CertiGuide to A+ (Core Hardware)  9  Chapter 1000:  Multimedia       9  III  Video Cards

RAMDAC 1 Window RAM (WRAM)

As with all types of technology, the video memory for the frame buffer can come in many different flavors. Some of the more common types found on video cards today are:

• Video RAM (VRAM)
  
  
• Window RAM (WRAM)
  
  
• Synchronous Graphics RAM (SGRAM)
  
  
• Multi-bank DRAM (MDRAM)
  
  
• Video RAM (VRAM)

One critical limitation of using standard DRAM on a video card is its lack of available bandwidth.

The issue stems from the fact that the video co processor and the RAMDAC are competing for access to the video memory frame buffer.

VRAM addresses this issue by using a technology called dual porting.

Simply put, this means that there are two separate access channels to the memory, one for the video co processor and one for the RAMDAC. This allows both devices to access the memory simultaneously.

RAMDAC 1 Window RAM (WRAM)