Optimisation Mods

This is not a new issue. We have been dealing with this for a long time. Pretty much since day one.

No there is no optimization mod for Rebellion. There really is no need for an optimization mod, because at maximum settings Rebellion doesn't use more than 1.7 gigs of ram (This is including the two DLC expansions). The dev's worked on reducing the texture footprints as much as possible, and fixed many glaring issues that were found during the creation of the Optimization Project for Trinity. Rebellion is about as "optimized" as it is gonna get. Short of re-writing the entire game. The textures are NOT the cause of the late game lag now. Its the CPU, or i should say lack of it.

The Iron Engine was designed for use in Single Core CPU machines running 32 bit windows XP. Vista was just being released when Sins was released. The reason for the late game lag is that Sins only uses a single core of your CPU. It does not matter what kind, How many cores, or how powerful your CPU is. Sins will use only ONE core. As long as your CPU is around the 2 ghz speed, or better range you should be ok for most of the game. Every one of us experience the late game lag.

Ill repeat what was said many times before. SD/IC WILL NOT update the game to use multi-core CPU's, or 64 bit. It will not be cost effective for them to do so. So the only things i can suggest if you are lagging that badly (before the usual late game lag) is play on lower graphic settings, smaller maps, with reduced fleet sizes, and stack your icons in the empire tree. Also turning off cargo ship icons seems to help too.

Fighters are a great cause of lag, there is a fighter reduction mod here somewhere. IIRC, it reduces the amount of strike craft and increases each damage.

Make sure that the person with the best upload rate is hosting.

Yeah, any mod you can find that reduces fighters, mines and/or tradeship numbers while also stacking the Empire tree and hiding trade ship icons is your best bet.

Starbase spam IMO does not help the late game lag issue either. The ability to build a Starbase at damn near every gravity well is kind of ridiculous. Especially when a fully upgraded advent starbase's poly count is well over 12,000 tri's. Sins can handle high poly units very well. However, if you include that starbase (as many as you can spam). Plus all the other factions units. Plus the particles. Plus "everything else on the map". A single core of your CPU, and 32 bit. Something is gonna give, and that is more than likely your framerate from cpu overload.

The thing is we tried poly reduction mods before, and found that they didnt improve the games performance very much.

The only thing that does seem to work is reducing the amount of units that are on the map at any given time (Like the strike craft, and trade ship reduction mods). It doesnt stop the late game lag completely, but it does allow you to play longer before it occurs.