More info:

RB493G

The RB493G has nine Gigabit ethernet ports, three miniPCI slots, and two switch chips, so the ethernet ports can be connected together in two switch groups for wire speed throughput.

The RB493G also has a USB 2.0 port and a microSD card slot for adding more storage or a 3G USB modem for backup connectivity.

The heart of this device is a high performance Atheros AR7161 CPU and it features 256MB of built in RAM. RB493G includes RouterOS - the operating system, which will turn this powerful system into a highly sophisticated router, firewall or bandwidth manager.

Product specifications

Details
Product code	RB493G
CPU speed	680Mhz
Architecture	MIPS-BE
RAM	256MB
LAN ports	9
Gigabit	yes, all 9
MiniPCI	3
USB	1, external power required
Power Jack	10..28v
802.3af support	No
PoE	10..28V DC
Voltage Monitor	Yes
CPU temperature monitor	No
Dimensions	105mm x 160mm
Operating System	RouterOS
Temperature range	-30C +60C
RouterOS License	L5
Current Monitor	No

RB4xxG Series @680Mhz (Ethernet only test)			64 byte frames		512 byte frames		1518 byte frames
IP Firewall	Conntrack	Mode	Mbps	Fps	Mbps	Fps	Mbps	Fps
off	off	Bridging	76.9	150200	595.15	145300	1220.47	100500
on	off	Routing	52.38	102300	396.08	96700	1035.88	85300
on	off	Bridging	44.95	87800	353.08	86200	947.23	78000
on	on	Routing	39.68	77500	300.24	73300	823.36	67800
on	on	Bridging	29.9	58400	232.24	56700	660.63	54400

All throughput tests done with Xena Networks specialized test system and RouterOS v5, according RFC2544, with Ethernet frame sizes 64, 512, 1518 bytes.
Each board is tested with specified number of Ethernet interfaces, to ensure optimal load on hardware.
Values in Italics indicate that the maximum possible throughput was reached, limited only by ethernet ports themselves.
Test results show device maximum performance, and are reached using optimal hardware and software configuration, different configurations most likely will result in lower results.