Right, I have this issue and did post in the tech section about it the other week, but like a lot of posts, it got swallowed up. I have seen Cyron's previous posts on lagging but held off adding my own issue whilst I played my current game a bit more to see if the issue arose again.
1 - I have never used mods nor do I have cc. I have all EPS, SPS and most of the store (and all the worlds).
2 - I updated to latest patch a week before I got the game. No issues with my saves since the patch.
3 - Two days b4 getting ITF, I created a new Sim who went straight to university. When I installed ITF, she was still at Uni. I graduated her and sent her straight to the future without any game play issues. She lived mainly in the future but did go back and forth a few times to win the lottery.
4 - I got the Sim up to level 10 in Bot building and advanced technology. She was a self employed Bot builder. It was a few real days into playing the game that the issues started. The clock would jump by 2 sim minutes, then 5, then it would stick altogether. The game didn’t freeze but the Sim and the bots took ages to do anything. This started I think after my sim got her bot building statue.
5 - The lagging got so bad, I couldn’t play the game (clock ended up sticking for sim hours at a time). I managed to sell the bots and save my sim to the folder. I placed her into a new game – it made no difference.
6 - I have many saves for the many different worlds I own. They are all effected by this lag. Some more than others. One save is a family made up of a human, a genie, a genie child and an alien child. As soon as I went into this save (which was fine post patch but pre ITF) the lag issue was awful. It took sim hours before they did anything. The kids missed school – were hungry and wet themselves etc . I managed to take the human sim into the future by himself but there was still lag (10 sim mins +).
7 - After posting on the tech forum, I did a factory install. I even downloaded the store from scratch (over 2 days). It made no difference. The lag is in Sunset Valley as well as in store worlds.
8 - I have started a new game since ITF was installed. This Sim is a Bot builder and at level 10 Bot building (about 8 advanced tech). He has gone back and forth and as done the Dystopia and Utopia stuff (got the statue). I have had no problems. He got married to a present day Sim and they both live in the future full time. (she did have an issue staying in work but that is the only bug). No lags what so ever and I have played this game more than my first ITF save.
9 - As a side note – my only save they would not load is the only one where I have more than one generation ( 4 in this case – 2 of which are deceased).
10 - The clock stops at random times - not at a specific time. The sky gets dark/light etc and the world appears to carry on as normal. Sims stand there and do things such as twist their backs etc (as they would when bored or hanging around) but they don't move or react to actions for many sims hours. The clock just jumps from say 10am to 4pm.
I have windows 7 (64bit), Intel Core i7 CPU 860 @ 2.80GHZ, 8MB RAM, Nvidia GeForce GTX 260 video card.
I have never suffered lag (apart from the issues in Island Paradise) before and only seem to get it on saves prior to ITF being installed regardless of what world I am in.
Sorry for long post - very annoying not to be able to play old saves that I have spent time on.