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Wayne

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Trident XP4 Technology Overview
22nd August 2002
 
Introduction : Many people in the industry,
myself included, expressed some surprise when news broke on
the 5th of August that Trident were to dip a toe back into the
hostile waters that are today's graphics card market. With a
little more thought though perhaps this move isn't so surprising.
With a history in desktop graphics stretching way back to 1987
Trident were very much part of the primordial soup that gave
rise to the modern graphics accelerator and though they decided
to gracefully bow out and focus their attention elsewhere when
the market began to expand that doesn't necessarily mean they
don't have what it takes to rub shoulders with the best........
it's no guarantee that they do either.
I've tried hard to find the technical details
that might help us decide what the XP4 is potentially capable
of, and I have to admit I failed rather miserably. Hard facts
and figures seem a little hard to come by but we do have some
preliminary specifications to glance over.
What We Know : What we do know is that
Trident's XP4 will come in four flavours, a discrete notebook
solution and three desktop solutions known as the "T1",
"T2" and "T3". The GPU will be manufactured
on a 0.13um process using copper interconnects and features
an almost unbelievably low transistor count at 30 million.
We also know that Trident's maths don't quite
add up. They're claiming 70% of the performance of the new ATi
Radeon 9700 which based on current performance figures puts
it on a par with NVIDIA's Ti4600 yet they're also claiming 80%
of the performance of the Ti4600? Clearly we'll have to wait
and see the actual hardware before we know for sure but if I
had to make an educated guess I'd say we can expect Radeon8500
level performance which is still a good showing for a $100 DirectX
8.1 graphics card. I now simply hope Trident prove me wrong
and exceed this with clever drivers and optimal use of what
it now seems will be a tile based rendering engine.
Let's get the boring bit over and take a browse
over the specs as quoted by Trident ~
Mobile XP4 Specifications
Overview
Performance 3D graphics solution for low-power
notebooks
Scalable to mainstream and thin/light portables
CoolPower management (3.0 watts maximum dissipation)
Power supply: 1.2v, 1.5v, 2.5v, and 3.3v
30 million transistors in 0.13um CMOS process
Standard 612 BGA package (31mm x 31mm)
Performance
250 MHz graphics engine clock
Pixel fill rate: 1 billion pixels/sec (peak)
Texel processing rate: 8 billion texels/sec
Up to 666 MHz DDR memory clock
Up to 10.4 GBytes/sec memory bandwidth (peak)
SmartTileTM Memory Bus Architecture
128/64-bit Double Data Rate (DDR) memory at up
to 666 MHz
Up to 256 MBytes of local frame buffer with 16Mx16
memory
Supports 8Mx32, 4Mx32, 2Mx32, 16Mx16, 8Mx16, 4Mx16
Supports hierachical pixel tiling
Output Displays
Four simultaneous outputs: CRT, TFT, DVI and, TV
out
Dual-channel LVDS driver for interface to TFT
Single-channel TMDS driver for interface to DVI
with HDCP
420 MHz RAMDAC for interface to standard CRT
Digital interface to Trident's TVX2 NTSC/PAL encoder
CoolPowerTM Management
Unified software and hardware architecture for
power management
Dynamic clock gating, frequency scaling, work load
balancing
Supports Intel® defined Device Performance
States (DPS)
Optional battery optimizer under user control
DirectX 8.1
MICROSOFT® graphics standard for Windows®
XP
Fully programmable Vertex Shader and Pixel Shader
hardware
All DirectX 8.1 texture types (volume, projective,
bump maps, etc.)
Special low resolution, edge correction for better
image quality
|
BrightPixelTM Graphics
Engine
Up to 250MHz engine clock
Based on hierachical pixel tiling for rasterization
Four independent pixel pipelines (512-bit wide)
4 pixels/clock with 8 textures/pixel
Texture size up to 4K x 4K and non-power of 2
Bi-linear, tri-linear and anisotropic texture filtering
Full anti-aliasing support for texts, lines, scenes
Special hardware acceleration for silhouette anti-aliasing
Special multi-resolution depth buffer
Special bandwidth reduction hardware via compression
Multi-level caches
Fully OpenGL-compliant blending including fog &
depth cueing
Video Engine
State-of-the-art video de-interlacing (beyond Bob-and-Weave)
Supports HDTV resolution up to 1920 x 1080
TrueVideo® provides bilinear interpolation
with proprietary edge recovery scaling
Dual apertures for simultaneous access to graphics
and video display memory areas
DVD Support
Microsoft's DirectX Video Acceleration (DXVA)
Includes both Motion Compensation and IDCT hardware
Real-time playback (30 fps) of 9.8 Mbps and MPEG-2
video bitstream,
with 85% CPU headroom for other applications
Software
Windows® XP, 98, ME, 2000, NT 4.0, and 5.0
DirectX 7.0 and 8.1
DirectX Video Acceleration (DXVA)
DirectShow 3.0 and 4.0
OpenGL ICD 1.2 and 1.3
Linux
|
XP4 For Desktop
|
Memory
Clock
|
CPU
Clock
|
Fill
Rate
|
Memory
Bandwidth
|
XP4
- T1 |
Up
to 500 MHz (64 bit memory bus)
|
250
MHz
|
1
billion pixels/sec
|
Up
to 4.0 GBytes/sec
|
XP4
- T2 |
Up
to 500 MHz
|
250
MHz
|
1
billion pixels/sec (peak)
|
Up
to 8.0 GBytes/sec
|
XP4
- T3 |
Up
to 700 MHz
|
Up
to 300 MHz
|
1.2
billion pixels/sec (peak)
|
Up
to 11.2 GBytes/sec
|
XP4 T1 Specifications
Overview
Performance 3D graphics solution for mainstream
value desktop
64-bit DDR memory bus with up to 64 Mbytes frame
buffer
CoolPowerTM management (3.0 watts maximum dissipation)
Power supply: 1.2v, 1.5v, 2.5v, and 3.3v
30 million transistors in 0.13um CMOS process
Standard 612 BGA package (31mm x 31mm)
Performance
250 MHz graphics engine clock
Pixel fill rate: 1 billion pixels/sec (peak)
Texel processing rate: 8 billion texels/sec
Up to 500 MHz DDR memory clock
Up to 4.0 GBytes/sec memory bandwidth (peak)
SmartTileTM Memory Bus Architecture
64-bit Double Data Rate (DDR) memory at up to 500
MHz
Up to 64 Mbytes of local frame buffer
Supports 8Mx32, 4Mx32, 2Mx32, 8Mx16, 4Mx16
Supports hierachical pixel tiling
Output Displays
Three simultaneous outputs: CRT, DVI and TV out
Single-channel TMDS driver for interface to DVI
with HDCP
420 MHz RAMDAC for interface to standard CRT
Digital interface to Trident's TVX2 NTSC/PAL encoder
CoolPowerTM Management
Unified software & hardware architecture for
power management
Dynamic clock gating, frequency scaling, work load
balancing
Supports INTEL® defined Device Performance
States (DPS)
DirectX 8.1/9.0
MICROSOFT® graphics standard for Windows®
XP
Fully programmable Vertex and Pixel Shader hardware
All DirectX 8.1 texture types (volume, projective,
bump maps ...)
Special low-resolution edge correction for better
image quality
|
BrightPixelTM Graphics
Engine
Up to 250 MHz engine clock
Based on hierachical pixel tiling for rasterization
Four independent pixel pipelines (512-bit wide)
4 pixels/clock with 8 textures/pixel
Texture size up to 4Kx4K and non-power of 2
Bilinear, tri-linear and anisotropic texture filtering
Full anti-aliasing support for texts, lines, scenes
Special hardware acceleration for silhouette anti-aliasing
Special multi-resolution depth buffer
Special bandwidth reduction hardware via compression
Multilevel caches
Fully OpenGL-compliant blending including fog &
depth cueing
Video Engine
State-of-the-art video de-interlacing (beyond Bob-and-Weave)
Supports HDTV resolution up to 1920 x 1080
TrueVideo® provides bilinear interpolation
with proprietary
edge recovery scaling
Dual apertures for simultaneous access to graphics
and video
display memory areas
DVD Support
Microsoft's DirectX Video Acceleration (DXVA)
Includes both Motion Compensation and IDCT hardware
Real-time playback (30 fps) of 9.8 Mbps MPEG-2
video bitstream
with 75% CPU headroom for other applications
Software
Windows® XP, 98, ME, 2000, NT 4.0 and 5.0
DirectX 9.0, 8.1 and 7.0
DirectX Video Acceleration (DXVA)
DirectShow 3.0 and 4.0
OpenGL ICD 1.2 and 1.3
Linux
|
XP4 T2 Specifications
Overview
Performance 3D graphics solution for mainstream
desktop
128-bit DDR memory bus with up to 64 Mbytes frame
buffer
CoolPowerTM management (3.0 watts maximum dissipation)
Power supply: 1.2v, 1.5v, 2.5v, and 3.3v
30 million transistors in 0.13um CMOS process
Standard 612 BGA package (31mm x 31mm)
Performance
250 MHz graphics engine clock
Pixel fill rate: 1 billion pixels/sec (peak)
Texel processing rate: 8 billion texels/sec
Up to 500 MHz DDR memory clock
Up to 8.0 GBytes/sec memory bandwidth (peak)
SmartTileTM Memory Bus Architecture
128/64-bit Double Data Rate (DDR) memory at up
to 500 MHz
Up to 64 Mbytes of local frame buffer
Supports 8Mx32, 4Mx32, 2Mx32, 8Mx16, 4Mx16
Supports hierachical pixel tiling
Output Displays
Three simultaneous outputs: CRT, DVI and TV out
Single-channel TMDS driver for interface to DVI
with HDCP
420 MHz RAMDAC for interface to standard CRT
Digital interface to Trident's TVX2 NTSC/PAL encoder
CoolPowerTM Management
Unified software & hardware architecture for
power management
Dynamic clock gating, frequency scaling, work load
balancing
Supports INTEL® defined Device Performance
States (DPS)
DirectX 8.1/9.0
MICROSOFT® graphics standard for Windows®
XP
Fully programmable Vertex and Pixel Shader hardware
All DirectX 8.1 texture types (volume, projective,
bump maps ...)
Special low-resolution edge correction for better
image quality
|
BrightPixelTM Graphics Engine
Up to 250 MHz engine clock
Based on hierachical pixel tiling for rasterization
Four independent pixel pipelines (512-bit wide)
4 pixels/clock with 8 textures/pixel
Texture size up to 4Kx4K and non-power of 2
Bilinear, tri-linear and anisotropic texture filtering
Full anti-aliasing support for texts, lines, scenes
Special hardware acceleration for silhouette anti-aliasing
Special multi-resolution depth buffer
Special bandwidth reduction hardware via compression
Multilevel caches
Fully OpenGL-compliant blending including fog &
depth cueing
Video Engine
State-of-the-art video de-interlacing (beyond Bob-and-Weave)
Supports HDTV resolution up to 1920 x 1080
TrueVideo® provides bilinear interpolation
with proprietary
edge recovery scaling
Dual apertures for simultaneous access to graphics
and video
display memory areas
DVD Support
Microsoft's DirectX Video Acceleration (DXVA)
Includes both Motion Compensation and IDCT hardware
Real-time playback (30 fps) of 9.8 Mbps MPEG-2
video bitstream
with 85% CPU headroom for other applications
Software
Windows® XP, 98, ME, 2000, NT 4.0 and 5.0
DirectX 9.0, 8.1 and 7.0
DirectX Video Acceleration (DXVA)
DirectShow 3.0 and 4.0
OpenGL ICD 1.2 and 1.3
Linux
|
XP4 T3 Specifications
Overview
Performance 3D graphics solution for mainstream
high-end desktop
128-bit DDR memory bus with up to 256 Mbytes frame
buffer
CoolPowerTM management (4.0 watts maximum dissipation)
Power supply: 1.2v, 1.5v, 2.5v, and 3.3v
30 million transistors in 0.13um CMOS process
Standard 612 BGA package (31mm x 31mm)
Performance
Up to 300 MHz graphics engine clock
Pixel fill rate: 1.2 billion pixels/sec (peak)
Texel processing rate: 9.6 billion texels/sec
Up to 700 MHz DDR memory clock
Up to 11.2 GBytes/sec memory bandwidth (peak)
SmartTileTM Memory Bus Architecture
128/64-bit Double Data Rate (DDR) memory at up
to 700 MHz
Up to 256 Mbytes of local frame buffer
Supports 8Mx32, 4Mx32, 2Mx32, 16Mx16, 8Mx16, 4Mx16
Supports hierachical pixel tiling
Output Displays
Three simultaneous outputs: CRT, DVI and TV out
Single-channel TMDS driver for interface to DVI
with HDCP
420 MHz RAMDAC for interface to standard CRT
Digital interface to Trident's TVX2 NTSC/PAL encoder
CoolPowerTM Management
Unified software & hardware architecture for
power management
Dynamic clock gating, frequency scaling, work load
balancing
Supports INTEL® defined Device Performance
States (DPS)
DirectX 8.1/9.0
MICROSOFT® graphics standard for Windows®
XP
Fully programmable Vertex and Pixel Shader hardware
All DirectX 8.1 texture types (volume, projective,
bump maps ...)
Special low-resolution edge correction for better
image quality
|
BrightPixelTM Graphics Engine
Up to 300 MHz engine clock
Based on hierachical pixel tiling for rasterization
Four independent pixel pipelines (512-bit wide)
4 pixels/clock with 8 textures/pixel
Texture size up to 4Kx4K and non-power of 2
Bilinear, tri-linear and anisotropic texture filtering
Full anti-aliasing support for texts, lines, scenes
Special hardware acceleration for silhouette anti-aliasing
Special multi-resolution depth buffer
Special bandwidth reduction hardware via compression
Multilevel caches
Fully OpenGL-compliant blending including fog &
depth cueing
Video Engine
State-of-the-art video de-interlacing (beyond Bob-and-Weave)
Supports HDTV resolution up to 1920 x 1080
TrueVideo® provides bilinear interpolation
with proprietary edge recovery scaling
Dual apertures for simultaneous access to graphics
and video display memory areas
DVD Support
Microsoft's DirectX Video Acceleration (DXVA)
Includes both Motion Compensation and IDCT hardware
Real-time playback (30 fps) of 9.8 Mbps MPEG-2
video bitstream
with 85% CPU headroom for other applications
Software
Windows® XP, 98, ME, 2000, NT 4.0 and 5.0
DirectX 9.0, 8.1 and 7.0
DirectX Video Acceleration (DXVA)
DirectShow 3.0 and 4.0
OpenGL ICD 1.2 and 1.3
Linux
|
Unlike SiS it seems Trident have decided not to
opt for AGP 8x implementation preferring to stick with the tried
and tested 4x interface. With Trident claiming they're now on
a 6 month refresh cycle I really don't see this as being a problem
provided they can implement AGP 8x next year without too much
of a redesign. They've also decided to use a rather limiting
four rendering pipelines each capable of two textures in a single
pass and this fact alone is proof that Trident aren't gunning
to nudge off any performance crowns, not yet at least. It does
however give it a distinct theoretical advantage over ATi's
Radeon 9000. An interesting point is the quoted 11.2 GB/sec
memory bandwidth (peak) for the XP4 T3. This stacks up very
well against the NVIDIA Ti4600's 10.4GB/sec, on paper at least.
Maybe the biggest question is just how Trident
have managed to build a DirectX 8.1 part on a 30 million transistor
die and Trident's answer is that they've used some clever maths
and optimised algorithms to drastically boost the efficiency
of the four pipelines which by the way are non-uniform, each
being around half the size of the adjacent one running 15 million
transistors for the first, 7.5 million for the second, 3.8 million
for the third and 2 million for the fourth pipeline. Is this
marketing speak that translates as "we do in software what
others do in hardware"? No not necessarily but I'd be very
interested to know just what features are reliant solely on
drivers and which are actually hardware accelerated.
I also don't believe the XP4 features an independent
hardwired TCL unit, relying instead on its hardware Vertex and
Pixel Shaders to do the donkey work. If these are efficient
enough we shouldn't see too much of a problem with this assuming
the bandwidth is cleverly managed.
So what about the decision to use a tile based
rendering approach? Well, Kyro proved that it can be done and
it can be done well but those who may remember the PowerVR chipset
may also remember just how bad an idea this can be without very
specifically coded drivers. Tile based rendering is certainly
a great bandwidth saver and I don't think it's any secret that
both NVIDIA and ATi have heavily researched the area. Combine
this with other bandwidth trimming techniques such as vertex
caches, texture compression, Z-compression and occlusion culling,
all of which Trident say are implemented in their silicon, and
you can perhaps begin to see why they felt they could live with
using a rather conservative 128-bit memory bus (64 bit on the
T1).
According to Trident their FSAA will comprise
a variety of methods including super-sampling and multi-sampling
though precisely which is used when remains a mystery. There's
no mention of Anistropic filtering techniques so that's one
to save for the hardware reviews. We also understand that displacement
maps and shadows are supported in hardware along with hardware
acceleration for silhouette anti-aliasing.
Surely one of the big pluses for the XP4 will
be its frugal power requirements which stem directly from its
low transistor count. The T3 is quoted at only 4watts maximum
dissipation which is very impressive and presumably means the
card will likely ship with only passive cooling (heat sink and
no fan). Trident may have a very strong product for notebook
users if nothing else, but I'm sure SiS are saying the very
same thing about their Xabre GPU.
Here's a very rough and ready look at how the
XP4 compares to some of its combatants ~
|
Trident
XP4 T3
|
ATI
Radeon 8500
|
SiS
Xabre 400
|
GeForce4 Ti4600
|
Process |
0.13
micron
|
0.15
micron
|
0.15
micron
|
0.15
micron
|
Core
clock |
Up
to 300MHz
|
250MHz
|
250MHz
|
300MHz
|
Memory
clock speed. |
Up
to 350MHz
|
250MHz
|
250MHz
|
325MHz
|
Memory
Bus width |
128-bit
- DDR
|
128-bit
-DDR
|
64
/ 128-bit -DDR
|
128-bit
-DDR
|
Memory
Type |
Up
to 256MB DDR-SDRAM
|
128MB
DDR-SDRAM
|
Up
to 128MB DDR-SDRAM
|
128MB
DDR-SDRAM
|
Transistors |
30
million
|
60
million
|
?
|
63
million
|
Memory
Bandwidth. |
11.2GB/sec
(peak)
|
8.8GB/sec
|
8.0GB/sec
|
10.4GB/sec
|
Rendering
Pipelines. |
4
|
4
|
4
|
4
|
Texture
Units Per Pipeline. |
2
|
2
|
2
|
2
|
Theoretical
Fill Rate. |
1,200Mpixels/sec
|
1,100Mpixels/sec
|
.
|
1,200Mpixels/sec
|
AGP
|
4x
|
4x
|
4x/8x
|
4x
|
Conclusion :
So what can we expect for the XP4? Well with so
little information available it's hard to say but there's certainly
an opening at the budget end of the graphics market of a competent
DirectX 8.1 accelerator. Provided the XP4 lives up to its claims
I don't see either ATi's 9000 or NVIDIA's MX series offering
a serious threat in terms of the technology on offer. Where
the XP4 may loose out is to NVIDIA's Ti4200, SiS' Xabre400 and
ATi's Radeon 8500 (while it remains available). Not necessarily
because they're either faster or better, though they could very
well be both, but because they're known quantities with a head
start, mature or maturing drivers and a good marketing team.
Trident don't just need to demonstrate good performance, they
also need to provide solid drivers and quality support if they're
to gain the trust of a very fickle and increasingly knowledgeable
public. Can they do it? Come the end of October we can perhaps
begin to answer that question but until then you'll have to
watch for the usual assortment of leaked benchmarks and draw
your own conclusions.
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