The AMD Ryzen 9 5900 is a desktop processor with 12 cores, launched in January 2021. It is part of the Ryzen 9 lineup, using the Zen 3 (Vermeer) architecture with Socket AM4. Thanks to AMD Simultaneous Multithreading (SMT) the core-count is effectively doubled, to 24 threads. Ryzen 9 5900 has 64 MB of L3 cache and operates at 3 GHz by default, but can boost up to 4.7 GHz, depending on the workload. AMD is building the Ryzen 9 5900 on a 7 nm production process using 8,300 million transistors. The silicon die of the chip is not fabricated at AMD, but at the foundry of TSMC. You may freely adjust the unlocked multiplier on Ryzen 9 5900, which simplifies overclocking greatly, as you can easily dial in any overclocking frequency.
With a TDP of 65 W, the Ryzen 9 5900 consumes typical power levels for a modern PC. AMD's processor supports DDR4 memory with a dual-channel interface. The highest officially supported memory speed is 3200 MT/s, but with overclocking (and the right memory modules) you can go even higher. ECC memory is supported, too, which is an important capability for mission-critical systems, to avoid data corruption. For communication with other components in the system, Ryzen 9 5900 uses a PCI-Express Gen 4 connection. This processor does not have integrated graphics, you will need a separate graphics card.
Hardware virtualization is available on the Ryzen 9 5900, which greatly improves virtual machine performance. Programs using Advanced Vector Extensions (AVX) will run on this processor, boosting performance for calculation-heavy applications. Besides AVX, AMD is including the newer AVX2 standard, too, but not AVX-512.