabled chunkloading and even set the server to peaceful, we have around 15 players in all the time and it has become unplayable.

 

i have the latest update of forge and the pack we are using is our own custom community pack.

 

any ideas what would be causing such a dramatic tps loss and if there is any plugins/mods we can add to try and help this issue.

 

i will add our server log file when I get home from work and also the specs of our dedi server. 

[Dpat]

Server Specs:

16x CPU - Intel Xeon X5675 @ 3.07GHz (8 running on one mc server and 7 on another 1 cpu on system)

MemTotal:       32936936 kB
MemFree:        16488172 kB
MemAvailable:   21540792 kB
 

and a 1tp ssd not sure on the spec of that,

 

so it is deffenetly not a hardwear issue,
only other thing i can think of is a particular mod causing this tps drop.

 

Mods we have installed 

Spoiler

Pictures below are all the mods we have