Re: All Graphics Cards related queries here.
Anti - Aliasing (AA):
Is a technique used to remove the distortion from images. All images are rendered by creating polygon shapes (primitives), and then joining them together. Now obviously a polygon does not have 'round' edges, so we will see jagged edges for non angular shapes. (Example a pipe or wheel). The graphic rendering system sees objects which will have edges of this manner, and apply an AA scheme to those portions of the image. These are basically again primitives which have a different level of opacity then the original image. These two are then joined at run time (the original smooth edges polygon+the AA supporting primitive) to create a non-jagged soft edge.
So if you set 4xAA as the render method it is actually rendering 4 primitives per pixel on your screen at run time...! It is extremely easy to correlate why the AA level immediately take a toll on the FPS.
A method(s) used by GPUs is Full Scene Anti Aliasing (FSAA) or Custom Filter Anti Aliasing (CFAA). You can say FSAA does the work in a full batch per frame. It takes the frame and renders it 2x or 4x times the normal resolution, and then down samples before it is pushed to the screen. So at 4x FSAA each pixel would have 16 super sample pixels. CFAA is a technology that ATI cards are using.
Anistropic Filtering (AF):
Is used to enhance the quality of 'textures' in images. It is used to show greater details at angles which are distant or oblique to the viewer. For example a farm house really far away. This is with respect to the camera and not actually the polygon. This takes up a huge amount of memory bandwidth. Lower resolution textures are used for objects that are further away from the camers (read player), to show the affect of distance.
To quicken this process a logic of 'mipmapping' is used. For example if a window is rendered using 256x256 pixels. Now you want to show this window at a distance, what does one do. It makes the window smaller in size --- but why use 256x256 pixels again..? So a shrunk version with a high quality filter is used. Any many such textures are 'stored' at run time, and re used over and over again. But this involves a lot of calculations and is resourceful on the GPU.
Now another issue arises. With so many mipmaps, when they are joined together, the 'joins' will not look nice. You will get uneven surfaces as distance is varied. We will see this as artifacts. This is corrected by using Trilinear filtering, in this method each mipmap is filtered along x-y axis but also with respect to the mipmap next to it. So as the angle is changed the AF will start to vary.
You have a good GPU. Try to run games, with these setting as a variable, you will start to see a difference. To notice AA, look closely at edges (no linear). And to notice AF look at distant objects. Yes these are important. They are the
eye-candy drivers, and vary the performance of the game.
Resolution:
1. 1400 * 900 = 1260000 pixels x FPS
2. 1024*768 = 786432 pixels x FPS
By using (1) you are getting ~ 40% more pixels on the screen. Of course you will see better images, but the GPU has to do more work, so you might see a performance hit.
And since you might ask about Tessellation too..here it is.
Here is a good link to an article. If you are from a programing background you would understand the new powerful features and capabilities which are available via the enhanced API. This will take make game programing to a higher level, and greater advanced features will be shown. Game programmers will quickly adopt to this new technology, and we as end users will see more game on this codepath.
I personally feel Tessellation will 'change the way' 3D will appear on our screens. Basically as of now 3D is rendered via polygons. Shapes are drawn inside wireframes, and pieced together using multiple polygons. And this wireframe is drawn over and over really quickly to shown movement. What Tessellation offers is that: these polygons can be further subdivided automatically into smaller and more detailed shapes, and each of these shapes can be 'controlled' for color, geometry. It gives power for greater detail and image enhancement, with far far greater control. All ATI cards which are >= 4xxx series have this tessellation engine in-built.
To see a classic example, go to
this link, and click on the wireframe buttons for the dragon and house. You will see the amount of polygon counts increasing by a massive amount to render the same image.
You could download the Unigine demo from the same link above, and run it. If you do not have Windows 7 and a GPU > HD4xxx, then run the demo in Dx9, and press F9 to see the wireframes. Its phenomenal.
And this is how a GPU functions:
The CPU is the central brain of the computer, and is managing everything. The CPU infact send the 3D data to the GPU. When it does this, it offloads a major task to the GPU.
The GPU is good at this, because the core is designed in a different manner. It is not a 'manager'. It is a HUGE calculation engine, which is extremelly data hungry ---> power hungery. Cause...
Basically a lot of mathematical calculations are done to convert from one format to another. This can be off loaded to the GPU core. The GPU core is efficient at doing this, cause it can calculate to really small decimal places. Light vertex numbers are done using this. So the GPU is really good at number calculations.
They have the architecture of 'stream processors'. This is the SIMD (single instruction multiple data) logic that the GPU uses. So multiple data points are applied a single instruction set in one go, very quickly. And these are all put in a pipeline -- which is the pixel pipeline. So imagine a pipe full of data which needs to have floating point calculations done on it. The data comes out of the pipe to the GPU and the calculation is done. Now there are multiple pipes like this which feed data to the GPU, which does the stream processing. GPUs are rated with the number of pixel pipelines available to the GPU.
This enables the GPU to quickly and efficiently process data. Perfect for 3D rendering or format transformation. It does all this, renders the 3D polygon image, and renders them on the screen.
Now correlate all of that, and you are good to go.....! Hope it helps...!