- Introduction
- PCI-Express x16 Basics
- ATI X-Series Overview
- Conclusion
- For Further Research
Like this article? We recommend
Like this article? We recommend
Like this article? We recommend
ATI X-Series Overview
ATI's initial PCI-Express GPUs include six models, using three different GPU series:
X800 XT Platinum Edition
X800 Pro
X600 Pro
X600
X300
X300 SE
These GPUs have the following common features:
Dual-monitor support: one VGA and one DVI port
TV-out support (S-Video port)
PCI-Express x16 connector
DirectX 9.0 compliant in hardware
The differences between them are revealed in the following sections.
RADEON X800 GPUs
The ATI X800 GPUs represent the top of ATI's initial crop of PCI-Express components. The X800s are designed to provide up to twice the performance of ATI's AGP flagship, the Radeon 9800 series, thanks to:
more pixel pipelines and vertex shader pipelines than their predecessors
support for OpenGL 2.0 (programmable shaders)
faster core clock and memory subsystems
GDDR-3 memory, the fastest memory used by video cards
Initially, ATI offers two X800 GPUs, but a third, the X800SE for use by OEMs, is likely to be introduced in the future. Table 1 shows how the Radeon X800 PRO and Radeon X800 XT Platinum compare to the ATI Radeon 9800 series.
Table 1 – Radeon X800 Versus Radeon 9800
GPU |
X800 PRO |
X800 XT Platinum |
9800 XT |
9800 PRO, AIW 9800 |
9800 |
|
Interface |
PCI-Express x16 |
PCI-Express x16 |
AGP 8x/4x |
AGP 8x/4x |
AGP 8x/4x |
|
Memory Bus Size |
256-bit |
256-bit |
256-bit |
256-bit |
256-bit |
|
Memory Size |
256MB |
256MB |
256MB |
128MB |
128MB |
|
Core Clock Speed |
520MHz |
475MHz |
412MHz |
380MHz |
325MHz |
|
Memory Type |
GDDR-3 |
GDDR-3 |
DDR-II |
DDR-II |
DDR-II |
|
Memory Speed |
450MHz |
575MHz |
365MHz |
340MHz |
290MHz |
|
Pixel Pipelines |
16 |
12 |
8 |
8 |
8 |
|
Vertex Shader Pipelines |
6 |
6 |
4 |
4 |
4 |
|
DirectX Support |
9 |
9 |
9 |
9 |
9 |
As you can see from Table 1, the use of GDDR-3 memory by the Radeon X800 series enables memory clock speeds to greatly increase compared to those available with the DDR-II memory used by the Radeon 9800 series. GDDR-3 memory's effective clock speed is actually twice that listed in Table 1, enabling the GPU to keep the greater numbers of vertex shader and pixel pipelines properly supplied with data.
Other factors which enable the X800 series to outperform the Radeon 9800 include enhanced versions of ATI's anti-aliasing and anisotropic filtering (SMOOTHVISION HD), compressed texture maps (3Dc), high-speed data transfer techniques (HyperZ HD) and video decoding and playback (SMOOTHVISION HD). The X800 GPUs are best suited to extreme gamers who prize performance above all else.
RADEON X600 GPUs
RADEON X600 GPUs represent the middle of the ATI PCI-Express pack, blending the performance of PCI-Express X16 with features inherited from the mid-range Radeon 9600 series. The X600 GPUs' main features include:
4 pixel rendering pipelines
2 programmable vertex shader pipelines
DDR memory
128-bit memory bus
SMARTSHADER 2.0, SMOOTHVISION 2.1, HyperZ III, VIDEOSHADER*
*To learn more about these technologies, see my article "The ATI RADEON 9800 and 9600 Series" http://www.quepublishing.com/articles/article.asp?p=339020
Table 2 compares the RADEON X600 PRO and X600 against the RADEON 9600 series.
Table 2 – Radeon X600 Versus Radeon 9600
|
GPU |
X600 PRO |
X600 |
9600 XT |
9600 PRO, 9600 AIW |
9600 |
9600SE |
|
Interface |
PCI-Express x16 |
PCI-Express x16 |
AGP 8x/4x |
AGP 8x/4x |
AGP 8x/4x |
AGP 8x/4x |
|
Memory Bus Size |
128-bit |
128-bit |
128-bit |
128-bit |
128-bit |
64-bit |
|
Memory Size |
128MB, 256MB |
128MB, 256MB |
128MB |
128MB |
128MB |
128MB |
|
Core Clock Speed |
500MHz |
400MHz |
500MHz |
400MHz |
325MHz |
325MHz |
|
Memory Type |
DDR |
DDR |
DDR |
DDR |
DDR |
DDR |
|
Memory Speed |
750MHz |
600MHz |
600MHz |
600MHz |
400MHz |
400MHz |
|
Pixel Pipelines |
4 |
4 |
4 |
4 |
4 |
4 |
|
Vertex Shader Pipelines |
2 |
2 |
2 |
2 |
2 |
2 |
|
DirectX Support |
9 |
9 |
9 |
9 |
9 |
9 |
As Table 2 makes clear, the X600 series is essentially a PCI-Express version of the Radeon 9600 series. Choose the X600 if you want mid-range game performance and solid business performance in the PCI-Express form factor.
RADEON X300
The ATI RADEON X300 series represents the low end of ATI's PCI-Express lineup. Cards based on these chips are more likely to wind up in OEM-assembled PCI-Express-based systems than as retail products. However, unlike the 9200-series RADEON GPUs (which are the current low end of ATI's 9xxx series for AGP slots), the X300 and X300SE, like their more powerful siblings, are full DirectX 9 compatible GPUs.
The major features of the X300 series include:
4 pixel rendering pipelines
2 programmable vertex shader pipelines
DDR memory
128-bit or 64-bit memory bus
SMARTSHADER 2.0, SMOOTHVISION 2.1, HyperZ III, VIDEOSHADER
Table 3 shows how the RADEON X300 series compares to the ATI 9200 series.
Table 3 – Radeon X300 Versus Radeon 9200
|
GPU |
X300 |
X300SE |
9250 |
9200 |
9200SE |
|
Interface |
PCI-Express x16 |
PCI-Express x16 |
AGP 8x/4x |
AGP 8x/4x |
AGP 8x/4x |
|
Memory Bus Size |
128-bit |
64-bit |
64-bit, 128-bit |
128-bit |
64-bit |
|
Memory Size |
64MB, 128MB, 256MB |
64MB, 128MB |
128MB, 256MB |
128MB, 256MB |
128MB |
|
Core Clock Speed |
325MHz |
325MHz |
240MHz |
250MHz |
200MHz |
|
Memory Type |
DDR |
DDR |
DDR |
DDR |
DDR |
|
Memory Speed |
400MHz |
400MHz |
400MHz |
400MHz |
333MHz |
|
Pixel Pipelines |
4 |
4 |
4 |
4 |
4 |
|
Vertex Shader Pipelines |
2 |
2 |
1 |
1 |
1 |
|
DirectX Support |
9 |
9 |
8.1 |
8.1 |
8.1 |
As you can see from comparing Tables 2 and 3, although the X300 is the lowest-performing PCI-Express GPU made by ATI, it still rivals the RADEON 9600, and far outstrips the RADEON 9200 with full DirectX 9 support and faster clock speeds. Given the continued movement to DirectX 9 in gaming and the planned use of DirectX 9 graphics in the upcoming Longhorn version of Windows, it's very useful to have DirectX 9 support at all levels of ATI's PCI-Express product line.