2. The M1 Killer NIC Incorporates Lots of Special Features

The heart and brains of the Killer NIC is a standalone CPU, which Bigfoot naturally calls an NPU (short for network processing unit). In the M1 model, it’s a 400-MHz PowerPC processor that runs a standard Open Source version of Linux based on the 2.6 kernel. It also includes its own network controller that works with GbE (1000 Mbps), Fast Ethernet (100 Mbps) and 10BaseT (10 Mbps) media, all through the same RJ-45 connector. To provide room for the OS to work and to accommodate ample buffer space for the TCP/IP stack, the card also includes 64 MB of hard-soldered PC-2100 DDR RAM (266 MHz). To avoid involving the CPU overmuch in data transfers to and from main system RAM, the Killer NIC also functions as a bus-master direct memory access (DMA) device, which means it can coordinate its own memory transfers directly, without requiring the CPU’s intervention or assistance.

To facilitate use of some of this card’s other special features, it also includes a USB 2.0 port, to which an external storage device may be attached. Because the Killer NIC supports BitTorrent, FTP and other file transfer activities on-board, this adds storage space that the card can manage directly. The feature also allows for file transfers to and from the PC to occur through this network interface without involving the primary CPU in such activity.

At the TCP/IP level, a special Windows driver that works with Windows XP and Windows Vista permits Windows to offload TCP/IP processing onto the Killer NIC, bypassing the normal Windows protocol stack up through the transport layer for UDP (gaming protocols) and checksum offload for TCP. Bigfoot Networks makes much of the Killer NIC’s ability to take on protocol and network processing, thereby leaving the primary CPU and graphic channel better able to handle complex 3-D game graphics. Indeed, there’s something to be said for moving most interrupts and I/O activity associated with TCP/IP networking onto a NIC, thereby allowing the CPU and graphics channel to concentrate more of its resources on the interrupts and I/O activity associated with rendering complex game worlds and scenery. The net result is supposed to be a more fluid and responsive gaming experience. We observed the improvements to the gaming experience ourselves when comparing the behavior of our test systems playing identical games through identical network connections, where the only difference was the presence or absence of a Killer NIC.

Other capabilities that the M1 Killer NIC confers include the following:

• Hardware Firewall: Bigfoot Networks provides a download for a firewall that runs on the card. Based on the well-known Linux/UNIX iptable code, it lets users run the firewall on this NIC, thereby offloading that processing burden from the CPU as well.
• Support for "in-game" applications on the NIC: An increasing number of MMORPGs and first-person shooter (FPS) titles include support for running BitTorrent, FTP, Game Patcher and other code while the game is in use. Bigfoot also offers downloads for FTP, BitTorrent, Telnet and Game Patcher client software on its Website. These facilities can use the USB port to store downloads to an attached drive while the game is running, and then later transfer such files from that drive to other drives on a PC. Priority handling for game traffic also means that gamers won’t notice performance hits as a result of such background access activities.
• Some games even include support for a headset and voice channel for team communications as well. So Bigfoot Networks has teamed up with DiamondWare to support what they call "proximity-based 3D positional voice" in games that use the DiamondWare API. Killer NIC owners can download an FNA Voice Beta for use with the card and compatible games (works with any USB-compatible headset or sound card).
• In early April, 2008, Bigfoot announced support for a Hardware Bandwidth Control tool for the Killer NIC. This software lets users set priorities for foreground and background applications in the Windows environment. It makes sure that games continue to get priority access to the Internet, even if scheduled or event-triggered network access occurs from other applications while play is ongoing. The software widget also lets users set application priority and also limit bandwidth use on a per-application basis, including chat, email, PunkBuster and various automatic updates like those for Windows, Adobe, QuickTime and so forth.

The Bandwidth tab in the Bandwidth Control tool lets users limit upload and download bandwidth or keep settings at the default level of "Unlimited."

For developers (and Linux bitheads), Bigfoot even offers the source code for the Killer NIC’s Linux kernel, its compiler and related tools. Interested third parties can use these tools to build their own applications for the Linux runtime on the Killer NIC. For now, however, this is more than enough detail about the Killer NIC itself. In the section that follows, we provide a description of the two test systems we built for our testing of the Killer NIC, along with a list of games we used and our testing methodology, to help readers understand what our results really tell them.