The Western Digital 40GB WD400BB 7200RPM PATA IDE 3.5" Desktop HDD Hard Drive is a reliable and high-performance storage solution for PCs. With a rotation speed of 7200 RPM and a storage capacity of 40GB, this internal desktop drive offers fast read speeds of up to 100 Mbps. Featuring a sleek black design and a compact 3.5-inch form factor, this Western Digital HDD is ideal for those looking to enhance their computer's storage capabilities. Additionally, this drive is compatible with IDE interfaces and offers a cache size of 2MB for efficient data processing.This 40GB 7.2K RPM 3.5" IDE / ATA (PATA) hard disk drive is a fast legacy storage option for older desktop PCs, workstations, and IDE-era servers that use a classic 40-pin IDE ribbon cable and 4-pin Molex power. Great for retro builds, replacements, and older systems that benefit from the higher 7,200 RPM spindle speed.