Hard Numbers

Taking a quick peek at the numbers reveals that NVIDIA didn't change very much in their specifications, but obviously the changes that were made have had a significant impact on the performance of their new line of cards. The main changes that you will notice are that the Vertex pipelines have been bumped up from 6 on the previous generation of NVIDIA cards to 8 on the current model. This becomes important when you realize that it's the Vertex engine and pipelines that feed the processed geometry to the Pixel engine.

Pixel Pipelines have been increased from 16 on the 6800 Ultra, to 24 on the 7800 GTX, allowing more pixels to be shaded, textured, blended, etc. and then output at the same time. The increased number of Pixel Pipelines also allows pixels to remain in the pipeline longer for more complicated upcoming texturing techniques without compromising the speed at which the gameplay is currently being rendered.

NVIDIA launched the GT version of the 7800 card on August 11th, 2005 at Quakecon. The GT is a little less potent than the GTX version, but still reigns above it's competition in frame rates and technology. The 7800 GT has slightly reduced clock speeds and numbers of Pixel pipelines, but still includes Shader Model 3 technology, HDR lighting, is SLI mode capable, and is all wrapped up in a single slot solution.

The Cost of Speed

With price points of $449 for the 7800 GT, and $599 for the full blown 7800 GTX, the casual gamer may decide to wait a while to upgrade to this new series, but for the hardcore gamer, there is no need to wait at all. History has taught us that, although video card companies release new technology video cards, this does not mean that you can get them.

Many, if not all, of the past releases have left gamers wandering the aisles of their local PC hardware stores disappointed in the fact that, although they had the cash, and the desire... there was no product to be found. In some cases it took months for the cards to become available, and even then, in very limited numbers. NVIDIA made sure that this was not the case with the 7800 launch. By the time the ads started appearing in magazines and the buzz hit the web, PC stores and online e-tailers were already stocked with the high-powered green goodness that is the NVIDIA 7800 GTX.

The Power of 3

NVIDIA has decided to help market the 7800 Series GPU's with a campaign entitled "The Power of 3". What is "The Power of 3"? Good question! The 3 items being referred to are the 3 technologies that aren't readily available through any competitors cards.

1. Shader Model 3.0
2. High Dynamic-Range
3. Scalable Link Interface

Let's examine these closer:

Shader Model 3.0

Shader Model 3.0 (or SM 3.0 as it's commonly known), is the latest generation of pixel shading technology introduced through DirectX 9.0. SM 3.0 adds several features and enhances some which were found in the previous generation. Most notably is the increase in Shader length instructions which has been increased from 256 in SM 2.0 to 65,535 in SM 3.0.

Much has been written about the value if increasing the shader instruction length vs. simply increasing the amount of passes needed to complete an operation, but in the end it would seem that each video chip manufacturer will eventually be upgrading to the SM 3.0, NVIDIA just happened to be the one to do it first. Both the XBOX 360 and the PlayStation 3 are slated to use SM 3.0 in their graphics platform.

Table from Microsoft's website detailing the changes between Shader Model 2.0 and Shader Model 3.0:

High Dynamic-Range

High Dynamic-Range (HDR) lighting is a new technology which helps to blur the lines between reality and rendering. HDR Lighting takes into consideration the light balance of all areas of the render and appropriately applies lighting brightness to objects based on their real-time counterparts. For example, the moon would look much brighter if you were walking through the woods than if you were in the middle of a city due to the lack of other lighted objects diluting the brightness.

In another example, if you were walking out of a darkened room and into the sunlight, everything would appear much brighter than it really is. Only as your eyes adjusted to the glare, would the details of your surrounding come back into focus. Game designers now have the tools to re-create this sensation. Games currently taking advantage of this technology are: Far Cry, Splinter Cell: Chaos Theory, the Painkiller Expansion pack, and the forthcoming Half Life 2: The Lost Coast single level add-on. As newer games are released to the market, it is a sure bet that they will do their best to incorporate this incredible new technology as well.

SLI - Scalable Link Interface

SLI has been discussed, at length, by just about every tech website online. NVIDIA's new implementation of SLI (Scalable Link Interface this time around), is a revolutionary approach to combining multiple GPUs in a single system to scale performance. NVIDIA® SLI™ multi-GPU technology takes advantage of the increased bandwidth of the PCI Express™ bus architecture, and features intelligent hardware and software solutions that allow multiple GPUs to efficiently work together to deliver high performance graphics display on one monitor. For more on SLI technology, please see our ASI Technical Newsletter from October, 2004 here .

Recent SLI information updates from NVIDIA

• SLI can enable multi-GPU rendering on all applications
• NVIDIA SLI supports the following modes: SFR (with dynamic load balancing), AFR (Alternate Frame Rendering), AFR2 (modified version of AFR), SLI16x (16x AA), and SLI8x (8x AA)
• Driver updates being released shortly by NVIDIA will remove constraints that currently limit SLI customers to using identical graphics cards
• SLI support on all games out of the box. Optimized game settings developed by NVIDIA testing labs for over 100 games means enhanced gameplay with SLI cards, mostly based on AFR technology for the best scaling performance

Benchmarks

NVIDIA and their launch partner XFX were good enough to supply us with a retail boxed GeForce 7800 GTX (model number PV-T70F-UNF7) (ASI SKU# 38219) for testing purposes.

With the performance levels that we've seen, it's almost scary that XFX also has a higher version of this card available. The XFX GeForce 7800 GTX (model number PV-T70F-UND7) (ASI SKU# 38978), is overclocked to 490MHz on the engine side and 1.3GHz on the memory side. We're not sure what game would be able to take full advantage of this kind of power and speed... but we'd be lying if we didn't say we'd like to find out.

In the noise department, or I should say "lack of noise department", the XFX GeForce 7800 GTX is highly impressive. This unit is probably the quietest high-end video card that I've tested in the past several years. Sitting on my Intel D945PVS motherboard during testing, I was hard pressed to hear the fan on the video card at all. The stock Intel CPU fan was actually louder than the video card cooling unit.

While running the benchmark tests, we tend to ignore manufacturers guidelines as to what settings to use and what items to tweak in the control panel, or in the applications themselves. There are so many different variables which run between the NVIDIA and the ATI based cards that it's very hard to be fair when tweaking different settings. We use the baseline driver defaults and the baseline testing application defaults in order to achieve the fairest scores possible.

Now on to the numbers: In addition to the XFX GeForce 7800 GTX and the ATI AX850XT Platinum, our testing setup consisted of the following:

3DMark '05

The de-facto standard for benchmarking is Futuremark's 3DMark program. In addition to giving us something new and cool to show off every year at our ASI Technology Expo, it also tortures the latest and greatest video cards into submission. When you watch as a $400+ video card attempts to render a scene and is brought down to 2-3 FPS, you know that there is some serious number crunching going on. Futuremark always delivers the goods when it comes to benchmarking.

A slight performance lead for the 7800 GTX card is seen, which you'd expect since the technology is newer than what is currently available from ATI.

SPECViewperf 8

More of a "real world" test designed by the Standard Performance Evaluation Corporation (SPEC). This software was designed to establish, maintain, and endorse a standardized set of relevant benchmarks to test the newest generation of computer hardware.

Results from the SPECViewperf test are split down the middle, with the ATI card leading by a good margin in a few areas.

Doom 3

When it was released, Doom 3 had people running, not walking, to their local PC shops to purchase new video hardware. When it came to video requirements, with this game only the strong survived.

Although close at lower resolutions, you can clearly see that, as screen size increased, so did NVIDIA's performance lead in this groundbreaking title.

FarCry w/1.32 Patch

FarCry is a very graphically stunning game. The textures and shading throughout the game are incredible, and with the SM 3.0 enhancements it can be pretty demanding on your hardware as well.

ATI clearly came out the winner in the FarCry benchmark test which came as sort of a surprise. Two factors which come to mind in the results would be that a.) the game may have been optimized for ATI hardware. or b.) NVIDIA's use of the SM 3.0 enhancement may be slightly hindering their pure performance numbers. Considering that the human eye doesn't really notice changes which are above 30 FPS, I think 60+ FPS with better quality graphics still works out just fine.

CryTek released FarCry patch version 1.33 on 8/11 which was too late to release for this article. I'd be surprised if there weren't changes in the patch which would better represent the cards on a more level playing field.

NVIDIA has once again taken it's place at the top of the hill in the video card wars. Their new 7800 series has not only increased in power and performance, but has also reduced power requirements, noise levels, and maybe most importantly for the customers, has actually materialized when they said it would.