What is Refresh Rate?
The Refresh Rate is the number of frames (i.e., images) per seconds
displayed on a device Screen. The computer hardware support for graphics
consists mainly of a raster refresh buffer, or frame buffer, to store
the bit map. The image to be represented on screen is stored in the
frame buffer, and the bit pattern per pixel is read out to the graphics
display at the refresh rate. This is an independent part of frame rate,
that shows how many images are stored or generated per second by device
Display.
For producing higher refresh rate with less flicker, a cathode ray tube
(CRT) display is used which reduces the strain on human eye. CRT
contains a vertical scan rate is the number of times per second that the
electron beam returns to the upper left corner of the screen to begin
drawing a new frame. It is controlled by the vertical blanking signal
generated by the video controller, and is partially limited by the
monitor's maximum horizontal scan rate.
As in LCD the pixels which are displayed retain their state as long as
power as provided to them and constantly there is no intrinsic flicker
regardless of refresh rate.
How is Refresh Rate Calculated ?
It is particularly calculated from horizontal scan rate dividing by the
scanning frequency to the number of horizontal lines + time for beam to
return at top i.e., taken as 1.05x multiplier.
Ex.
Monitor with
Horizontal scanning Frequency = 96kHz(kilohertz)
Resolution = 1920 x 1080
96kHz~96000Hz
So,
96000 ÷ (1080 x 1.05)
= 85 Hz
The general specs available for it is 60Hz, 90Hz,120Hz, 144Hz. They manly measured in Hz(Hertz) because Hz is the unit for
measuring a frequency. In case of 144Hz will represent that the
frequency at which picture are displayed on screen are 144 images per
seconds or 144fps.
What is Resolution?
The Resolution is the number of pixels displayed on given screen. The
image is composed of a matrix of picture elements, or pixels, which can
be represented as a matrix of bits, called a bit map. Depending on the
size of the screen and the resolution, the display matrix in a typical
tablet ranges in size from 1024 × 768 to 2048 × 1536. A color display
might use 8 bits for each of the three colors (red, blue, and green),
for 24 bits per pixel, permitting millions of different colors to be
displayed. More the resolution of screen clearer will be the image. To
render complex 3D scenes an high screen resolution min.640px X 480px. at
interactive frame rate of 60fps.
