ATC is a multiclan PvP campaign with 80 players played once a week.
During tests we have done, before the start of the campaign, our old server was showing great lag problems with very low server FPS and all strange of behaviours in game (scripts failing and so on) and it was really unplayable.
We tried different missions (both light non scripted missions and the well known Valhalla) just to understand if it had to do with the mission we were using and the server kept this lagging behaviour, so our attention was focused on the server performance. We discovered to have a lot of lost packets on our server connection, and the hosting company told us that they had recently setup a filter on UDP traffic to avoid hacker attacks.
We tried playing on another clan's server and found out that although the FPS were quite low, nobody had lags or any other problem.
So we decided to get a new server on this clan's hosting company and we bought a more costly and powerful option to try and be sure we would get good performance.
This is the new server specs:
Once our server was up we started testing again to find out we had the same lag problems. I investigated on the server and found out that it was only using one of the 8 cores (I mean really using, some threads were on the other cores but they were not working intensely) and infact, although we had very low server FPS around 1-3, the maximum CPU usage was only 15%.
So reading on some very interesting threads on this forum I found out that the server should have autodetected the number of cores, but that sometimes this fails so I put manually the Exthreads=7 and cpucount=4.
This showed a very different behaviour, now the server was actually using up to three cores and the overall cpu usage went up to around 30%.
So reading further I understood that since Hyperthraeding splits cpu's in two, in this case it would have been better to switch it off so that those 3 cores could have more power to them.
So now HT is off and the server can use during games up to 75% of the cpu power.
On our game this means that the FPS has greatly improved, infact during the same mission with almost the same number of players we have higher FPS which actually stays in the 30-40 zone....but suddenly it goes down to around zero, than after a second it comes back up to high values. This gives smooth game for about 30 secs and than a big lag to everybody: unplayable.
Further investigating showed that maybe those lags can be due to sudden big I/O operations so I thought of a disk bottleneck and started looking at the possibility of using a ramdisk and tried the Fancycache program, but we are still having these problems.
During the tests we have tried fiddling around with the server performance settings and we used the default values, the same values as our friend clan (which runs smooth but with low FPS) and also values from the Kelly's Heroes site who have a nice guide on these settings.
So now we are really lost, we are still paying both servers and any of your help would be greatly appreciated.