User guide

NetXtreme II User Guide
September 2013
Broadcom Corporation
Page 170 Memory Usage Document INGSRVT78-CDUM100-R
DMA allocations at a minimum. After installation, it is suggested these descriptor counts be increased until stability is
guaranteed and the desired performance is reached.
For example, using the default setting of 2048 for the number of both RX and TX descriptors, the approximate amount of
memory a single interface would consume is:
Single Function Mode
• RX: 2048 DMA handles and 5M (MTU=1500) or 21M (MTU=9216) of memory
• TX: 20480 DMA handles and 5M (MTU=1500) or 21M (MTU=9216) of memory
• Total: 22528 DMA handles and 10M (MTU=1500) or 42M (MTU=9216) of memory
Multifunction Mode (#descs / 4)
• RX: 512 DMA handles and 1M (MTU=1500) or 5M (MTU=9216) of memory
• TX: 5120 DMA handles and 1M (MTU=1500) or 5M (MTU=9216) of memory
• Total: 5335 DMA handles and 2M (MTU=1500) or 10M (MTU=9216) of memory