XFX 7800GT XXX Video Card Review :: XXX Features

01-25-2006 · Category: Hardware - Video Cards

By Doc Overclock
7800GT XXX Edition
 
Brand XFX
Model 7800GT XXX Edition
Graphics Chip G70
Graphics Memory Type DDR3
Memory (MB) 256
Graphics Core Clock (MHz) 450
Memory Clock (MHz) 1050
Memory Speed (ns) 2.0
RAMDAC Frequency (MHz) Dual 400
Active Cooling on Graphics Chip Yes
Heatsink on Memory Yes
Video Capture Yes
Ports
Dual Monitor Support Yes
VGA Out DVI-I, DVI-I
Video In and Out S-Video Out
Package and Support
Printed Manual Yes
Driver CD Yes
Performance Tool Software Coolbits
Major Games Far Cry
X2 The Threat
Moto GP2
Major Software Tenomichi 3D Edit
VR Glasses No
DVD Player Software None
Video Recording Software None
  • 0.11 micron process
  • 302 million transistors
  • DirectX 9.0c
  • Pixel Shader 3.0
  • Vertex Shader 3.0
  • SLI
  • PureVideo
  • Intellisample 4.0
  • HDR
  • Transparency Supersample and Multisample Antialiasing
  • PCI Express x16
  • G70

XFX 7800GT XXX Video Card Review Card I/O

Card I/O

XFX 7800GT XXX Video Card Review Fan

Fan

XFX 7800GT XXX Video Card Review Power Connection

Power Connection


Microsoft first introduced the DirectX 9.0 API in late 2002; subsequently the release of the ATI RADEON 9700 Pro and the announcement of the GEFORCE 5800 Ultra came into play supporting these new features. It's hard to believe it's been almost 3 years since the release of both those cards and both ATI and NVIDIA have made tremendous strides in developing cards that take maximum advantage of the API. The key ingredients of the DirectX API are the Pixel and Vertex Shader features or (HLSL) High-Level Shader Language, which are the heart of DirectX 9. Programmable Shaders were first introduced with DirectX 8.0 and steadily improved upon, which has been advantageous to the gaming industry. The card uses a cooper heatsink arrangement that not only works well it looks good as well. The card has a really cool color design that incorporates a neon green and black combination that is very eye pleasing and NVIDFIA oriented.


XFX 7800GT XXX Video Card Review Angle Shot

Angle Shot

XFX 7800GT XXX Video Card Review PCIe interface

PCIe interface

XFX 7800GT XXX Video Card Review Cooper Heatsink

Cooper Heatsink


NVIDIA's G70 series is their second generation of Shader Model 3.0 product. They introduced the GEFORCE 6xxx series in the spring (April 22nd) of 2004. The GeForce 6800 Ultra, 6800GT, 6800, GeForce 6600GT, 6600, 6200, 6200 with Turbo Cache and 6150 make up the primary members of that generation of video card. Today, millions of chips based upon that architecture have been sold and are working away in someone's PC. Key features of the G70 Pixel Shader 3.0 specification include nearly unlimited pixel Shader program length, dynamic branching and looping of the pixel Shader. The 7800GT is very powerful in MADD (Multiply Add) operations, being up to 50% faster in such operations than the 6800GT. MADD instructions are the most commonly used instructions in the Pixel Shader process.


XFX 7800GT XXX Video Card Review Back Shot

Back Shot

XFX 7800GT XXX Video Card Review Heatsink Rear

Heatsink Rear


Pixel Shaders are small programs performed on pixels to perform graphics effects. One of the most common uses of Pixel Shaders in games today is by way of beautiful water, but that was true in 2001 with the introduction of the first Programmable Pixel and Vertex Shader hardware in the form of the GeForce3. Of course with the advent of Pixel Shader 2.0 and 3.0 now with hardware support, the game developers have had more tools to work with, which brought more visual effects as well. Splinter Cell Chaos Theory uses advanced skin Shader for character with subsurface scattering and improved light bleeding, high internal precision and tone mapping. F.E.A.R is another game that uses Pixel Shaders to do real-time per pixel lighting, shadow volumes and advanced Shaders.

Vertex Shaders are small programs performed on vertices to give other special effects. Common uses of Vertex Shaders in the past have included keyframe animation, vertex blending with up to 4 bones, and more. Of course, we're talking about Vertex Shader 3.0 hardware here. Modern games like Splinter Cell Chaos Theory use VS to do pre-computed displacement mapping. F.E.A.R uses Vertex Shaders 3.0 to do normal mapping. NVIDIA focused on improving image quality with their 7xxx series in antialiasing. Theirs was the first card available to support antialiasing for transparent textures like the insides of a wire fence or dense vegetation. Transparency Antialiasing helps aliasing in those textures by using supersampling or multisampling in the alpha channel textures that are transparent. It works especially well in games like Half Life 2 where the fences can look like a big moiré mess on a card that doesn't support this or Adaptive Antialiasing.

The human eye can distinguish between thousands of color contrasts. The dynamic range of light on most monitors is limited to 255:1 or 8-bits per color channel. The 7800GT supports HDR with up to 16-bits per color channel or a dynamic range of 65,535:1. If you have ever gone from a dark room to bright sunlight outside, you know the effect blooming can have on your vision and how it blinds you momentarily. HDR makes things look more natural by having a wider range of contrasts across the color spectrum. The 7800GTs have 20 pixel pipelines but only 16 ROPs. A ROP is the outputted pixel. Pixel fillrate is not likely to be a problem for the near future, with the XFX 7800GT having a fillrate of over 7 Gigapixels and a textel fillrate over 9 gigabytes, this is likely to be the case. ATI is also heading this way as their "R580" card will likely have 16 ROPs and 48 pixel processors.


XFX 7800GT XXX Video Card Review SLI Finger

SLI Finger

XFX 7800GT XXX Video Card Review Top of Card

Top of Card


SLI was first invented by 3DFX and the acronym stood for Scan Line Interleave. It's now been 5 years since 3DFX went bankrupt. NVIDIA bought many of the assets, the IP, and about 100 of the existing employees. Late last year NVIDIA decided to bring about the second coming of SLI. SLI in this case stands for Scalable Link Interface. To enable SLI on an NVIDIA card you need a few things, first, an nForce4 SLI motherboard, two NVIDIA based video cards with the same model, and a good PSU (Power Supply Unit). NVIDIA's SLI has 3 modes SFR, AFR and compatibility mode. Single Frame Rendering has both cards working together to output a composite final scene.

The workload of the cards can vary, depending on the application and the game profile, as different parts of a scene may require more GPU power than the other in some instances. AFR has each GPU working on successive frames. Frame 1 is on GPU 1 Frame 2 is on GPU 2 and so on. The 7800GT from XFX has a clock speed of 450 MHz/1.05GHz core/memory clock by default. NVIDIA has set the reference speeds to 400/1.0 GHz. This makes the XFX cards I'm reviewing here overclocked by 50MHz for the core and 50MHz for the memory. The XFX XXX 7800GT is lower clocked than EVGA's 490MHz but higher clocked than many 7800GTs around. The Memory bandwidth on the 7800GT from XFX is 33.6GB/second. These features are best observed to the end-user when playing games or encoding video, otherwise they are mainly just a bunch of numbers that represent the technical aspects of the card.