On January 6, 2004 Apple introduced the Xserve G5, a redesigned higher-performance Xserve. The 32-bit PowerPC G4s were replaced with one or two 64-bit PowerPC 970 processors running at 2 GHz. Up to 16 GiB of PC-3200 ECC memory was supported on a 128-bit memory bus. One FireWire 400 port (front), two FireWire 800 ports (rear), two USB 2.0 ports (rear), an RS-232 management interface (rear), and two onboard gigabit Ethernet ports (rear) with TCP offload provided greater connectivity. A 133 MHz/64-bit and a 100 MHz/64-bit PCI-X slots rounded out its expansion options. Ventilation issues restricted it to three SATA hot-swap drive bays (80 GB or 250 GB each), with the original space for the fourth drive bay used for air vents. The front plate and slot-loading optical drive (CD-ROM, DVD-ROM/CD-RW optional) were retained from the last Xserve G4.