Video RAM (VRAM)

Video Ram is a dual-port memory with one random access port and one serial port access .


The standard DRAM used for video cards usually does not have bandwidth to handle the demands of running a card at high resolution & color depths, with acceptable refresh rates. The main reason why is the competing access factors for the video memory: the processor writing new knowledge to the memory, & the RAMDAC reading it lots of times per second in order to send video signals to the monitor.


To address this essential limitation, a new type of memory was created called video RAM or VRAM. As the name implies, this memory is specifically tailored for use in video systems. The essential difference between VRAM & standard DRAM is that VRAM is dual-ported. This means that it's access paths, & can be written to & read from simultaneously. The advantages of this are of coursework sizable given what the video card does: lots of times per second a new screen picture is calculated & written to the memory, & lots of times per second this memory is read & sent to the monitor. Dual-porting allows these operations to occur without bumping in to each other.
VRAM provides substantially more bandwidth than either standard DRAM or EDO DRAM; double in lots of cases. It is more suited for use in systems requiring high resolution & color depth displays. The only reason that it has not replaced standard DRAM entirely is of coursework: cost. VRAM is more complex & requires more silicon per bit than standard DRAM, which makes it cost more.


Note: Don't confuse VRAM with the generic term "video RAM" or "video memory", which refer to the memory in the video subsystem in general.