I am currently on my second playthrough of the game and experiencing absolutely zero lag.

What am I doing differently? I never fast travel.

My first play was all about getting to the end of the story, unlocking everything I could. My previous experiences with Bethesda games was that there are so many plot twists that I would sometimes not like the outcome. So I like to spoil myself and get all of that out of the way. I blew through the game using fast travel every time. By the end, my save file was about 14B and I would experience a lot of lag when entering a new cell.

Second playthrough, I have not used fast travel once yet. Not only do I find the game to be much more enjoyable (tons of beautiful scenery, tons of cool random encounters on the road), but I have seen zero lag ever and my save file is only about 6 MB. I did only buy one home this time, my favorite, instead of all of them.

Coincidence? Will this work for other people? I don't know. From reading other posts, the lag is caused by large file sizes, which is caused by having too much custom items and events in memory. I have also read that it takes a while for cells to reset and you have to be away from them for a while to get this reset. Perhaps constantly bouncing from city to city with fast travel never allows these cells to reset?

I hope this helps someone out there. I also found a way to zoom out in 3rd person. I don't think this was in the manual. When you are holding R3 down to switch to 3rd person, pull the left stick back. I find this birds eye view as I am jogging across skyrim to be very relaxing.

If you're on the ps3 it's probably because you save file is still small.

Yeah I agree. But I have played the same amount of content and have a smaller file size. What I was trying to throw out there for consideration and may have been lost in the commentary is....

If "Large File"= "Lag"

and

If "Cells Not Resetting" = "Large File"

and

If "Always Fast Traveling" = "Cells Not Resetting"

Then perhaps, "Always Fast Traveling" = "Lag"

Just something to think about.

Most cells don't reset for 30 days and 10 days respectively.

Though it depends what you mean by reset.

According to some of the forum speculation, the majority of the game's instability is likely due to memory overrun, most likely to due slow response in purging stale data from your computer's video memory... It would make perfect sense that CTDs tend to happen during times where you are buffering into a new zone (especially fast travel.

I was poking into my ini files one day, and if I recall correctly, there is a setting for the number of cells the game loads. As you travel in any direction in the game, it needs to load additional data for the cells you are travelling towards, while removing the data from the cells behind you. If I remember right from my poking around my game's ini files, my default loads 36 cells (a 6x6 grid). this would change based on your view settings. More cells=able to view longer distances. I will use 36 for an example...

If you are slow travelling through the game, and it is loading a 36-cell grid, then when you travel in any primary direction, each time you cross a cell-border, the game would need to load a new row/column of cells in front of you, and erase a row/column behind you, to preserve the appearance of a "seamless" world (IE: no loading screens. Dungeons/cities being the exception, of course). In my example rid, travelling in any primary direction (North, South, East, West), would require the game to load 6 new cells every time you traverse a border, and erase, or release, 6 cells behind you. Travelling in a secondary direction (Northeast, Southwest, etc.) and exiting diagonally from a cell could force the game to load both a row and column simultaneously, or at least, load a column and row of new cells in rapid succession, which would make the game load up to 12 new cells. However, If you were to fast travel from one end of the game to another, then you would potentially be leaving the entirety of your previous "grid" which would force the game to flush and reload ALL 36 new cells in one gulp. A much larger task, it is highly likely this would be where the crashes would happen...

One big difference though is that when you fast travel, you get a load screen, so the game dedicates all its resources to loading the new cells, doing it at its own pace, rather than also having to deal with physics and graphics and everything else as it has to when you're walking from cell to cell. Personally, nearly every crash I've had happened when I was traveling cross country, it's never happened when fast traveling. It did get considerably worse when I started to ride a horse modded for extra speed, I'd get several CTDs a day all when galloping across the countryside.