Introduction
4 Software Developer’s Manual
1.3.5 Additional Performance Features
• Provides adaptive Inter Frame Spacing (IFS) capability, enabling collision reduction in half
duplex networks (82544GC/EI)
• Programmable host memory receive buffers (256 B to 16 KB)
• Programmable cache line size from 16 B to 128 B for efficient usage of PCI bandwidth
• Implements a total of 64 KB (40 KB for the 82547GI/EI) of configurable receive and transmit
data FIFOs. Default allocation is 48 KB for the receive data FIFO and 16 KB for the transmit
data FIFO
• Descriptor ring management hardware for transmit and receive. Optimized descriptor fetching
and write-back mechanisms for efficient system memory and PCI bandwidth usage
• Provides interrupt coalescing to reduce the number of interrupts generated by receive and
transmit operations (82544GC/EI)
• Supports reception and transmission of packets with length up to 16 KB
• New intelligent interrupt generation features to enhance driver performance (not applicable to
the 82544GC/EI):
— Packet interrupt coalescing timers (packet timers) and absolute-delay interrupt timers for
both transmit and receive operation
— Short packet detection interrupt for improved response time to TCP acknowledges
— Transmit Descriptor Ring “Low” signaling
— Interrupt throttling control to limit maximum interrupt rate and improve CPU utilization