|
2#
楼主 |
发表于 6.1.2008 17:37:15
|
只看该作者
<span style="font-weight: bold;">PS3和Xbox360机能深度对比分析<br></span><font class="f14" id="zoom">中文独家首发:XBOX-360.cn</font>
<p><font class="f14" id="zoom"> (时间比较仓促,涉及硬件专业领域的术语如有误译,请各位包涵、指正!)</font></p>
<p><font class="f14" id="zoom"> 中央处理器CPU</font></p>
<p><font class="f14" id="zoom"> Cell (1个PowerPC核心 + 7个以 3.2 GHz 频率运作的协同处理器) |X360 Cpu (3个PowerPC核心)</font></p>
<p><font class="f14" id="zoom"> X360核心的优势和不足</font></p>
<p><font class="f14" id="zoom"> - 为三个同步核心编程要比对一个处理器编程容易许多</font></p>
<p><font class="f14" id="zoom"> - 强劲的单线程表现,但只能运行在受限制的线程数下</font></p>
<p><font class="f14" id="zoom"> - 多线程编程比较困难,但远远没有为Cell编程困难</font></p>
<p><font class="f14" id="zoom"> - 最好的概括就是:是个“条条大路通罗马”的解决方案。</font></p>
<p><font class="f14" id="zoom"> Cell核心的优势和不足</font></p>
<p><font class="f14" id="zoom"> - Cell是一颗强劲的平行向量处理器</font></p>
<p><font class="f14" id="zoom"> - 在运行多重浮点运算任务时表现出色(如游戏引擎、视频编码解码等)</font></p>
<p><font class="f14" id="zoom"> - 编程困难——所有的软件必须做特别优化</font></p>
<p><font class="f14" id="zoom"> - 单线程表现糟糕</font></p>
<p><font class="f14" id="zoom"> - 没有硬件的分支预警结构,在运行复杂的分支运算时表现尤其糟糕(如人工智能代码)</font></p>
<p><font class="f14" id="zoom"> - 高度专业化的解决方案,Cell是第一颗也是最重要的一颗多媒体处理器,非常适合HDTV和游戏主机的应用。是个两极分化的核心——在运行游戏引擎方面非常强;但在人工智能编码方面非常弱。</font></p>
<p><font class="f14" id="zoom"> 显示核心GPU</font></p>
<p><font class="f14" id="zoom"> 参考:今天最高端的6800ultra级显示核心拥有16条像素渲染管线,和6条阴影渲染管线,总共222百万个晶体管。</font></p>
<p><font class="f14" id="zoom"> X360的优势和不足</font></p>
<p><font class="f14" id="zoom"> - ATI的下一代GPU (即R500) 拥有独特的架构——统一的顶点、阴影和像素渲染引擎。拥有48条统一的引擎,会自动分配具体的功能。</font></p>
<p><font class="f14" id="zoom"> - 更容易编程,不过理论上峰值较独立的渲染管线有所降低。</font></p>
<p><font class="f14" id="zoom"> - 10MB的帧缓冲,允许“自由的”反锯齿效果,但限定在720p的分辨率上。</font></p>
<p><font class="f14" id="zoom"> - 晶体管数量未知</font></p>
<p><font class="f14" id="zoom"> PS3 GPU的优势和不足</font></p>
<p><font class="f14" id="zoom"> -
官方声称拥有300百万个晶体管,和改进的像素和顶点渲染管线。具体数目未知。从6600GT的160白万个晶体管到6800ultra的222百万个
——可以推测,PS3的GPU拥有24条像素渲染管线和大约10~12条阴影渲染管道。有理由相信PS3的GPU将两倍强大于6800Ultra的能力。</font></p>
<p><font class="f14" id="zoom"> - 独立的渲染管线运行更快但难以编程。</font></p>
<p><font class="f14" id="zoom"> 内存Memory</font></p>
<p><font class="f14" id="zoom"> X360</font></p>
<p><font class="f14" id="zoom"> 512MB统一的DDR3内存,GPU和CPU共享。 灵活性是其显著的优势。缺点是两者不得不共享。游戏开发者可以按照爱好自由地分配,如五五开或三七开等等。</font></p>
<p><font class="f14" id="zoom"> PS3</font></p>
<p><font class="f14" id="zoom"> Cell有256MB XRD</font></p>
<p><font class="f14" id="zoom"> GPU有256MB DDR3</font></p>
<p><font class="f14" id="zoom"> 优势在于每个核心都有独立的内存,速度更快,但都限制在256MB。而X360最大可以达到512MB,但Cell只能止步于256MB。</font></p>
<p><font class="f14" id="zoom"> 带宽Bandwidth</font></p>
<p><font class="f14" id="zoom"> X360</font></p>
<p><font class="f14" id="zoom"> • 22.4 GB/s 内存界面带宽</font></p>
<p><font class="f14" id="zoom"> • 256 GB/s EDRAM 内存带宽</font></p>
<p><font class="f14" id="zoom"> • 21.6 GB/s 前端总线</font></p>
<p><font class="f14" id="zoom"> 10MB的帧缓冲,256GB/s的带宽是X360GPU的主要优势;这意味着R500不会被带宽所限制,允许自由的反锯齿和其他影像特效。但代价就是写实般的画面只能限定在720p。再向上只能减帧</font></p>
<p><font class="f14" id="zoom"> 开发者应该有变通的办法。就像原来的PS2限制在4MB帧缓冲上;而NGC则只有2MB帧缓冲。</font></p>
<p><font class="f14" id="zoom"> PS3</font></p>
<p><font class="f14" id="zoom"> 主内存 25.6GB/s</font></p>
<p><font class="f14" id="zoom"> VRAM 22.4GB/s</font></p>
<p><font class="f14" id="zoom"> RSX 20GB/s (写) + 15GB/s (读)</font></p>
<p><font class="f14" id="zoom"> SB< 2.5GB/s (写) + 2.5GB/s (读)</font></p>
<p><font class="f14" id="zoom"> 相当标准。</font></p>
<p><font class="f14" id="zoom"> 视频输出Video Output</font></p>
<p><font class="f14" id="zoom"> X360</font></p>
<p><font class="f14" id="zoom"> 一个DVI输出端口,支持所有的HD(高清晰)分辨率(包括1080p和1080i)。注意大部分游戏很可能都运行于720p下,减帧运行于1080p下。就像GT4在PS2上那样。</font></p>
<p><font class="f14" id="zoom"> PS3</font></p>
<p><font class="f14" id="zoom"> 两个HDMI端口 (写保护DVI、音频联合接口) ,因此可以连接两台HDTV。HDMI是个全新的接口。</font></p>
<p><font class="f14" id="zoom"> 但是,如果你真的想这么做,那么不得不让同一款游戏在1080p下运行于一台电视上,另一台电视的分辨率只能达到720p。</font></p>
<p><font class="f14" id="zoom"> 其他的都是浮云……The rest are extras</font></p>
<p><font class="f14" id="zoom"> 以下所有的功能只会增加成本,对游戏本身的提升毫无帮助。PS3这方面显得尤其臃肿:</font></p>
<p><font class="f14" id="zoom"> 两个以太网接口</font></p>
<p><font class="f14" id="zoom"> 内建Wi-Fi</font></p>
<p><font class="f14" id="zoom"> 蓝牙</font></p>
<p><font class="f14" id="zoom"> 多种闪存接口(SD、记忆棒等)</font></p>
<p><font class="f14" id="zoom"> 蓝光光驱</font></p>
<p><font class="f14" id="zoom"> 以上PS3增加的功能,全部加起来要有100美刀。</font></p>
<p><font class="f14" id="zoom"> 结论</font></p>
<p><font class="f14" id="zoom"> X360和PS3的机能在同一水平上,只是在设计思想上的解决方案不同。</font></p>
<p><font class="f14" id="zoom"> X360机能烧弱,但更加灵活,易于编程;PS3理论上更为强劲,但灵活性不佳,也难以编程。</font></p>
<p><font class="f14" id="zoom"> 原文如下:</font></p>
<p><font class="f14" id="zoom"> 引用:</font></p>
<p><font class="f14" id="zoom"> ----------------------------------------------------------------</font></p>
<p><font class="f14" id="zoom"> CPU: Cell (1 PPC + 7 units) vs X360 Cpu (three PPC cores)</font></p>
<p><font class="f14" id="zoom"> X360 advantages and disadvantages</font></p>
<p><font class="f14" id="zoom"> - much easier to program for 3 symmetric processors than an asymmetric processor</font></p>
<p><font class="f14" id="zoom"> - strong single thread performance, but can only run limited number of threads</font></p>
<p><font class="f14" id="zoom"> - multithreading is difficult to program for but NO WAY near as hard as for the cell</font></p>
<p><font class="f14" id="zoom"> - Best described as a jack of all trades approach</font></p>
<p><font class="f14" id="zoom"> Cell Advantages and disadvantages</font></p>
<p><font class="f14" id="zoom"> - The cell is a massively parallel vector processor</font></p>
<p><font class="f14" id="zoom"> - excellent for running multiple floating point tasks such as (game engine, encoding and decoding video)</font></p>
<p><font class="f14" id="zoom"> - Difficult to program for -- ALL software has to be optimized</font></p>
<p><font class="f14" id="zoom"> - Poor single thread performance</font></p>
<p><font class="f14" id="zoom"> - NO hardware Branch prediction, Extremely poor at running complicated branched code (like A.I. code)</font></p>
<p><font class="f14" id="zoom"> - Highly specialized approach, the
cell is first and foremost an MULTIMEDIA processor that is best suited
for HDTVs and a gaming consoles processor second. It offers extremes --
very good at running game engine, very poor at A.I. code.</font></p>
<p><font class="f14" id="zoom"> GPU:</font></p>
<p><font class="f14" id="zoom"> Today's top of the line 6800ultra has 16 pixel pipelines and 6 shader pipelines and is made up of 222 Million Transistors</font></p>
<p><font class="f14" id="zoom"> X360 advantages and disadvantages</font></p>
<p><font class="f14" id="zoom"> - ATI's next gen GPU (the R500) has a
as unique architecture -- UNIFIED vertex/shader and pixel pipelines. It
has 48 of these units that are automatically assigned a function</font></p>
<p><font class="f14" id="zoom"> - Easier to program for but has a less higher theoretical peek than independet pipelines</font></p>
<p><font class="f14" id="zoom"> - 10MB framebuffer that allows for "Free" anti-aliasing but limited resolution to 720P. For higher resolutions you "upsample"</font></p>
<p><font class="f14" id="zoom"> - Unknown number of transistors (look for this number in the future)</font></p>
<p><font class="f14" id="zoom"> PS3 GPU:</font></p>
<p><font class="f14" id="zoom"> - officially stated to have 300
Million transistors with fixed pixel and vertex pipelines. Numbers not
disclosed. If 6600GT is about 160 Million transistors, the 6800ultra
222 Million -- it is very likely that the PS3 GPU has 24 pixel
pipelines and about 10-12 shader pipelines. I find it very easy to
believe that the this GPU will be about twice as powerful as a 6800Ultra</font></p>
<p><font class="f14" id="zoom"> - independent pipelines are faster BUT are harder to program for</font></p>
<p><font class="f14" id="zoom"> Memory:</font></p>
<p><font class="f14" id="zoom"> X360</font></p>
<p><font class="f14" id="zoom"> 512Mb of unified DDR3 memory with is
shared by BOTH the GPU and CPU. Flexiablity is the obvious advantage.
Disadvantage is that they have to be shared. Game developers can split
the memory any way they like 50:50, 30:70 etc</font></p>
<p><font class="f14" id="zoom"> PS3</font></p>
<p><font class="f14" id="zoom"> 256MB XRD for the cell</font></p>
<p><font class="f14" id="zoom"> 256MB DDR3 for the GPU</font></p>
<p><font class="f14" id="zoom"> advantage is that the each has its own
faster memory but each is limited to 256mb. While the CPU in the X360
can have a max of 512mb, the cell is stuck with 256mb.</font></p>
<p><font class="f14" id="zoom"> Bandwidth:</font></p>
<p><font class="f14" id="zoom"> X360</font></p>
<p><font class="f14" id="zoom"> • 22.4 GB/s memory interface bus bandwidth</font></p>
<p><font class="f14" id="zoom"> • 256 GB/s memory bandwidth to EDRAM</font></p>
<p><font class="f14" id="zoom"> • 21.6 GB/s front-side bus</font></p>
<p><font class="f14" id="zoom"> 256GB/s from the 10mb frame buffer
gives the X360 GPU a major advantage; it means the R500 isn’t limited
by bandwidth and allows for free Antialiasing and a host of other
effects. But the cost is that internal resolution is realistically
limited to 720P. They may find a way around it. The original PS2 had
on-die 4mb frame buffer. The game cube had off-die 2mb frame buffer.</font></p>
<p><font class="f14" id="zoom"> PS3</font></p>
<p><font class="f14" id="zoom"> Main RAM 25.6GB/s</font></p>
<p><font class="f14" id="zoom"> VRAM 22.4GB/s</font></p>
<p><font class="f14" id="zoom"> RSX 20GB/s (write) + 15GB/s (read)</font></p>
<p><font class="f14" id="zoom"> SB< 2.5GB/s (write) + 2.5GB/s (read)</font></p>
<p><font class="f14" id="zoom"> Pretty standard.</font></p>
<p><font class="f14" id="zoom"> Video Output:</font></p>
<p><font class="f14" id="zoom"> X360</font></p>
<p><font class="f14" id="zoom"> Single DVI-output support sall HD
resolutions (including 1080P and 1080i). Note that most games will
probably be rendered at 720P but upsampled to 1080P like GT4 did with
the PS2.</font></p>
<p><font class="f14" id="zoom"> PS3</font></p>
<p><font class="f14" id="zoom"> Dual HDMI (copy-protected DVI that combines audio) so that you can hook up two HDTVs. HDMI is a new format.</font></p>
<p><font class="f14" id="zoom"> BUT for those of you who tried doing
this on your computer, if a game runs @ 1080P single TV, you have to
drop the resolution down on each TV to 720P so that you can have both.</font></p>
<p><font class="f14" id="zoom"> The rest are extras</font></p>
<p><font class="f14" id="zoom"> That only increase costs and don’t make gamming any better. PS3 has a lot of fat</font></p>
<p><font class="f14" id="zoom"> Dual eithernet</font></p>
<p><font class="f14" id="zoom"> Built-in wi-fi</font></p>
<p><font class="f14" id="zoom"> Bluetooth</font></p>
<p><font class="f14" id="zoom"> Multi-types of flash memory slots (SD, memory stick etc)</font></p>
<p><font class="f14" id="zoom"> blueray</font></p>
<p><font class="f14" id="zoom"> The above probably adds $100 extra to PS3</font></p>
<p><font class="f14" id="zoom"> Conclusion</font></p>
<p><font class="f14" id="zoom"> X360 and PS3 are about the same in
power but approach it with different philosophy. X360 is less powerful
BUT more flexible and easier to program for. PS3 is theoretically more
powerful but less flexible and harder to program.</font></p><br> |
|