Flickering or 'tearing' is not a model problem but a sign of a system that cannot cope with the graphic loads, CPU first Graphic card second. What to do about this is not so comforting but not that hard. First I run a bog standard HP 4GB DDR3 Dual Core Processor with a standard Intel
Graphic Chipset of about 2 GB. The processor speed is nothing special at about 3.0 GHZ. The O/S system is WIN 7 64 bit.

Can I say I have learnt the hard way and I have done several complete rebuilds of FSX, every time I have learnt something new about FSX the program and how to work with it not against it, so just throwing memory and high speed graphic cards may work but not as well as most expect. I have also discovered over time that most flight simmers are obsessed with FPS rates which is basically irrelevant as far as the eye can see and FPS does not equate with CPU processing capacity.

My guess is that system you have will run CS stuff, mine does flawlessly and now and then with high loads ( I will come to that) it gets a little stuttery or lags but not badly or in a manner I cannot live with it, this always and I repeat always, occurs in scenery areas with complex and detailed scenery, such as any major city in the world. There are lots of things happening here with the graphics that relate to what you want it to show, what you have set the system to try and show and what the system is doing, eventually with MS FSX the whole shebang gets behind and you get tearing and out of memory problems.

A common problem with all simmers is that they allow various scenery addons to self install or rely on installation scripts etc to do this, with few exceptions this leads to a big mess in the scenery files in terms of layers and file orders this means that the FSX program is running all over the place trying to match the layers and programs runtime calls and driver demands. Lesson number one you need to get all of your scenery into a separate folder outside of FSX's main directory and you unfortunately have to learn how to add and layer scenery, once you master this and it will take a little while you will find the whole program runs very smoothly and you will find the FSX scenery library tools and management process works as intended. I will post links to very useful guides on how to do this.

Again you might consider a rebuild of FSX with no model or new aircraft added in but only FSX SP1 and SP2, again there are very good tutorials elsewhere on how to get this done properly. Before you do anything else, any changes to sliders or settings  you need to have a look at what FSX does with your system when it configures itself on intial install, it will set the optimal grahpics. FPS etc that it is programmed to do with the hardware and O/S version you have. That then becomes a starting point.

Third you need to get rid of any tweaks and forget about automation core. dll's get rid of them they don't really work and are covering up the fact that your basic FSX architecture and layering is mismatched with your hardware.

Once you have this basic data and set up you can begin to make fine adjustments to scenery, traffic etc and fine tune your system using the tools FSX provides via the user settings interface dialogue boxes, they actually do work and that is why they are provided.

Finally some tips, the big killer of graphic smoothness etc is AI traffic of any sort, level of scenery density and autogenerated scenery object density and clouds, the amount of processing time FSX is using to do the graphic changes is quite phenomenal.

Once you have this sorted out in the way you approach FSX then load in your Captain Sim model and begin to play with various adjustments to see what it does to your system performance and graphics. I think you will be surprised at the improvements.

So My Iron Rules:

No FSX cfg tweaks (there are two exceptions graphic file size only) and no automation core dll files.
No scenery addons into FSX keep them outside in separate directories and layer scenery correctly.
Keep all AI traffic down to a minimum of 16% or lower, you won't notice anyway.
Keep water resolutions low, you wont notice the difference.
Take out uneccessary enhancements such as shadows, cockpit tool tips, flare etc. You won't miss these either.
Ensure your DX settings for filtering are appropriate to your video driver and card.