Hello, according to your question, video storage does not stack.For example, suppose a GTX580 video card has 1.5GB of video memory. When two cards or three cards are exchanged, the video memory is still only 1.5GB and will not increase.In addition, the video memory bit width will not change.It should be noted that multiple factors need to be taken into consideration when engaging in a firefight. For example, whether the power consumption and cost of dual cards can afford to buy more high-end and better performance graphics cards. If you currently use the GTX580 or other graphics cards with insufficient performance, and do not need to consider the above issues, please ignore the above explanation.
It certainly won't overlap, just like two broadband bandwidth of 4 megabytes and the other wireless is also 4 megabytes, and the connection between wireless and broadband is still the network speed of 4 megabytes
