I've been struggling to resolve an issue with ctd's in the Riften area for a while now, and so far I've been unable to pin down what's causing it. I know the Rift is the most GPU-staggering area in the game what with flora and effects etc, but I'm not using anything which should add to that (apart from the DLC tex packs) and I even have the mod which lowers the res of the falling leaves.

I tried all the usual suspects re: mod checks, reinstallation, verifying caches, renewing ini's, even starting a new game; still the problem persists. What's more it is bizarrely predictable - freezing or ctd occurs as I am running towards Riften from the south, just as I pass Goldenacre Estate. (FYI I have no mods in the area).

Just wondering whether it could be a CPU bottleneck, or my system running out of VRam. My CPU is quite old (Phenom x4 2.3GHz) but will be replaced by an i7 soon! My GPU is a GTX 560 Ti with 1GB - so if the game's svcking all my VRam there's not much I can do about that except lower settings. Which I don't want to do and frankly shouldn't have to with the spec I have (or will have...) I also have 8GB RAM and a 64bit OS (Win 7).

I do use 2 player house mods; I know some users report issues with any mods adding cells but I did check the game with and without both (clean saves, ofc.)

Any thoughts?

CPU from the looks of it.....grab an i7 2600k
I don't use any of the player house mods which ones are you using?
Do you have SSAO enabled? My card doesn't support it and thus I have no clue how much GPU resources it would chew up.
I can get by with WATER, DLC Texture Pack, Crimson Tide and a few other smaller texture upgrades with Ugrids @ 9 with MSAA 4x using close to all of my VRAM(2 GB)

An i7 2600k is what I have on order...
I don't have SSAO enabled - given the difficulties I'm already having I wasn't sure I could risk it. Also not entirely sure how to go about it, tbh... The only texture enhancer I use is the DLC.

Player houses Autumn Lodge, which is in Ivarstead, and Mara's Eye Manor - though I just added it and haven't been able to get there yet!

Take a look at this mod, if you are only getting the issues around riften, perhaps reducing the leaves quality giving less rendering requirements there is a chance it may remove the added stress on your system in that area
http://skyrim.nexusmods.com/downloads/file.php?id=6387

Um... I did say I'd used that in the OP...! Doesn't seem to make any difference, unfortunately.

You most likely could have dropped a Phenom II X4 into your current motherboard (with a BIOS update at most) and gotten much better performance than your old Phenom 9600. Would have been about 1/3 the price of an i7, motherboard and compatible RAM. Your GTX 560 Ti is pretty choked down by that weak CPU. What's your motherboard make and model number?

Aint nothing wrong with Phenom II x4's

My fault, missed that

Yup - my Phenom II X4 @ 3.9 Ghz paired with a GTX 460 1GB runs the game butter smooth everywhere on Ultra (with only shadows on High).

And we saved ￡150+ by buying an AMD CPU and MB!!

(tbh I'm probably going to get an i5/i7 in a year or two, it's the next thing to future proof the rig)

Me too (and my system is three years old this summer), but for the time being I'm really not having to dial back settings too much in games to enjoy them. If you're getting a new system by all means go Intel - its the best choice today. But if you have a platform that can be upgraded, a drop in CPU upgrade makes sense and can get you another year or two's use out of it. The O.P. may have a prebuilt system thought and those can't usually have the CPU upgraded.

Current motherboard is ASUS M2N68 - really not sure I can bolt much on to that! Plus, as I say, it doesn't support PCIE 2 which further chokes said GPU.

The original post is about the game *crashing*, and whether or not that could be related to a lack of VRAM or a CPU bottleneck.

The answer is NO.

A slow CPU would result in stutters and a low frame rate, but not crashes (besides, a Phenom II X4 isn't "slow"). Running out of VRAM would not cause crashes either, since video cards can use your main system RAM to store textures - it's painfully slow, but it won't crash your game, and shouldn't happen with a 1GB video card unless you use an extremely high resolution and level of anti-aliasing.

The crash happens in a specific location in the game, so it's clearly related to the game itself. You should unload all mods, including those that lower the resolution of objects (no need for that with your system). Mods that affect one area can still cause crashes in a completely different area of the map.
Try uninstalling the game completely, removing all Skyrim-related files in your Windows profile folder and any program files left by the uninstaller, then re-install the game. Also, make sure you're running all the latest audio and video drivers. If all else fails, try a complete format and re-install of Windows (you'll be doing that anyway when you get a new CPU and mobo, which will most likely solve your problems).

I don't have a phenom II - I have an old phenom which has much lower specs, so it is slower!

And I already tried uninstalling the game and all related files, and mods. That clearly hasn't helped. I don't really want to reinstall my OS as that is a colossal pain in the proverbial, and I won't have to re-format when I rebuild with the new components (my partner is a professional in this field so it's not just me saying that!)

Besides, none of us should really have to go to such drastic measures. I have only got about 40 mods installed, 90% of which only make minor changes, like retextures. Might try removing the house mods though...

They were comparing the sandy bridge CPU's to the Phenom II quad cores like the 980 Black Denb etc...which are also really great. Just stay away from Bulldozer for now if you go the AMD route.

In regards to what Darkstarwe said that isn't true if the game was totally vanilla and was crashing I would agree but the crash is due to mods most likely in your case. It can't hurt though to do a total uninstall, reg clean and reinstall before buying new stuff. Still your CPU is weak and def could go for an upgrade as I can tell you already know.