GZeasy上Cho对于GS在填充纹理的时候的填充率下降一半的原因持有不同的观点--尽管GS内部有16条渲染管线但是只有8条能够贴图。他是这样说的。类似的情况还有“永远神秘”的Bitboys的Glaze3D:当时的指标是:150MHZ的核心频率,内置4条象素管线,每一条渲染管线中有2个纹理贴图单元。因此可以单周期渲染600MP的单纹理象素,在填充双纹理的象素的时候,这个值就是1200MP。以下就是最初的Glaze3D的规格:
Glaze3D 1200/2400(2400由两枚Glaze3D芯片构成)
1200/2400 MTEX/s
600/1200 MPIX/s Gouraud shaded, no texture
600/1200 MPIX/s single texture, trilinear mip-mapping
600/1200 MPIX/s dual texture, bilinear filtering
300/600 MPIX/s dual texture, trilinear mip-mapping
300/600 MPIX/s quad texture, bilinear filtering
300/600 MPIX/s environment bump mapping
150/300 MPIX/s quad texture, trilinear mipmapping
15M triangles/s
150MHz core speed
1.5M gate core
0.20 micron 嵌入式eDRAM
128MB 外部内存(最大)
64 or 128-bit 外部内存总线
143/166/200MHz 外部内存传输速度
AGP 2x/4x
AGP 带宽 532 MB/s(2x)/1064MB/s(4x)
最高分辨率为:2048 x 1536
32-bit color
quad-pixel 渲染管线(rendering pipeline )
完全硬件的多边形设定,微代码可编程浮点处理器
Full OpenGL anti-aliasing and edge-anti-aliasing for points, lines and triangles
Full-screen sort-independent anti-aliasing (full hardware support)
Flat color 或者 perspective correct Gouraud shading
Perspective correct per pixel exponential and linear no-cost fog
Separate per pixel perspective corrected diffuse and specular color supported at no additional cost
16/24/32-bit Z-buffer
8 bit stencil buffer
积聚缓冲(Accumulation buffer)
支持1, 2 or 4个Glaze3D渲染引擎并行运作
4 independent simultaneous textures with trilinear filtering in a single pass
4096 x 4096 pixel maximum texture size
DirectX texture compression (DXT) supported (4:1 ratio)
Point sample, high-quality bilinear, trilinear MIP mapping. Free filter selection for each texture when
rendering with multiple textures
2-tap and 4-tap 各项异性纹理过滤
浮雕方式的凹凸纹理映射和环境凹凸纹理映射
还有一大堆在很吸引的特性比如:4路的SLI(就是四块芯片并行操作,理论上新能能提高为单芯片的4倍)), 4096x4096高分辨率纹理等等。
分辨率 颜色深度 eDRAM 带宽 外部带宽
640x480 32 1 GB/s -
800x600 32 1.6 GB/s -
1024x768 32 2.6 GB/s -
1280x1024 32 2.9 GB/s 1.5 GB/s
1600x1200 32 4.2 GB/s 2.1 GB/s
2048x1536 16 3.5 GB/s 1.8 GB/s
1200芯片采用9MB的EDRAM,2400芯片采用18MB的EDRAM,带宽都是9.6GB每秒。
这一切看起来是多么的美好,可惜永远都是一个美丽的肥皂泡。
[此贴子已经被作者于2004-5-2 11:22:52编辑过] |