Editing RSX

= Hardware =

<div style="float:right">[[File:SCEI CXD2971DGB.JPG|200px|thumb|left|<br />RSX - Reality Synthesizer<br />1st generation 90nm<br />CXD2971DGB]]<br />[[File:RSX-GDDR-BGA-lifted.jpg|200px|thumb|left|<br />RSX - Reality Synthesizer<br />GDDR3 BGA lifted]]<br />[[File:RSX-GPUcore-lifted.jpg|200px|thumb|left|<br />RSX - Reality Synthesizer<br />GPUcore BGA lifted]]<br />[[File:RSX-BGA-lifted-missingpads.jpg|200px|thumb|left|<br />RSX - Reality Synthesizer<br />BGA lifted<br />PCB underneath]]</div>

RSX - Reality Synthesizer

The RSX 'Reality Synthesizer' is a proprietary graphics processing unit (GPU) codeveloped by Nvidia and Sony for the PlayStation 3 game console. It is a GPU based on the Nvidia 7800GTX graphics processor and, according to Nvidia, is a G70/G71 (previously known as NV47) hybrid architecture with some modifications. The RSX has separate vertex and pixel shader pipelines. The GPU makes use of 256 MB GDDR3 RAM clocked at 650 MHz with an effective transmission rate of 1.4 GHz and up to 224 MB of the 3.2 GHz XDR main memory via the CPU (480 MB max).

== Specifications ==
* 500&nbsp;MHz on 90 nm process (shrunk to 65 nm in 2008 and to 40 nm in 2010)
* Based on NV47 Chip (Nvidia GeForce 7800 Architecture)
* Little Endian
** 300+ million transistors
** Multi-way programmable parallel floating-point shader pipelines
*** Independent pixel/vertex shader architecture
*** 24 parallel pixel-shader ALU pipes clocked @ 550 MHz
**** 5 ALU operations per pipeline, per cycle (2 vector<sub>4</sub> , 2 scalar/dual/co-issue and fog ALU, 1 Texture ALU)
**** 27 floating-point operations per pipeline, per cycle
*** 8 parallel vertex pipelines
**** 2 ALU operations per pipeline, per cycle (1 vector<sub>4</sub> and 1 scalar, dual issue)
**** 10 FLOPS per pipeline, per cycle
*** Floating Point Operations: 400.4 Gigaflops ((24 * 27 Flops + 8 * 10 Flops) * 550)
** 24 texture filtering units (TF) and 8 vertex texture addressing units (TA)
*** 24 filtered samples per clock
**** Maximum Texel fillrate: 12.0  GigaTexels per second (24 textures * 500&nbsp;MHz)
*** 32 unfiltered texture samples per clock, ( 8 TA x 4 texture samples )
** 8 Render Output units / pixel rendering pipelines
*** Peak pixel fillrate (theoretical): 4.0 Gigapixel per second
*** Maximum Z-buffering sample rate: 8.0 GigaSamples per second (2 Z-samples * 8 ROPs * 500&nbsp;MHz)
** Maximum Dot product operations: 51 billion per second (combined with Cell CPU)
** 128-bit pixel precision offers rendering of scenes with High dynamic range rendering
** 256 MB GDDR3 RAM at 650&nbsp;MHz
*** Earlier PS3 Models: Samsung K4J52324QC-SC14 rated at 700Mhz
*** Later PS3 Models: Qimonda HYB18H512322AF-14
*** 128-bit memory bus width
*** 22.4 GB/s read and write bandwidth
** Cell FlexIO bus interface
*** Rambus XDR Memory interface bus width: 56bit out of 64bit (serial)
*** 20 GB/s read to the Cell and XDR memory
*** 15 GB/s write to the Cell and XDR memory
** Support for PSGL (OpenGL ES 1.1 + Nvidia Cg)
** Support for S3 Texture Compression



More features are revealed in the following chart delineating the differences between the RSX and the nVidia 7800 GTX.

{|class="wikitable"
|-
! Difference !! RSX !! nVidia 7800GTX
|-
| GDDR3 Memory bus || 128bit || 256bit
|-
| ROPs || 8 || 16
|-
| Post Transform and Lighting Cache || 63 max vertices || 45 max vertices
|-
| Total Texture Cache Per Quad of Pixel Pipes (L1 and L2) || 96kB || 48kB
|-
| CPU interface || FlexIO || PCI-Express 16x
|-
| Technology || 40nm/65nm/90nm || 110nm
|-
|}

Other RSX features/differences include:

    More shader instructions
        Extra texture lookup logic (helps RSX transport data from XDR)
        Fast vector normalize 

Note that the cache (Post Transform and Lighting Vertext Cache) is located between the vector shader and the triangle setup.

A sample flow of data inside the RSX would see them first processed by 8 vertex shaders. The output are then sent to the 24 active pixel shaders, which can involve the 24 active texture units. Finally, the data is passed to the 8 Raster Operation Pipeline units (ROPs), and on out to the GDDR3. Note that the pixel shaders are grouped into groups of four (called Quads). There are 7 Quads, with 1 redundant, leaving 6 Quads active, which provides us with the 24 active pixel shaders listed above (6 times 4 equals 24). Since each Quad has 96kB of L1 and L2 cache, the total RSX texture cache is 576kB. General RSX features include 2x and 4x hardware anti-aliasing, and support for Shader Model 3.0.


== RSX Memorymap ==

Although the RSX has 256MB of GDDR3 RAM, not all of it is useable. The last 4MB is reserved for keeping track of the RSX internal state and issued commands. The 4MB of GPU Data contains RAMIN, RAMHT, RAMFC, DMA Objects, Graphic Objects, and the Graphic Context. The following is a breakdown of the address within 256MB of the RSX.

{|class="wikitable"
|-
! Address Range !! Size !! Comment
|-
| 0000000-FBFFFFF || 252 MB || Framebuffer
|-
| FC00000-FFFFFFF || 4 MB || GPU Data
|-
| FF80000-FFFFFFF || 512KB || RAMIN: Instance Memory
|-
| FF90000-FF93FFF || 16KB || RAMHT: Hash Table
|-
| FFA0000-FFA0FFF || 4KB/s || RAMFC: FIFO Context
|-
| FFC0000-FFCFFFF || 64KB || DMA Objects
|-
| FFD0000-FFDFFFF || 64KB || Graphic Objects
|-
| FFE0000-FFFFFFF || 128KB || GRAPH: Graphic Context
|-
|}

== Chipnumers @ SKU's ==
The following is a small sample of serial numbers of the RSX by model number.

{|class="wikitable"
|-
! PS3 Model !! Mobo serial !! RSX Serial !! Die Tech !! Die Size !! Remark
|-
| CECHA || -  || CXD2971GB || 90nm || 258mm² || [http://www.edepot.com/playstation3.html#PS3_RSX_GPU edepot ps3secrets]
|-
| CECHA || 1-871-868-12 || CXD2971AGB || 90nm || 258mm² || [http://reballing.es/viewtopic.php?f=13&t=2131 reballing.es]
|-
| CECHA || 1-871-868-22 || CXD2971DGB || 90nm || 258mm² || [http://reballing.es/viewtopic.php?f=13&t=2131 reballing.es]
|-
| CECHA || 1-871-868-32 || CXD2971DGB || 90nm || 258mm² || [http://reballing.es/viewtopic.php?f=13&t=2131 reballing.es]
|-
| CECHA || 1-871-868-32 || CXD2971AGB || 90nm || 258mm² || [http://reballing.es/viewtopic.php?f=13&t=2131 reballing.es]
|-
| CECHB || 1-871-868-22  || CXD2971DGB || 90nm || 258mm² || [http://www.edepot.com/playstation3.html#PS3_RSX_GPU edepot ps3secrets]
|-
| CECHB || 1-871-868-32  || CXD2971DGB || 90nm || 258mm² || [http://www.edepot.com/playstation3.html#PS3_RSX_GPU edepot ps3secrets]
|-
| CECHC || -  || CXD2971DGB || 90nm || 258mm² || [http://www.edepot.com/playstation3.html#PS3_RSX_GPU edepot ps3secrets]
|-
| CECHC || 1-873-513-21 || CXD2971GB || 90nm || 258mm² || [http://reballing.es/viewtopic.php?f=13&t=2131 reballing.es]
|-
| CECHC || 1-873-513-31 || CXD2971DGB || 90nm || 258mm² || [http://reballing.es/viewtopic.php?f=13&t=2131 reballing.es]
|-
| CECHD || unreleased || - || 90nm || 258mm² || -
|-
| CECHE || -? || -? || 90nm || 258mm² || -
|-
| CECHF || unreleased || - || 90nm || 258mm² || -
|-
| CECHG || 1-875-384-11 || CXD2971DGB || 90nm || 258mm² || [http://reballing.es/viewtopic.php?f=13&t=2131 reballing.es]
|-
| CECHG || 1-875-384-31 || CXD2971DGB || 90nm || 258mm² || [http://reballing.es/viewtopic.php?f=13&t=2131 reballing.es]
|-
| CECHG || 1-875-384-21 || CXD2971AGB || 90nm || 258mm² || [http://reballing.es/viewtopic.php?f=13&t=2131 reballing.es]
|-
| CECHG || -  || CXD2971DGB || 90nm || 258mm² || [http://www.edepot.com/playstation3.html#PS3_RSX_GPU edepot ps3secrets]
|-
| CECHH || 1-875-938-11 || CXD2971AGB || 90nm || 258mm² || [http://reballing.es/viewtopic.php?f=13&t=2131 reballing.es]
|-
| CECHH || 1-875-938-31 || CXD2971-1GB || 90nm || 258mm² || [http://reballing.es/viewtopic.php?f=13&t=2131 reballing.es]
|-
| CECHH || 1-875-938-31 || CXD2971AGB || 90nm || 258mm² || [http://reballing.es/viewtopic.php?f=13&t=2131 reballing.es]
|-
| CECHH || -  || CXD2971AGB || 90nm || 258mm² || [http://www.edepot.com/playstation3.html#PS3_RSX_GPU edepot ps3secrets]
|-
| CECHI || unreleased || - || 90nm || 258mm² || -
|-
| CECHJ || -? || -? || 65nm || ? 186mm² ? || -
|-
| CECHK || 1-876-912-42 || CXD2982GB || 65nm || ? 186mm² ? || [http://reballing.es/viewtopic.php?f=13&t=2131 reballing.es]
|-
| CECHK || -  || CXD2982GB || 65nm || ? 186mm² ? || [http://www.edepot.com/playstation3.html#PS3_RSX_GPU edepot ps3secrets]
|-
| CECHL || 1-878-196-31 || CXD2991GB || 65nm || ? 186mm² ? || [http://reballing.es/viewtopic.php?f=13&t=2131 reballing.es]
|-
| CECHL || -  || CXD2991GB || 65nm || ? 186mm² ? || [http://www.edepot.com/playstation3.html#PS3_RSX_GPU edepot ps3secrets]
|-
| CECHM || -?  || -? || 65nm || ? 186mm² ? || -
|-
| CECHN || unreleased || - || 65nm || ? 186mm² ? || -
|-
| CECHO || unreleased || - || 65nm || ? 186mm² ? || -
|-
| CECHP || -?  || -? || 65nm || ? 186mm² ? || -
|-
| CECHQ || -?  || -? || 65nm || ? 186mm² ? || -
|-
| CECH-2001A || -  || CXD2991CGB || 65nm || ? 186mm² ? || [http://reballing.es/viewtopic.php?f=13&t=2131 reballing.es]
|-
| CECH-2001B || 1-880-055-31 || CXD2991EGB || 65nm || ? 186mm² ? || [http://reballing.es/viewtopic.php?f=13&t=2131 reballing.es]
|-
| CECH-20xx || -  || CXD2991EGB || 65nm || ? 186mm² ? || [http://www.edepot.com/playstation3.html#PS3_RSX_GPU edepot ps3secrets]
|-
| CECH-2101A || 1-881-945-11 || CXD5300AGB || 40nm || ? 114mm² ? || [http://reballing.es/viewtopic.php?f=13&t=2131 reballing.es]
|-
| CECH-21xx || -  || CXD5300AGB || 40nm || ? 114mm² ? || [http://www.edepot.com/playstation3.html#PS3_RSX_GPU edepot ps3secrets]
|-
| CECH-25xx || -  || CXD5300A1GB || 40nm || ? 114mm² ? || [http://www.edepot.com/playstation3.html#PS3_RSX_GPU edepot ps3secrets]
|-
| CECH-30xx || -?  || -? || ? 40nm ? || ? 114mm² ? || -
|-
|}

Other unspecified: CXD297BGB

==Speed, Bandwidth, and Latency==
Because of the aforementioned layout of the communication path between the different chips, and the latency and bandwidth differences between the various components, there are different access speeds depending on the direction of the access in relation to the source and destination. The following is a chart showing the speed of reads and writes to the GDDR3 and XDR memory from the viewpoint of the Cell and RSX. Note that these are measured speeds (rather than calculated speeds) and they should be worse if RSX and GDDR3 access are involved because these figures were measured when the RSX was clocked at 550Mhz and the GDDR3 memory was clocked at 700Mhz. The shipped PS3 has the RSX clocked in at 500Mhz (front and back end, although the pixel shaders run separately inside at 550Mhz). In addition, the GDDR3 memory was also clocked lower at 650Mhz.

{|class="wikitable"
|-
! Processor !! 256MB XDR !! 256MB GDDR3
|-
| Cell Read || 16.8GB/s || 16MB/s
|-
| Cell Write || 24.9GB/s || 4GB/s
|-
| RSX Read || 15.5GB/s || 22.4GB/s
|-
| RSX Write || 10.6GB/s || 22.4GB/s
|-
|}

Because of the VERY slow Cell Read speed from the 256MB GDDR3 memory, it is more efficient for the Cell to work in XDR and then have the RSX pull data from XDR and write to GDDR3 for output to the HDMI display. This is why extra texture lookup instructions were included in the RSX to allow loading data from XDR memory (as opposed to the local GDDR3 memory). 

==RSX Libraries==
The RSX is dedicated to 3D graphics, and developers are able to use different API libraries to access its features. The easiest way is to use high level PSGL, which is basicially OpenGL|ES with programmable pipeline added in. At a lower level developers can use LibGCM, which is an API that talks to the RSX at a lower level. PSGL is actually implemented on top of LibGCM. For the advanced programmer, you can program the RSX by sending commands to it directly using C or assembly. This can be done by setting up commands (via FIFO Context) and DMA Objects and issuing them to the RSX via DMA calls.

Source: http://www.edepot.com/playstation3.html#PS3_RSX_GPU

== Other References ==
*http://7track.org/~durandal/ps3dox/
*http://wiki.ps2dev.org/ps3:rsx