Introduction — continued
Hardware-accelerated Gigabit Ethernet with a firewall Other chipset makers are deemphasizing networking capabilities, preferring to let the newfound bandwidth of PCI Express enable third-party network controllers to handle those duties. NVIDIA, on the other hand, is extending its emphasis on integrated networking. The nForce4 has a Gigabit Ethernet controller and NVIDIA's own home-cooked firewall software, as did the nForce3 250Gb before it. New this time around is actual hardware-level acceleration of packet handling, both for basic TCP/IP communications and for the stateful packet inspection conducted by the firewall. The nForce4 includes logic, designed in-house at NVIDIA, to offload such chores from the CPU. NVIDIA's marketing types have dubbed this feature ActiveArmor. Despite the name, it is possible to use ActiveArmor's TCP acceleration while NVIDIA's firewall is disabled.
Eight-channel AC'97 audio Another highlight, or perhaps the lowlight, of the nForce4's feature set is audio. While building its hardware-accelerated networking capabilities, NVIDIA has moved in the opposite direction for audio, dropping the DSP-accelerated SoundStorm solution from the nForce3 in favor of basic AC'97 audio. The nForce4 won't resurrect SoundStorm, and NVIDIA hasn't elected to support Intel's new High Definition Audio standard on nForce4, either, so the nForce4 can't handle the higher sample and bit rates that standard brings. The nForce4 does have the ability to feed eight channels of AC'97 audio, however, and NVIDIA's audio drivers support 3D positional audio via DirectSound3D and EAX.
A 1GHz HyperTransport link Despite rumors to the contrary, NVIDIA says the nForce4 will feature a 1GHz HyperTransport link to the CPU. In fact, the reference board that NVIDIA supplied us for review had 1GHz HyperTransport link option in the BIOS, and we turned it on for testing without suffering any negative consequences.
nTune tweaking software NVIDIA has long been pushing its System Utility as a means of tweaking and overclocking nForce-based motherboards, but not all motherboard makers provided the right hooks in the BIOS to make this utility fully functional. For the nForce4, NVIDIA has renamed the utility to nTune and given it an auto-overclocking feature similar to the one in NVIDIA's graphics drivers. The software will put the system through a series of tests to determine a "safe" set of overclocking settings. NVIDIA says the goal isn't to squeeze every last possible ounce of performance out of the system like one might get with manual tuning, but to provide a quick, automated way to get 90% or so of the way there. I tried out nTune on the NVIDIA reference board, and after a lock-up and several restarts, it settled on a 210MHz HyperTransport speed, raising the clock speed of my Athlon 64 4000+ from its stock 2.4GHz to 2.52GHz.
nTune can also aim for specific goals, like best graphics performance or "silent tuning" that might be more appropriate for home theater PCs or word processing work, and it can save and manage various profiles with these settings. The nTune software also has a monitoring tool to keep track of fan speeds and temperatures, plus a BIOS flash update tool that works inside of Windows. I'm curious to see whether NVIDIA can convince motherboard makers to support nTune; they tend to prefer to provide their own monitoring and tweaking software.
NVIDIA will be making things even more complex by offering three different versions of the nForce4. The nForce4 Ultra, which we're reviewing here, will be the middle-of-the-line version aimed at motherboards in the $100 to $150 range. The nForce4 SLI will have the same basic set of features, but it will, naturally, go on motherboards with multiple graphics slots for SLI. Expect those boards to cost $200 or more. And the cheapy version of the chip, just dubbed "nForce4" and nothing more, will be aimed at $50 to $80 mobos for Socket 754-based Athlon 64 and Sempron processors. The vanilla flavor of nForce4 will lack some of the fanciest features, including support for 1GHz HyperTransport speeds, SATA II transfer rates, and ActiveArmor acceleration. It will, however, still include a Gigabit Ethernet controller, firewall, and all the rest.