The numbers are for popular compilers. The actual sizes will vary according to the compiler and optimization used. Ethernet code sizes and RAM usage will vary depending upon the ethernet controller used, onboard or external.

8051 Processor
CMX-MicroNet v3.12k
Keil 8051 v8.17a tools, optimization level 9, size

Code Sizes (bytes)
UDP/IP (no TCP) + core	9444
TCP/IP (no UDP) + core	14,631
UDP/TCP/IP + core	16,243
(Please note that UDP/IP and TCP/IP are usually mutually exclusive)
IP Fragmentation	4463
TCP Delayed ACKs	1366
PPP	7679
Modem	799
HTTP server	6409
Virtual File System	1590
Ethernet	5485
DHCP client	3257
BOOTP	1312
FTP Server	5809
FTP Client	5916
TFTP Client	1264
SMTP	2899
SNTP	2917
POP3	5889
TELNET server	2814
DNS	1449
IGMP	1847
Utility	1975
SNMP v1 + v2 with default MIBs	4133
SNMP v1 + v2 trap	1355

RAM Sizes (bytes)
UDP/SLIP	161
HTTP	135
Ethernet	82
TCP Delayed ACKs	Number of resend buffers * (11 + transmit buffer size)

Without IP Fragmentation: add user selected buffer sizes + 63 bytes per socket

With IP Fragmentation: add user selected buffer sizes + 34 bytes + 83 bytes per socket + size of reassembly buffer(s)

Ethernet throughput numbers are calculated by timing the transmission of 60000 UDP packets containing 1470 bytes of data with Iperf.

Description	Speed (Mbit/second)
SiLabs PoE-VoIP-EB board with C8051F340 processor running at 48 MHz, CP2201 ethernet	2.32
SiLabs C8051Fx20-TB board with C8051F120 processor running at 49 MHz, CP2200 ethernet	2.31
SiLabs C8051Fx20-TB board with C8051F120 processor running at 49 MHz, CS8900a ethernet	2.20