I really hope someone can help, as this has been making me tear my hair out!
I host a forge server for my gf and I to play on. When I host 1.8 there is no lag at all! (30 mods) But we've been trying to play 1.7.10 as there is a larger mod pool to choose from. We have 32 mods so far on that server, but she starts to get really bad lag after playing for a few minutes. (Break blocks, but items lag to appear in inventory. Delayed damage, etc.)
A bit of info to help:
i5-4660 3.2GHz Quad Core
16GB RAM (4GB allocated to server in batch file)
GTX750TI-DF GFX card
We've tried making it unmodded, using hamachi, changing my DMZ, turning off firewalls/anti-virus/MWB. Nothing seems to help. Even a fresh, unmodded, "vanilla" 1.7.10 forge launch will make her lag after a few minutes. We've tried using various versions of the 1.7.10 Forge file. Have tried OPping, Whitelisting. Everything. I've searched multiple forums but have found nothing. She doesn't lag on our 1.8 server (hosting from same machine). She doesn't lag on non-forge 1.7.10 MC nor does she lag on other hosted servers you can find online that are 1.7.10: vanilla, forge, what-have-you. I cannot pinpoint the issue.
Just basic stuff. Hardmode, Survival, Online true, IP empty, port 25565. I didn't really change any of the configuration settings to keep it as similar to the 1.8 one as possible. Or are you asking something else?
Looks like there is an issue with your start up script 40963072 MB divided by 1024 = 40,003 Gig I think that needs adjusting also it looks like you have only configured your ram which could be why you are having issues.
You need to enter the arguments to tell java what kind of machine you are running and what it can use and also tweak this to the type of server you are running this can take some time and a fair bit of trial and error but it is the same as you adjust your client.
I renamed forge-1.7.10-10.13.4.1448-1.7.10 to server.jar so adjusted the batch to match.
I just find it weird that 1.8 would work fine with just the RAM adjustment, as would vanilla 1.7.10. I'm sure it's something to do with Forge itself, but I'll keep making adjustments until I get it. Any further help would be lovely.
Could you give me an example JVM for your machine? It would help a lot. <-- Upon further research I realized how pointless that would be. I'll keep learning in that case! Aside from that is there anything else that may be causing it?