There are so many tweaking suggestions for FSX, that it is difficult to know where to start. Or which tweaks might be useful, which ones are pure nonsense, and which ones might actually damage your FSX installation.
I won't claim to be a master tweaker when it comes to FSX, nor do I want to be. However, I have a learned a few things about Microsoft Flight Simulator over the years - and have recently had some very good luck turning my FSX installation from my "backup" simulator (behind FS9) to being my primary simulator. One that I use often, and now am starting to fully enjoy.
First here are a couple of articles that I wrote concerning video cards and FS9. I recommend checking them out. Especially if you are not really sure where your video cards stands in terms of capability.
Video Card Texture Loading Performance
Flight Simulator and Your Video Card
|KMSO - Missoula - Default Bell 206|
Letting your Video Card do more work on each cycle:
If you have a higher end video card, there is a very good chance that FSX is being to conservative in the amount of texture loading it allows to happen at any given time. What this could mean to you is that a chunk of "disruptive" texture loading work gets spread out across a longer period of time - which also spreads out the disruptions. Instead of simply doing the work that needs to get done more quickly.
If you have a higher end video card - and a computer that was new within the last 2-3 years. You probably can benefit from looking for the following line in the FSX.cfg file:
The default value is 40. Try changing it to 70, 80, or 90. Give each change a try. The most obvious effect will be that textures will load much more quickly when changing views between things such as the virtual cockpit and outside tower/spot views. If your hardware can handle it, changes in views will seem much more snappy. General disruptions in frame rate performance will also be decreased as textures will be loaded more quickly, and the disruptions will not be so spread out.
Here is an article to help with editing FSX.cfg if you do not already know how to do so:
FSX - How to edit your FSX.cfg
|Also...FSGenesis North America Mesh|
Some products that really make FSX look better.
I would consider the following add-ons must haves. Think of them as a foundation. As they are really aimed at improving the terrain fidelity and the ground texture appearance. There were must-haves for FS9 - and I think they continue that distinction for FSX.
Ground Environment X - Flight One Software
FSX Media Bundle - FS Genesis
|Also...Ground Environment X|
Blurry ground textures
The blurries in FSX are so commonly discussed acrossed the internet it can actually be difficult to find usueful information regarding them. In my case I knew I had adequate hardware, memory, and video card performance capabilities. Yet strangely, I continued to get partially loaded ground textures (ie. blurry) even fairly near my aircraft. I tried a few of the common "blurry texture" tweaks, but most of them revolved around tuning FSX down - to free up more resources for videocard memory. I have a fairly capable video card, and the rest of my hardware is pretty well matched in capability.
I ended up stumbling onto something very important in my case. I say "my case" because I can't be certain that it works the same on all hardware.
I set FSX to use "Anisotropic" filtering
BiLinear/TriLinear/Anisotropic filtering primarily has to do with how textures are rendered as they are viewed from oblique angles. This comes up a lot in flight simulation where you are perhaps looking down a runway before take off. Textures are easily rendered by video cards when they are at normal angles - like a wall in front of you. However, when viewed at an angle the hardware must jump through some mathematical hoops to try and keep them looking sharp and clear as the angle becomes greater. The filtering options are basically allowing you to choose the type of filtering work that will be used for this process. In general, the higher the filter, the more work the hardware has to do in order to render the texture. Better hardware can typically do this faster - and some older hardware can not handle filtering such as anisotropic filtering at all.
I normally use to use TriLinear filtering of textures. It provided the quality I wanted - while keeping performance where I wanted it. In FS9 I actually found Anisotropic filtering to produce a harsh - almost too sharp look to textures.
However, in FSX I noticed something strange
When I turned on Anisotropic filtering in the Graphics tab of the FSX display settings...The ground textures completely loaded. Every texture around my aircraft for miles was loaded correctly...sharp and at the proper resolution. Something about selecting Anisotropic filtering had definitely caused FSX to behave differently in how it was loading textures. This is not something you would assume from a texture filtering change. My guess is that the FSX developers tied that filtering option to some other behavior behind the scenes. I wanted to spread the word as best I can. I hope that this ends up helping you as much as it helped me.
A Heavy-duty tweaking thread
In addition to what I have discussed so far, there is a well recognized tweaking thread over at the Simforums website. I will link it here for you to check out. Most of the tweaks in this thread are reputable and actually DO have an affect on the simulator. I believe some are over-rated, but each person's hardware is different - so perhaps a teak there will really help you out.
SimForums.com - FSX Tweak Thread
My FSX Display Settings:
Most people have there own tastes for settings, but I will share mine for anyone that might find them useful.