[Help] some problems with lag

i host a muonline server 3 years and last year in the same dedicate i hosted 1.02N version with 2 subservers 500 ppl on(this was the record in both).But now in 1.00.18(season4 protocol) i cant get more than 20 without lag.

Dedicate Configuration:
CPU: AMD Opteron 8220 2.8,1mbx2 l2 cache
RAM: 12GB DDR2 800mhz each dual 3GB/channel
NET: my country 100/100 mbps peering except 1 network,extern 50/50mbps
HDD: 400GB SATA 2,32mb buff size

Last year RAM memory was 2GB,now with 10 more GB.What is the problem?The lag is like disconnect,delay at login,items from box drop delay(like 4 second).Sometimes stuck in arena/devias2(because of monsters),sometimes players are invisible in war map like arena,sometimes when players s/w their character stay online after s/w like 5-10 second and sometimes when exit(ESC->System->Exit) their character stay online until GM disconnect it or i disconnect it from JS.I dont see any problem in server configuration or internet speed,gs eat 1,56kb/s(and i upload with 4000kb/s-5500kb/s) with 20online and 9% processor and 1,6GB RAM up to 8GB RAM in 4-5 days because mssql 2008 eat more and more each day.Please HELP ME!

i think you better use MSSQL 2000 if that 2008 eats 8 gig ram lol xD

try to stop the servers from making logs as much as possible..
oh and the season 4 you are using is probably coded by the biggest noobs in the universe xD (this looks like a problem on a lot of season 4 servers... its just because of bad coding..) try to get other files.. cuz downgrading to your previous version probably isn't an option..

is not about mssql,with 2000 version the lag is bigger.And i have 3 versions of season4 coded by different teams and is the same problem with lag,i will format the HDD,maybe i got some virus or something