Graphics Processing Unit: Difference between revisions

{{tropeUseful Notes}}

=== Console 2D GPU ===

=== Computer 2D GPU ===

The CPU effort is more involved in this case. Every element must be explicitly drawn by a CPU command. The background was generally the most complicated. This is why many early computer games used a static background. They basically had a single background image in video memory which they blitted to the framebuffer each frame, followed by a few sprites on top of it. Later PC games before the 3D era managed to equal or exceed the best contemporary consoles like the [[Super NES]] both through raw power (the 80486DX2/66, a common gaming processor of the early 90s, ran at 66 MHz, almost 10 times the clock speed of the [[Sega Genesis]], and could run 32-bit code as an "extension" to 16-bit DOS) and through various programming tricks that took advantage of quirks in the way early PCs and VGA worked. [[John Carmack]] once described the engine underpinning his company's breakout hit ''[[Wolfenstein 3D (Video Game)|Wolfenstein 3D]]'' as "a collection of hacks", and he was not too far off. (It was also the last of their games that could not only run, but was comfortably playable on an 80286 PC with 1 MB RAM -- a machine that was considered low-end even in 1992 -- which serves as a testament to the efficiency of some of those hacks.)

=== Basic 3D GPU ===

=== Modern 3D GPU ===

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{{quote| color {{=}} Write it Yourself!}}

=== Difference between GPU and CPU ===

=== The Future ===

GPUs today can execute a lot of programs that formerly only CPUs could, but with radically different performance characteristics. A typical home GPU can run hundreds of threads at once, while a typical mid-range home CPU can run two to4-16 fourthreads. On the other hand, each GPU thread progresses far more slowly than a CPU thread. Thus if you have thousands of almost identical tasks you need to run at once, like many pixels in a graphical scene or many objects in a game with physics, a GPU might be able to do work a hundred times faster than a CPU. But if you only have a few things to do and they have to happen in sequence, a CPU-style architecture will give vastly better performance. As general-purpose GPU programming progresses, GPUs might get used for more and more things until they're nearly as indispensable as CPUs. (OrIndeed, in some tasks a strong GPU is often required: From the late 2010s on, more and more consumer devices include powerful GPUs for things other than gaming, often related to maybemachine notlearning.)

=== Some notable GPUs over the years: ===

=== 1970s ===

=== 1980s ===

=== 1990s ===

Developed for the [[Nintendo 64]], what this GPU brought was [http://en.[wikipedia.org/wiki/Spatial_anti:Spatial anti-aliasing |anti-aliasing]] and trilinear mipmapping (which helped textures look less pixelated up close). Mipmapping wasn't a standard feature for PCs until 1998, and anti-aliasing didn't show up until 2000, though impractical until 2002.

=== 2000s ===

This was the GPU for the [[Nintendo GamecubeGameCube]], and was superficially similar to the GeForce 2 and the original Radeon. Where it stood out was that it integrated a megabyte of RAM into the actual graphics processor itself, making it possible to carry out low levels of Anti-Aliasing with virtually zero performance loss. The Flipper itself was recycled and slightly upgraded to serve in the GameCube's successor, the [[Wii]].

What was actually stunning about this graphics card was that it supported the new [[Direct X]] 9.0 ''before it was officially released.'' But not only that, due to nVidia making a critical error (see below), it was a [[Curb Stomp Battle]] against the GeForce FX in any game using [[Direct X]] 9 (in particular, ''[[Half-Life 2 (Video Game)|Half-Life 2]]''). Moreover, it still offered exceptional performance in older games, thanks to ATi ditching the until-then popular multitexture designs in favor of a large array of single-texturing processors, which generally offered better performance and remains the standard approach for GPUs to this day. Sweetening the deal was a much more competent execution of the 256-bit memory bus that Matrox had attempted with the Parhelia, finally making Anti-Aliasing a commonly used feature. This cemented ATi as competitor in graphics processors. A slightly revised version, the Radeon 9800 was released the following year, and ATi also started selling their graphics chips to third-party board makers, ending nVidia's monopoly on that front.

After an unimpressive launch with the overheating, under-performing FX 5800 model, the succeeding FX 5900 was on par with ATi's cards in DirectX 7 and 8 games, but nVidia made some ill-advised decisions in implementing the shader processor across the series. Direct3D 9 required a minimum of 24-bit accuracy in computations, but nVidia's design was optimized around 16-bit math. It could do 32-bit, but only at ''half'' performance. nVidia had assumed that developers would write code specifically for their software. They didn't, and it resulted in the card performing barely half as well as the competing Radeons in ''[[Half-Life 2 (Video Game)|Half-Life 2]]'' and ''[[Far Cry]]''.

In 2008, Intel announced they would try their hands in the dedicated graphics market once more with a radical approach. Traditionally lighting is actually estimated using shading techniques done on each pixel. Intel's approach was to use [http://en.[wikipedia.org/wiki/Ray_tracing_%28graphics%29:Ray tracing (graphics)|ray tracing]], which at the time was a hugely computationally expensive operation. Intel's design however was to use the Pentium architecture, but scale it down using modern integrated chip sizes, modify it for graphic related instructions. A special version of ''[[Enemy Territory: Quake Wars (Video Game)|Enemy Territory Quake Wars]]'' was used to demonstrate it. It was axed in late 2009.

nVidia tried their hands on "real time" ray tracing with the GeForce GTX 480 using a proprietary API. However nVidia's attempts would not see adoption until 2018 with the release of the GeForce 20 series, introducing RTX hardware accelerated ray tracing.

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