What is the main characteristic of the PCI-X expansion card?

The main characteristic of the PCI-X expansion card is that it uses a bus speed of 133 MHz. PCI-X (Peripheral Component Interconnect eXtended) is an enhancement of the original PCI standard, and it was developed to improve the data throughput capabilities of PCI. One of the key features is that it operates at a bus speed of 133 MHz, which significantly increases the available bandwidth compared to the traditional PCI bus speeds.

This higher bus speed allows PCI-X cards to handle more data simultaneously, making them well-suited for devices that require high-speed data transfers, such as network cards, RAID controllers, and storage devices. The architecture of PCI-X also supports backward compatibility with PCI cards, thereby providing versatility in the types of cards that can be used in the same system.

In contrast, other options refer to characteristics that do not accurately describe PCI-X. The reference to compatibility only with 32-bit systems is misleading; PCI-X is primarily a 64-bit bus architecture design. While there are some modes in which PCI-X can operate in 32-bit, its defining feature emphasizes its 64-bit capability. Additionally, the mention of a maximum bus speed of 64-bit is incorrect, as this reflects a misunderstanding of PCI signalling rather than bus