What factors influence the FPS rate?

D

DelJo63

We are seeing lots of posts on issues of low or variable FPS rates being observed, so it begs the topic question.

Going to Microsoft's http://support.microsoft.com/kb/269068, we see these comments:
There are primarily three factors that affect the frame rate, and they are all interrelated:
  • CPU: A general rule of thumb for this is the higher the frame rate, the higher the CPU requirement. For the Windows Media Encoder to keep up with the data that is being sent to it from the capture card, a fast CPU is required. To keep synchronized with the audio stream, the Encoder will start dropping video frames to keep up with the data input. When frames are dropped the Current FPS statistic is lower than the Expected FPS statistic on the monitor panel. Note that some capture cards are only able to capture at 15 FPS, while others are able to capture at the full 30 FPS. Consult your card's manufacturer for specific details about your card.

  • Content Type: As stated previously, high-motion content requires more resources than low-motion video. Therefore, it is more important to properly select a CPU to handle the task, and to choose the right profile and key frame rate. If the encoding process cannot keep up with the content, it starts dropping frames. One exception to this is static content. If the content is a stationary object (such as a wall or an empty room), the frame rate may be lower because the Encoder does not need to capture any deltas.

  • Selected Profile: Each profile has frame size and frame rate determined. If you select a profile that the Encoder cannot keep up with, then select a lower quality profile. Multiple Bitrate profiles can also affect the Encoder performance. If the Encoder starts dropping frames, you may need to remove a stream from the profile, or adjust the frame size.
 
There have also been a lot of questions about refresh rates, which are very reliant on FPS. If anyone cares for a simple and easy to understand video on refresh rates, here is one.
 
The Youtube cited is good background in the physiology of sight, a prerequsite to dealing with our satisfaction with our gaming systems.

I'll be very specific re the term refresh rate. The term originates back into the early '50s with television which moved a CRT light beam across the screen in a diagonal manner. The horizontal movement was internally generated and vertical component was synchronized the the ac power - - 60hz. The refresh rate was "the number of times the screen was redrawn (upper left to lower right) in one second".

Our pc video adapters usually have user selectable refresh rates where 60hz is the default (wonder where that came from). Eye strain is reduced if you can set anything other than 60hz to avoid your video from being in-sync with the room lighting (especially fluorescent lighting).

Refresh rate pe se is fixed and not dependent upon the content. Frame rates alter just how much change is made within the refresh period. Gee whiz, if frame rate were to equal refresh rate, then every repaint of the monitor would have new information and our GPU would be very busy and likely be at its full rated outputs and power consumption.

The KB cited comments re choose the right profile - - good info but who and how to is unstated.
 
1. The amount of Shaders/CUDA cores
2. Memory Type (Dedicated, or Integrated) and Interface(64, 128, 256 and 384 bit),
3. Memory Speeds (clocks) and Generation (DDR3, GDDR3, GDDR5)
4. Amount of Memory (512 MB - 3 GB).
5. Your RAM amount and speed
6. Your HDD type (SSD vs HDD)
7. Background Applications and other Antivirus Scanners (AVs) and Scanners
8. Drivers
9. Power requirements
10. Dimensions
11. Manufacturer warranties
12. Cooling systems
13. Overclocking status
 
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