NVIDIA has come quite a long way with their nForce chipset. From the original version that arrived a bit late to the scene causing it not to revolutionize performance and computing, but rather to be just another chipset in the face of the competition. This was followed by the nForce 2, which produced a much better showing than the original nForce by actually being released on time and having some features and functionality that set them aside from the competition. While the nForce 2 surely wasn't without a few problems, I can not say that there is any single chipset that has been released to date that was not. Next came the nForce 3 which marked a beginning to the 64-bit computing era and a few new features such as a built-in hardware firewall.

Now NVIDIA is gearing up to release their new nForce 4 chipset. Following with their tradition of adding at least a little something new to the mix, the nForce 4 chipset will be AMD's first PCI Express chipset for the Athlon 64 family of CPU's. Alongside the new PCI Express base of the nForce 4, other major features include that ability to use SLI with supporting NVIDIA graphics cards, a continuation of the built-in hardware firewall, methods to easily optimize the performance of your PC, and also methods for safely storing your electronic information. There are three versions of the nForce 4 that will be released. Following is a table of these three versions and their features.

Product Line	CPU Support	Target Market	Expected Price Point (USD)
nForce 4 SLI	Athlon 64 FX and Athlon 64	High-end Enthusiast	Less than $200
nForce 4 Ultra	Athlon 64 FX and Athlon 64	Enthusiast	$100 - $150
nForce 4	Athlon 64 and Athlon 64 Sempron	Value/Mainstream	$55 - $80

It should be pretty obvious based on the table what kind of features each of these boards will support. The nForce 4 SLI and nForce 4 Ultra are essentially the same boards, supporting Socket 939, with the exception of the nForce 4 SLI being capable of using two NVIDIA SLI supporting graphics cards.

The nForce 4 will obviously be the basic value board much like what PC manufacturers include in the majority of their systems, and will be offered in both Socket 754 and likely Socket 939 as well.

nForce SLI

The first major feature of interest is the new SLI support that comes with the nForce 4. Given that SLI is an NVIDIA specific technology, it would stand to reason that they would be the first to release a motherboard chipset that supports this technology for the AMD platform. I'm quite sure that most of you reading this already know what SLI is, but for any that don't, it is a technology developed by NVIDIA that allows the use of 2 PCI Express x16 graphics cards, via a bridge connector, in one system to boost performance by essentially assigning a portion of the screen to each graphics card, rather than having one graphics card responsible for the entire screen. While a single card will operate at the full PCI Express x16 specification, two cards will operate on dual PCI Express x8 pathways.

To give the best performance, NVIDIA has built the SLI technology directly into the MCP giving it direct access to the system bus, without the need to go through unnecessary components to do its job. Think of it as load balancing, as each card should be doing the same amount of work any given time.

It would stand to reason that the use of SLI, especially with a couple of high-end GeForce 6800 Ultra's or 6800 GT's, will greatly improve the performance of your games, and that NVIDIA will probably have the best performing solution for this technology, though that remains to be seen when we actually get some hardware to test this with. This will definitely be a feature that some high-end gamers will be quite interested in, and depending on the pricing, might allow some enthusiast to use as well.

It's important to realize that you will not be required to use two 6800 Ultras for SLI, though that would certainly be the fastest setup, albeit the most expensive. Dual 6800 GTs and the upcoming 6600 GTs will also be supported, which will cover the sub-$200 to $400 to $500 market. While those are the planned price points, you'll obviously have to double those numbers for SLI. While two cards are required, they do not necessarily have to be from the same manufacturer. So long as the card(s) (as well as the motherboard) pass NVIDIA's SLI certification, in theory, you can have an ASUS and MSI card for example in the same system. Ideally, you'll want the same clock speeds (and in our opinion, the same manufacturer), or else the SLI setup will default to the lowest common denominator. Both cards have to be from the same family however, as you cannot match a 6800 Ultra with a 6600 GT.

To get an idea how much performance we may see with SLI, take a look at the following chart demonstrating Doom 3 performance:

	Single	SLI
6800 Ultra	42.4	71.7
6800 GT	37.9	65.2
6600 GT	17.3	32

While the above numbers are direct from NVIDIA, it does present to us some interesting information. What is obvious is that SLI gives a significant performance advantage over a single GPU solution, within its own class. What is interesting is the SLI 6800 GT's performance which is a lot higher than the single 6800 Ultra, and not too far off from the Ultra's SLI numbers. While the 6600 GT SLI setup trails the 6800 GT's single performance in Doom 3, the numbers NVIDIA provided show it outperforms the lone 6800 GT in Halo and 3DMark05.

Keep in mind that although two NVIDIA cards are required for SLI, the upcoming boards will of course support single cards from any manufacturer. These cards will have to be PCI Express based though, as the nForce 4 (all versions) will be dropping AGP all together. We say it again... don't hold your breath for any creative tinkering by motherboard makers... AGP is gone. One other note is there won't be any integrated graphics with the initial release of the nForce 4. Based on market studies, AMD buyers tend to seek out discreet graphics solutions, and as PCI Express ramps up, there may be an integrated solution down the line.

NVIDIA Firewall

Another of the features of the nForce 4 is the improved integrated hardware firewall. Just as with the SLI technology, the firewall is built directly into the MCP to reduce system overhead. Unlike your Linksys or Dlink broadband router which relies mostly on NAT for firewall protection, the NVIDIA nForce 4 firewall uses what NVIDIA calls ActiveArmor secure networking engine. This solution, according to NVIDIA, makes this the industries first true hardware-based PC firewall.

Editor's Note - March 14, 2005: We received an email worth sharing regarding comparisons to D-Link's products. Here's the email in full, unedited in content:

D-Link routers all use what is called Stateful Packet Inspection or SPI. Stateful Packet Inspection looks at every packet that comes and goes from the internal network to the Internet and back. If any of the packets are flagged as not requested by the network or looks malicious, the router drops the packet. If you were to read the technology briefing (linked here) from NVidia, they describe their ActiveArmor technology exactly like Stateful Packet Inspection.

They also position their ActiveArmor as being a better solution than software firewalls. They don't mention hardware firewalls. The reason being is that they probably know we use SPI, which what ActiveArmor is. So, what this means is that NVidia's ActiveArmor technology is great for users that only have one PC connected directly to a cable modem. This would give them the same protection as a D-Link router, with only one PC connected, but if somebody plans on having more than one PC or gaming consoles, etc., they would want a D-Link Gaming Router.

This technology also allows the firewall to operate without using the system CPU for overhead, so unlike a software firewall, the nForce 4 firewall will not bog down other computing tasks by requiring the main CPU to process packets. The nForce 4 firewall also supports remote access, configuration, monitoring, command line interface (CLI), and WMI scripts. These features allow you to have a great deal of control over how the firewall operates should you desire, and are all able to be configured through wizards so almost everyone should have little trouble in configuring their firewall.

Another feature that makes the nForce 4 firewall quite useful as opposed to standard software firewalls or firewalls integrated into standard broadband routers is the technology in use to filter packets. The first advantage over software firewalls is that the nForce 4 firewall is activated the instant that the network connection becomes active, so you are protected from the instant that the operating system loads. And unlike the standard broadband router which primarily uses NAT as its method of protection, the nForce 4 firewall uses stateless and stateful methods to filter packets. Though the actual nuts and bolts of stateless and stateful packet filtering are not the focus of this article, what they basically do is filter packets based on rules in place for the TCP or UDP port that they are being transmitted over, their source or destination address, and some other criteria. The actual difference between stateful and stateless packet filtering is essentially that in stateless packet filtering, every single packet that passes through the network adapter must be checked against the rules in place. This can lead to a sever drop in performance when there are a lot of rules that each packet must be checked against. Stateful packet filtering, on the other hand, uses the idea of connections to filter packets. Rather than filter every single packet that passes through the interface, packets are only tested when the connection to a specific host is initially created.

Also included is an Intelligent Application Manager, which allows you to specify applications that are and are not allowed to access the network, much like other software firewalls. This feature uses alert messages much like those in ZoneAlarm and other software firewalls to notify you when applications attempt to access the Internet or your computer.

It may be important to note that on the mainstream/value nForce 4 chipset, while the firewall is fully supported, the ActiveArmor technology is not. This more than likely means that more CPU overhead will be involved when using the hardware firewall on a value nForce 4 motherboard than on one of the higher end Ultra or SLI versions. In other words, on both the nForce 3 250Gb and nForce 4 (value), the firewall is hardware optimized via software. The nForce 4 Ultra and SLI are hardware accelerated via ActiveArmor.

Serial ATA 3Gb/s

NVIDIA has also beefed up the Serial ATA performance on the nForce 4. Much like the way Dual Channel memory functions, NVIDIA has implemented two disk controllers into the MCP which gives data two independent paths to travel to and from system memory, which effectively doubles the bandwidth from 1.5 Gb/s to 3 Gb/s. This should give a decent speed boost to transfers to and from the hard drives, however, that is another feature that we will have to wait and see when we get a review sample in our hands.

To better understand this, the drives need to be capable of operating at the 3Gb/s supported by the controllers. The goal of the dual controller setup is to alieviate the bottlenecks that could occur in a single controller environment. In this scenario, if a drive goes through some major disk thrashing, the controller could get bogged down dealing with said drive, slowing down the other drives in the chain. In a dual controller situation, this becomes less of a problem as the other controller will allow the connected drives to operate at full capacity.

NVIDIA has also enhanced their raid configuration with Drive Alert software to allow for simple configuration, maintenance, and monitoring of your raid array and drive status. This feature also notifies you when a drive fails, and even tells you which SATA port that drive is plugged into so that you can easily replace the failed drive without having to go through the hassle of figuring out what drive actually went bad (click here for sample image). In the linked image, you can see that all your SATA connections are displayed, and the problem connection is highlighted in order to assist in troubleshooting.

Morphing is another interesting technology offered by the new controller setup. With the included software, it is possible to expand a striped array via Windows. In the past, if you had a striped array across two disks, the only way to add another drive was to backup, break the array, rebuild and reinstall Windows. Now, simply add the new drive, which Windows will recognize, and use the software to expand the array. The time it takes will vary depending on the speed of your hardware, but it will be much faster and convenient with the morphing technology.

Benchmarks provided by NVIDIA show 4 disk raid arrays performing around two times as well as competitors with sequential 256k reads and writes. Tests done on 2 disk arrays show performance is only slightly above that of competitor products. However, we do not have any of this hardware in hand for testing, so while it looks good on paper, we don't know how this will perform in real-word applications such as gaming and video editing, which are the types of tasks in which performance really matters to the end user.

Native Command Queuing (NCQ) is fully supported by NVIDIA's MCP. For those of you unfamiliar with how NCQ works, this is a feature that can only be found in native SATA hard drives that follow the SATA II specifications. Unlike Legacy Command Queuing (LCQ), NCQ works by allowing a drive to process multiple commands at the same time. These commands can be rescheduled or reordered on a whim, and can also issue new requests while the drive is retrieving data from the previous request. As we've investigated last week, NCQ will not make a huge difference in todays desktop applications, but the potential is there.

It is also important to note here that the value version of the nForce 4 does not have the dual disk controllers, and is only capable of 1.5 Gb/s bandwidth, unlike the 3 Gb/s on the Ultra and SLI versions. While the Ultra and SLI support PATA, SATA-I and SATA-II, the advanced features of the new controllers only work with PATA and SATA-I on the value nForce 4.

NVIDIA nTune

And of final note is the nTune software that will be available on the nForce 4. nTune allows you to easily optimize the performance of your system through a number of different paths. The nTune software allows you to create profiles for the types of tasks you are doing with your PC, which means that you can create a hardware profile for gaming, and another one for writing word documents or watching DVDs. Each of these hardware profiles will adjust your system performance so that it is at an optimal level for each of these tasks.

Also available is the ability to have the nTune software benchmark your system and automatically tune your settings based on the results of the benchmark. While I can see this as being a useful feature for the average computer user who just wants to get a little extra out of his system, or a casual gamer who wishes the same but doesn't want to go through and play with all the settings manually, I don't know that it will be of great use to computer enthusiasts. My reasoning for this is based on other such software that has been available, and also due to the way that NVIDIA has to have this software set up. First of all, one such similar software application as this that comes to mind is the ATI Overdrive technology. Using this, you can allow your video card drivers to automatically adjust the GPU core speed based on the temperature of the GPU core. While this gives a slight boost in performance, most enthusiast will realize that their GPU is capable of running at much higher speeds and remain stable, and as such, I'm sure that few enthusiast actually make use of this technology. NVIDIA has to make sure that they don't push a system too far with this software, because if system components started to overheat and die because a user used the nTune software, there would be a lot of angry consumers and this would most likely end up causing NVIDIA quite a bit of money to remedy.

By the same token, using the nTune software, NVIDIA does take a lot of the guess work out of tweaking, and while we're certain enthusiasts will want to do things manually, the software does do optimizations that a user normally may not think about, such as tweaking the MCP registry settings. NVIDIA claims that 90% of optimizations can be done via their software, so what else can it do?

The nTune software allows you to alter in real time settings pertaining to your GPU, CPU, MCP, RAM, Voltage, and system fans. Using this, you can overclock your CPU, GPU and set memory and system bus timings just as easily as you can use software like Powerstrip to overclock your video card. Simply drag the sliders, select a few options, and press apply. The software gives recommendations as to what you should set the various settings to, and uses a database of thousands of possible configurations to, if nothing else, give you a reference point on where to start tweaking. The built-in monitoring functionality also allows you to keep track of temperatures, speeds, and voltages that have been applied using the software to make sure that nothing gets out of hand.

One of the features of the nTune software that is stated is called Safe State Recovery. Safe State Recovery is all about pushing the system to the limits, and if a reboot happens restoring things back to working order. This works much the same way as MSI's CoreCenter and ABIT's µGuru software, except a little more advanced.

To better explain the above, think of it this way. Traditional overclocking by nature requires a user to edit a BIOS setting one at a time (at least, that is how it should be done). Once the desired tweaks are done, your PC is in an overclocked state from the get go. Now honestly, for the POST process and loading of Windows, do you really need the maximum OC? That is of course assuming you found the right settings. In the cases of a bad overclock, there is a strong chance of corrupting system files, forcing a possible repair or reinstall of the OS and repeating the whole process. Since the software is Windows based, the overclocked settings only kick in once Windows loads. If the system cannot handle the OC, it reverts to a stable setting, which is the whole point of the nTune tweaks.

Profiles can be setup in the nTune software as well. Just like the question posed earlier, do you need your maximum overclock and fans blazing at full speed when surfing the Internet? Likely not, and the nTune software allows you to setup a "quiet" mode for these tasks. At the same time, a profile can be set where fans can spin up when the CPU reaches a certain temperature.

System monitoring, the troubleshooting log, and the BIOS flash utility are all unique to NVIDIA and although individual apps might be able to do the same work, those other apps are not as extensive, nor as inclusive (and safe) as what they've built into nTune.

Once again though, this is all based on white papers and discussions with NVIDIA and I have no idea how well it works. We will have to wait until we are sent a review unit to actually test these features.

Board Partners

It's safe to say that you can expect boards from the usual suspects such as MSI, ASUS, Gigabyte and others. Basically, if they offered the nForce 3 250Gb, you should see nForce 4 models. While we're still waiting for official release dates, MSI has gone on record as saying they'll have products out by mid-November. Pictured above is a working sample of MSI's SLI K8N Diamond board.

Final Words

A couple of items some of you may have noticed that were not mentioned were DDR-II and SoundStorm. As it stands now, the memory controller is integrated into AMD's CPUs, so until we see a change there, ALL motherboards for AMD's Athlon FX/64 will be limited to DDR-I. Based on our reviews, this should not be a huge knock on AMD at the moment. SoundStorm was dropped with the nForce 3 because of the cost issue and return on investment. While we would like to see this feature come back, we wouldn't hold our breath for it. For those of you who have AGP cards, unfortunently, you will not be able to carry them over to the new platform. Before tossing those cards aside though, keep in mind that the nForce 3 250Gb will still be supported by NVIDIA, and although some hardware features differ, the software will be cross platform, thus keeping the previous generation viable for the time being.

We think that NVIDIA has a pretty firm grasp on how to make good quality, stable, and high performing chipsets for the AMD platform. Some of the features that are going to be available with the nForce 4 chipset sound quite promising, including the dual disk controllers for the SATA drives, the ActiveArmor networking security, and the wealth of options afforded by the nTune software. If all of this technology turns out to function as well when it is transferred from paper to silicon and applied to real-world applications, I believe that the nForce 4 will be well worth a look when you are looking at your options in the future. While it will require that you purchase a couple of other high ticket items such as a new CPU and video card, it looks like it should be a solid platform on which to build a truly awesome system.