Editing PowerVR (section)

===Series3 (STMicro)===

In 2000, the third generation '''PowerVR3''' STG4000 ''KYRO'' was released, manufactured by new partner [[STMicroelectronics]]. The architecture was redesigned for better game compatibility and expanded to a dual-pipeline design for more performance. The refresh STM PowerVR3 KYRO II, released later in 2001, likely had a lengthened pipeline to attain higher clock speeds<ref>{{Cite web|url=https://www.anandtech.com/show/735|title=STMicroelectronics Kyro II 64MB|first=Matthew|last=Witheiler|website=www.anandtech.com}}</ref> and was able to rival the more expensive ATI [[Radeon]] DDR and NVIDIA [[GeForce 2]] GTS in some benchmarks of the time, despite its modest specifications on paper and lack of hardware [[transform and lighting]] (T&L), a fact that Nvidia especially tried to capitalize on in a confidential paper they sent out to reviewers.<ref>{{cite web |url=http://dumpster.hardwaretidende.dk/dokumenter/nvidia_on_kyro.pdf |title=Whay you should know |date=2001 |website=dumpster.hardwaretidende.dk |access-date=2021-01-18}}</ref> As games increasingly started to include more geometry with this feature in mind, the KYRO II lost its competitiveness.

The KYRO series had a decent featureset for a budget-oriented GPU in their time, including a few Direct3D 8.1-compliant features such as 8-layer multitexturing (not 8-pass) and Environment Mapped Bump Mapping (EMBM); Full Scene Anti-Aliasing (FSAA) and Trilinear/Anisotropic filtering were also present.<ref>{{Cite web|url=https://www.imaginationtech.com/news/press-release/imagination-technologies-powervr-in-stmicroelectronics-kyro-pc-graphics-accelerator-unveiled/|archive-url=https://web.archive.org/web/20211127164455/https://www.imaginationtech.com/news/press-release/imagination-technologies-powervr-in-stmicroelectronics-kyro-pc-graphics-accelerator-unveiled/|url-status=dead|archive-date=November 27, 2021|title=Imagination Technologies' PowerVR™ in STMicroelectronics' KYRO™ PC Graphics Accelerator Unveiled|website=Imagination}}</ref><ref>{{Cite web|url=https://www.imaginationtech.com/news/press-release/stmicrolectronics-announces-next-generation-kyro-ii-3d-graphics-accelerator/|title=STMicrolectronics announces next generation KYRO II ™ 3D Graphics Accelerator|website=Imagination|access-date=2021-01-18|archive-date=2021-01-22|archive-url=https://web.archive.org/web/20210122030918/https://www.imaginationtech.com/news/press-release/stmicrolectronics-announces-next-generation-kyro-ii-3d-graphics-accelerator/|url-status=dead}}</ref><ref>{{Cite web|url=https://www.imaginationtech.com/news/press-release/powervr-technologies-debuts-kyro-ii-se-graphics-processor-at-cebit-2002/|title=PowerVR Technologies Debuts KYRO II SE™ Graphics Processor at CeBIT 2002|website=Imagination|access-date=2021-01-18|archive-date=2021-01-22|archive-url=https://web.archive.org/web/20210122184445/https://www.imaginationtech.com/news/press-release/powervr-technologies-debuts-kyro-ii-se-graphics-processor-at-cebit-2002/|url-status=dead}}</ref> KYRO II could also perform Dot Product (Dot3) Bump Mapping at a similar speed as GeForce 2 GTS in benchmarks.<ref>{{Cite web|url=https://aceshardware.com/Spades/read.php?article_id=25000237|archive-url=https://web.archive.org/web/20020202062747/https://aceshardware.com/Spades/read.php?article_id=25000237|url-status=dead|archive-date=February 2, 2002|title=Ace's Hardware|date=February 2, 2002}}</ref> Omissions included hardware T&L (an optional feature in Direct3D 7), Cube Environment Mapping and legacy 8-bit paletted texture support. While the chip supported [[S3TC]]/DXTC texture compression, only the (most commonly used) DXT1 format was supported.<ref>{{Cite web|url=https://www.beyond3d.com/content/reviews/13/4|title=Beyond3D - Imagination Technologies Videologic Vivid! 32MB KYRO|website=www.beyond3d.com}}</ref> Support for the proprietary PowerSGL API was also dropped with this series.

16-bit output quality was excellent compared to most of its competitors, thanks to rendering to its internal 32-bit tile cache and downsampling to 16-bit instead of straight use of a 16-bit framebuffer.<ref>{{cite web |url=https://www.vogons.org/download/file.php?id=20346 |title=Data|website=www.vogons.org|access-date=2021-01-18}}</ref> This could play a role in improving performance without losing much image quality, as memory bandwidth was not plentiful. However, due to its unique concept on the market, the architecture could sometimes exhibit flaws such as missing geometry in games, and therefore the driver had a notable amount of compatibility settings, such as switching off the internal Z-buffer. These settings could cause a negative impact on performance.

A second refresh of the KYRO was planned for 2002, the STG4800 KYRO II SE. Samples of this card were sent to reviewers but it does not appear to have been brought to market. Apart from a clockspeed boost, this refresh was announced with a "EnT&L" HW T&L software emulation, which eventually made it into the drivers for the previous KYRO cards starting with version 2.0. The STG5500 KYRO III, based upon the next-generation '''PowerVR4''', was completed and would have included hardware T&L but was shelved due to STMicro closing its graphics division.

<gallery mode="packed" heights="150px">
File:Hercules 3D Prophet 4000XT 64MB PCI.png|Hercules 3D Prophet 4000XT 64MB PCI with the KYRO chipset.
File:STMicroelectronics@250nm@PowerVR Series3@STG-4000@ST Kyro@STG4000-X A3S F 42775.1 9224L0149 MALTA DSC04968.jpg|The Hercules 3D Prophet 4000XT aside a Kyro chipset
File:STMicroelectronics@250nm@PowerVR Series3@STG-4000@ST Kyro@STG4000-X A3S F 42775.1 9224L0149 MALTA DSCx6 polysilicon@5x.jpg|Die shot of the Kyro chipset
File:STMicroelectronics STG4500 (PowerVR Kyro II).png|KYRO II.
File:STMicroelectronics@180nm@PowerVR Series3@STG-4500@ST Kyro II@STG4500-X A2S F40557.1 9H27L0111 KOREA DSCx5 polysilicon-layer@5x.jpg|Die shot of the Kyro II
</gallery>
* All models support [[DirectX]] 6.0
{| class="wikitable" style="text-align: center"
|-
!rowspan=2|Model
!rowspan=2|Launch
!rowspan=2|Fab ([[nanometer|nm]])
!rowspan=2|Memory ([[Mebibyte|MiB]])
!rowspan=2|Core clock ([[Hertz|MHz]])
!rowspan=2|Memory clock ([[Hertz|MHz]])
!rowspan=2|Core config<sup>1</sup>
!colspan=4|[[Fillrate]]
!colspan=3|Memory
|-
!MOperations/s
!MPixels/s
!MTexels/s
!MPolygons/s
!Bandwidth ([[Gigabyte|GB]]/s)
!Bus type
!Bus width ([[bit]])
|-
!STG4000 KYRO
|2000<ref>{{Cite web |title=Már kapható a PowerColor Evil Kyro 64MB |url=https://www.hwsw.hu/hirek/6549/mar-kaphato-a-powercolor-evil-kyro-64mb.html |access-date=2022-05-08 |website=HWSW |language=hu}}</ref>
|250
|32/64
|115
|115
|2:2
|230
|230
|230
|0
|1.84
|SDR
|128
|-
!STG4500 KYRO II
|2001
|180
|32/64
|175
|175
|2:2
|350
|350
|350
|0
|2.8
|SDR
|128
|-
!STG4800 KYRO II SE
|2002
|180
|64
|200
|200
|2:2
|400
|400
|400
|0
|3.2
|SDR
|128
|-
!STG5500 KYRO III
|Never Released
|130
|64
|250
|250
|4:4
|1000
|1000
|1000
|0
|8
|DDR
|128
|-
|}

* <sup>1</sup> [[Texture mapping unit]]s: [[render output unit]]s