XMonitor for Mac

From Fork Networking:

XMonitor displays a wide variety of system information, shows you how much email you've got, checks the status of remote servers, and is highly customizable.

Monitors: disk, cpu, ram and network usage, PPP status, IP address, Email, Remote Servers and much more. Real-time, auto-scaling graphs of current activity, shows all mounted drive and disk free and used size statistics. Shows: system load, load average, number of users logged in, users logged in, number of running programs and active programs, %cpu used by the system, by user, and idle %, current speed, average speed, max speed, max send/receive speed per session, total sent/received since computer startup and receive/send split, free memory, used memory, wired memory, % of memory used, and total memory available. Disk current speed, average speed, total data read and written since computer startup, max combined speed per session. Total network and hard drive sent/recieved statistics since system startup and per session.

CPU information, bus speed, OS Statistics, uptime, MAC address, network interfaces, broadcast address, netmask. Adjustable: Transparency, CPU usage, Display mode, Graphing mode, Colors, text size and fonts. Horizontal, Vertical, and more Display modes. Utilizes a convenient, space saving layout. Able to automatically hide & show, snap to edge of screen, export History to html & jpeg images, export remote host status. Fixable scaling, POP3 and IMAP support, adjustable volume and customizeable notification sounds.

When purchasing XMonitor, you pay only what it's worth to you. Screen Shots. History Export example.