What type of RAM is used in the video cards of newer Macs due to its efficiency?

The type of RAM used in the video cards of newer Macs due to its efficiency is DDR-SDRAM (Double Data Rate Synchronous Dynamic Random Access Memory). This memory technology enables a higher data transfer rate compared to its predecessor, SDRAM, because it transfers data on both the rising and falling edges of the clock cycle. This effectively doubles the data rate, making it particularly advantageous for graphics processing, where large amounts of data must be accessed quickly and efficiently.

Moreover, DDR-SDRAM has a lower power consumption compared to older types of RAM, which is beneficial for laptops and portable devices where battery life is a concern. This efficiency in both speed and power usage is essential for maintaining optimal performance in graphics-intensive applications, such as video editing, 3D rendering, and gaming, which are common scenarios for Mac users.

The other types of RAM listed, such as SDRAM, SRAM, and DRAM, either do not offer the same level of performance and efficiency enhancements or are used in different contexts rather than for high-performance graphics processing in video cards.