Isn't it more of a CPU issue rather than a GPU issue?

TRIM YOUR EMPIRE TREE!!!!!

Same problem as me, that is why I ain't buying rebellion yet.

Select a "pinned" object (usually: capital ships, your own planets, your starbases) and press the icon that looks like a pin at the top left of the screen.

You can also hover over that icon to see which units in your empire tree are currently "pinned". Pressing the button pins or unpins the selected object(s).

Do the following:

1.  Use something that is TSOP friendly (by itself or inbuilt).

2.  Have very few graphic options on highest (I have just planets).  Medium is your friend.  Shit looks good upclose, but from afar, it doesn't matter.  Bloom will also be a big killer, as well.

3.  Strongly consider cutting the fleet supply in half and cutting the strikecraft per squadron down lower.  Trust me, the game plays just fine while doing that and it's just as fun.   Five hundred ship battles maybe cool in concept, but it's not worth it when you can't play the damn game.

I've also scaled all of my ships armor/health/fleet supply because of this.  Battles are longer and more dramatic.  Just not in the "OMFG, I HAZ BIGGER FLEETZ THAN YOU, YOU'D LOZEZ" mentality.

4.  Don't play on maps with any higher than 75 planets.

5.  Clean yo shit (aka the autopinning stuff).

If FPS is fine in the beginning and laggy later in the game, the problem is clearly with the amount of stuff the game is processing (ships, graphics, physics, etc) rather than with background services. Gamebooster helps by pausing background services.

I enjoy playing sins more on my weak laptop than my more powerful pc because both experience the late game lag and sins runs well enough if u follow the general rule:

Turn off virtual memory if u have more than 3gb of ram for all hard disks.

turn off indexing for all hard disks.

Set compatibility mode to run the game while disabling windows graphics features and lowering the resolution to 640x480.

Run the game at the lowest resolution 1024x768.

use only deep backgrounds or non at all. turn off the other stuff u don't need, (looks just fine with this background alone)

use low settings and the lowest engine trails etc

Biggest maps u should play are the first half of the medium maps.

Be aggressive with your gameplay and don't turtle. Attack, attack and attack on multiple fronts as well. Don't let the enemy accumulate a large fleet.

My Laptop Specs

Centrino 2: core duo 2 at 2.0ghz

3gb ddr2 ram shared with the gpu

Nvidia Geforce 9300 GS 256mb + shared

250gb hardisk. 20gb free space now.

Note:

make sure u don't overclock the CPU 2 much... the heat will also create a laggy experience. 2.4ghz is fine for medium maps.

Get 1 or 2 more gb of ram

i am running the most current version of sins.

as for the advice from reply #14, no offense, but if I have to do all that . .  no game is worth it.  I've got better things to do and better games to play than to sit here and do all of that crap.  I am the consumer. 

I turtle.  It's the way I play.  Unless the manual says "don't turtle  . . . .the game engine cannot handle it" then I should be fine.

I have high expectations.  Sorry.  And I have to pay $30 or $40 for Rebellion???  Dude.  Seriously.  With all of the games out there?  Come on. 

You know, the company that made Sins also made other games and I monitor how they maintain support for the other games (which I also bought). . . like Galactic Civ.  There are STILL issues with those games and yet their forums are dead.

Support.  Support.  Support. 

If I don't get it I move on.  I am the consumer. 

I work for a living too.  If I suck at my job, people will not buy from my store.  Simple as that.

p.s. my system specs:

win xp

2 gig ram

3.0 intel quad core  socket 775 Q6600

nvidia 8800GTX (OC'd to ultra)

Display 1280x1024

MOBO 780i

lol @knownalien . he wants solutions then shrugz them under the carpet when he gets them cos its too much for him . its like he has to dig a hole, pee in it , shit in it  and cover it all up with dirt to make it work than having the luxury to just quickly flush it down the toilet.

Here is your quick fix: click

Stop being lazy and google each tip people give you or youtube it for a visual guid.

Otherwise you can always go back in time to this: click

Well, without change on the sins exe, i can use around 3.5gb... exe with LAA crash when it is over 11.5gb... i can play with huge random multistar map, with 10 different races + pirates, all setting on very high, everything enable... 

The game and the iron engine is very strong and powerful... trick is that i don't use the game on any recommended OS but on Linux... update on Windows but play on Linux... well, not a solution for knownalien since he have better thing to do...

Well, it seem that "you know" wrong... the company who made soase is Ironclad and until now, it is their only game... Stardock is only the distributor/publisher... in fact, in my case, the distributor is Kalypso because i have the European version ( where localization was never updated )...

Well, again something about what knownalien is wrong... https://www.galciv.com/ ... the last post in the galciv forum is 5 days old... but the galciv II forum is very alive... maybe you can complain to Microsoft since the support for windows xp was ended in April 2009... people upgrade their OS... maybe it will be a good idea to move from galciv to galciv II... or maybe wait for galciv III ( http://draginol.joeuser.com/article/322138/The_future_of_Galactic_Civilizations )

i am really sorry that some here do not understand the gist of my post.  At the beginning of a game, it runs like glass.  smooth and perfect (at the highest settings & 4XAA).  but after a LONG game, it slows to 10-16 FPS. I build LOTS of SB's.

this is a coding problem.  This is not a problem with my computer UNLESS you can prove to me that more than 2 gigs of RAM (3 or 4) would drastically improve game play.  Specs for the game that are (rec'd) is 1 gig . . . . for your reference.

Sins in a long game will use almost 2 gig of ram and you only have 2 gig to run XP and all the background programs