DDR5 SDRAM (Double Data Rate 5 Synchronous Dynamic Random-Access Memory) is the latest and fastest type of RAM for desktop workstations as of 2023. DDR5 SDRAM offers higher speeds, lower power consumption, greater capacity, and improved reliability than previous generations of DDR SDRAM. DDR5 SDRAM can operate at frequencies up to 8400 MHz, compared to 3200 MHz for DDR4 SDRAM, which means it can transfer data faster and more efficiently. DDR5 SDRAM also supports dual-channel memory, which allows two memory modules to work together and double the bandwidth. DDR5 SDRAM is compatible with the latest Intel and AMD processors that support the DDR5 standard.

The other options are not as fast or suitable for a desktop workstation. DDR2 SDRAM, DDR3 SDRAM, and DDR4 SDRAM are older and slower types of RAM that have lower frequencies, higher voltages, and lower capacities than DDR5 SDRAM. DDR2 SDRAM, DDR3 SDRAM, and DDR4 SDRAM are not compatible with the latest processors that support DDR5 SDRAM, and require different motherboards and slots. DDR2 SDRAM, DDR3 SDRAM, and DDR4 SDRAM are more suitable for older or budget systems that do not require high performance or memory-intensive applications.