Finding documentation for legacy GPUs on Hackintoshes has been pretty difficult from my experience, so I'm creating this post to provide more documentation for them.

Do note I don't have experience with all legacy GPUs, this is all going off the little documentation I can find, and I've added the info I do know for ones I have used in macOS. If you have anything you want me to add, tell me in the comments. I recommend using ctrl+f/cmd+f to search through the post to find your GPU. This guide supports ATI (AMD), NVIDIA, and Intel.

ATI Radeon HD 6xxx/FirePro V7900

These are supported from Snow Leopard (10.6.x) to High Sierra (10.13.x). The 6750, 6770, 6930 and 6990 are not supported and won't get acceleration. Other cards have no issues as far as I know. For support in Mojave (10.14.x) and Catalina (10.15.x), you can use dosdude1 patchers, and for Big Sur (11.x) and later, you can use OCLP. Do note that this is unsupported by both dosdude1/OCLP and the hackintosh community, and you may experience issues as these GPUs are not metal capable. WhateverGreen is recommended.

ATI Radeon HD 5xxx

These are supported from Snow Leopard (10.6.x) to High Sierra (10.13.x). The 5550, 5610, 5750, 5830, and 5970 are not supported and won't get acceleration. Other cards have no issues as far as I know. For support in Mojave (10.14.x) and Catalina (10.15.x), you can use dosdude1 patchers, and for Big Sur (11.x) and later, you can use OCLP. Do note that this is unsupported by both dosdude1/OCLP and the hackintosh community, and you may experience issues as these GPUs are not metal capable. WhateverGreen is recommended.

ATI Radeon HD 4xxx

Only the HD 4870 model is supported. It is supported from Snow Leopard (10.6.x) to High Sierra (10.13.x). The 4870 doesn't have any major issues, other models won't get acceleration. For support in Mojave (10.14.x) and Catalina (10.15.x), you can use dosdude1 patchers, and for Big Sur (11.x) and later, you can use OCLP. Do note that this is unsupported by both dosdude1/OCLP and the hackintosh community, and you may experience issues as this GPU is not metal capable. WhateverGreen is recommended.

ATI Radeon HD 3xxx

Only the HD 3870 model is supported. It is supported from Tiger (10.4.x) to High Sierra (10.13.x). The 3870 doesn't have any major issues, other models won't get acceleration. WhateverGreen is recommended for Snow Leopard (10.6.x) and later.

ATI Radeon HD 2xxx

Only the HD 2400 XT and HD 2600 XT models are supported. They are supported from Tiger (10.4.x) to High Sierra (10.13.x). As far as I know, there are no major issues with these GPUs. For support in Mojave (10.14.x) and Catalina (10.15.x), you can use dosdude1 patchers, and for Big Sur (11.x) and later, you can use OCLP. Do note that this is unsupported by both dosdude1/OCLP and the hackintosh community, and you may experience issues as these GPUs are not metal capable. WhateverGreen is recommended for Snow Leopard (10.6.x) and later.

ATI Radeon X1xxx

Only the X1900 XT, X1600, and XT1300 models are supported. They are supported from Tiger (10.4.x) to Lion (10.7.x). As far as I know, there are no major issues with these GPUs. You may be able to use NexPostFacto to get acceleration for Mountain Lion (10.8.x) and Mavericks (10.9.x), however I have not tested this. WhateverGreen is recommended for Snow Leopard (10.6.x) and later.

ATI Radeon X8xx

While these should be theoretically supported, I can't find any info on them. These should be supported from Panther (10.3.x) to Lion (10.7.x). Do note you cannot run Panther on a Hackintosh due to it being PowerPC only. These GPUs will require the arch=i386 boot-arg for Snow Leopard (10.6.x) and later, this boot-arg may break certain 64-bit applications.

Fermi (NVIDIA GeForce GTX 4xx and 5xx)

As far as I know, only the GTX 470 and GTX 570 cards are supported. These cards are supported from Lion (10.7.x) to High Sierra (10.13.x). These GPUs are known to have stability issues in High Sierra, it is recommended to use Sierra (10.12.x) instead. These cards typically require patches to get acceleration, follow Dortania's guide. WhateverGreen is recommended.

Tesla (NVIDIA GeForce GT/GTX 1xx, 2xx, and 3xx)

These are supported from Leopard (10.5.x) to High Sierra (10.13.x). These cards typically require patches to get acceleration, follow Dortania's guide. For support in Mojave (10.14.x) and Catalina (10.15.x), you can use dosdude1 patchers, and for Big Sur (11.x) and later, you can use OCLP. Do note that this is unsupported by both dosdude1/OCLP and the hackintosh community, and you may experience issues as these GPUs are not metal capable. WhateverGreen is recommended for Snow Leopard (10.6.x) and later.

NVIDIA GeForce 9xxx

These are supported from Leopard (10.5.x) to High Sierra (10.13.x). Only the 9300 GT, 9400 GT, 9600 GT, and 9800 GT are supported, other cards won't get acceleration. These cards typically require patches to get acceleration, follow Dortania's guide. For support in Mojave (10.14.x) and Catalina (10.15.x), you can use dosdude1 patchers, and for Big Sur (11.x) and later, you can use OCLP. Do note that this is unsupported by both dosdude1/OCLP and the hackintosh community, and you may experience issues as these GPUs are not metal capable. WhateverGreen is recommended for Snow Leopard (10.6.x) and later.

NVIDIA GeForce 8xxx/FX 5600

These are supported from Leopard (10.5.x) to High Sierra (10.13.x). Only the 8800 and FX 5600 are supported, other cards won't get acceleration. These cards typically require patches to get acceleration, follow Dortania's guide. For support in Mojave (10.14.x) and Catalina (10.15.x), you can use dosdude1 patchers, and for Big Sur (11.x) and later, you can use OCLP. Do note that this is unsupported by both dosdude1/OCLP and the hackintosh community, and you may experience issues as these GPUs are not metal capable. WhateverGreen is recommended for Snow Leopard (10.6.x) and later.

NVIDIA GeForce 7xxx/FX 4500

These are supported from Panther (10.3.x) to Lion (10.7.x). Do note you cannot run Panther on a Hackintosh due to it being PowerPC only. Only the 7600 GT, 7300 GT, and FX 4500 are supported, other cards won't get acceleration. These cards typically require patches to get acceleration, follow Dortania's guide. WhateverGreen is recommended for Snow Leopard (10.6.x) and later.

NVIDIA GeForce 6xxx

These are supported from Panther (10.3.x) to Lion (10.7.x). Do note you cannot run Panther on a Hackintosh due to it being PowerPC only. Only the 6600 GT is supported, other cards won't get acceleration. This card will require the arch=i386 boot-arg for Snow Leopard (10.6.x) and later, this boot-arg may break certain 64-bit applications. This card typically require patches to get acceleration, follow Dortania's guide.

Sandy Bridge (Intel Core ix-2xxx)

These are supported from Snow Leopard (10.6.x) to High Sierra (10.13.x). The Intel HD Graphics 2000 model (typically found in desktops) will not receive acceleration. The HD 3000 models have no known issues. For support in Mojave (10.14.x) and Catalina (10.15.x), you can use dosdude1 patchers, and for Big Sur (11.x) and later, you can use OCLP. Do note that this is unsupported by both dosdude1/OCLP and the hackintosh community, and you may experience issues as these GPUs are not metal capable. WhateverGreen is recommended.

Lynnfield/Clarkdale/Clarksfield/Arrandale (Intel Core ix-xxx)

These are supported from Snow Leopard (10.6.x) to High Sierra (10.13.x). In most cases, these are unsupported. The only exception is laptops with LVDS displays, and external outputs will not work. follow this guide to see how your display is connected. WhateverGreen is recommended.

Fourth generation Intel GMA (Intel GMA xxxx)

These are supported from Leopard (10.5.x) to Lion (10.7.x). Only the GMA X3100 model is supported, other models won't receive acceleration. This card will require the arch=i386 boot-arg for Snow Leopard (10.6.x) and later, this boot-arg may break certain 64-bit applications. This card typically require patches to get acceleration, follow Dortania's guide. In Lion, you may get a kernel panic from AppleIntelGMAX3100 when using OpenCore, the only solution is switching to Clover or Chameleon. You can use MLPostFactor to get acceleration in Mountain Lion (10.8.x), do note this is unsupported by both the hackintosh community and MLPostFactor, and OS X won't boot with MLPostFactor if you're using OpenCore or a Clover revision later than r5123.

Third generation Intel GMA (Intel GMA xxx)

These are supported from Leopard (10.4.x) to Lion (10.7.x). Only the GMA 950 and 900 models is supported, and the GMA 900 may have issues in Lion. other models won't receive acceleration. This card will require the arch=i386 boot-arg for Snow Leopard (10.6.x) and later, this boot-arg may break certain 64-bit applications. This card typically require patches to get acceleration, follow Dortania's guide. You can use MLPostFactor to get acceleration in Mountain Lion (10.8.x), do note this is unsupported by both the hackintosh community and MLPostFactor, and OS X won't boot with MLPostFactor if you're using OpenCore or a Clover revision later than r5123.