A technical post for those who like to know a little more about what is under the hood.
In the 2011 release Revit added some graphics technology called OGS (One Graphics System). The name is derived from the use of the technology across multiple products in the company. This incorporation enabled the realistic view option where bitmap textures are shown in non-rendered views. I have been asked by a few customers if Revit will cache textures in graphics RAM just like a game system might? In this situation the amount of RAM on a video card becomes more important when making hardware buying decisions - especially if you spend a lot of time in realistic views. I am happy to say the answer is yes – Revit will fully use this RAM and the graphics team is continually looking to make improvements in memory management. This means textures will be processed on the board as long as memory on the card is available. When memory is not available the system will start to page and performance will deteriorate. Having the textures processed on the video card improves performance and the more materials with textures you use the more gain you will see. Also the more memory the more textures you can have before paging kicks in. I do not have hard performance data to share between cached on HW vs. not cached on HW but am rather confident that hardware with more memory will reduce any chance of paging and therefore aid performance. Note that textures stored in RAM are raw images so the size when loaded into RAM is often bigger than the images appear on disk. How much bigger? This is hard to say as it varies with the file format. The “lossier” the compression algorithm the bigger the difference will be between disk and memory. For example BMP images will have a small ratio while JPG might be big – especially if you lower the quality.