AMD wasn’t always NVIDIA’s main competitor. ATI, the company who produced GPUs independently before being acquired by AMD, kicked off with their starting lineup in the mid to late 80’s, beginning with the ATI “Wonder” series. These chips were impressive and quite unique, as they “combined support for multiple graphics standards [and monitors] into a single card”.

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Specifications:
ATI 18800
DRAM: 256/512kb
Output: 9-Pin D-sub/15-pin D-sub
Original market price: $249
Die Size: 90mm^2
Process Size: 800nm
Pixel Shaders: 1

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Clearly, much has changed between then and now. Today, you couldn’t run your current operating system on an ATI Wonder series card. Back then, advancement in technology was fast, and ATI moved on to producing their Mach series of cards in the 90s, and later, the famous Radeon series. The Mach 32 series featured more DRAM, more color modes, and a 64 bit memory interface, and the Mach 64 series doubled up on practically everything the 32 series offered.

Image:[spoiler][img]https://i.gyazo.com/fe16b632a9a49b0acd15769ce902e717.png[/img][/spoiler]

Specifications:
ATI mach64 VT
DRAM: 1/2MB
Output: VGA/15-pin D-sub
Original market price: $239
Die Size: 90mm^2
Process Size: 600nm
Pixel Shaders: 1

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Before jumping into ATI’s Radeon line, there was the ATI Rage line, which bridged 2D and 3D graphics acceleration. One popular budget option was the ATI 3D Xpression/Rage GPU. It featured DirectX 5.0 and was a very small chip for its time.

Image:[spoiler][img]https://tpucdn.com/gpu-specs/images/c/1716-front.small.jpg[/img][/spoiler]

Specifications:
ATI 3D Rage
DRAM: 2MB
Output: VGA/15-pin D-sub
Original market price: $179
Die Size: 39mm^2
Process Size: 500nm
Pixel Shaders: 1

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Now, we get into the real meat and potatoes of ATI’s (and later, AMD’s) greatest work. The ATI Radeon series kicked off with the R100 series in April of 2000, bringing support for OpenGL 1.3 and Direct3D 7.0. Multiple displays were also supported. This is where we see the spike in technological advances begin to take hold, as the DRAM available on cards sporting the RV100 chip started at 32MB and went up to 64MB. These chips also supported line & edge anti aliasing, texture caching, DirectX7.0, and full-screen anti aliasing. Things were starting to take off!

Image:[spoiler][img]https://upload.wikimedia.org/wikipedia/commons/thumb/d/d7/Radeon_RV100_DDR.JPG/1920px-Radeon_RV100_DDR.JPG[/img][/spoiler]

Image:[spoiler][img]https://i.gyazo.com/2263bdb34b12e4f47a09fd61a9da94d1.png[/img][/spoiler]

Specifications:
ATI Radeon DDR/ATI Radeon 7000 SDR 32MB
DRAM: 32MB
Output: 2xVGA/15-pin D-sub
Original market price: $79
Die Size: 80mm^2
Process Size: 180nm
Pixel Shaders: 1

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The Radeon line of GPUs improved with each generation, with each new generation chip trying to outpace NVIDIA’s chips. Newer and newer versions of DirectX and OpenGL were supported and gamers across the world rejoiced at the sight of such quick advancement in graphics processing. Clock speeds, frame rates, and memory capacities increased every single year!
Additionally, cards were beginning to need active fan coolers & heatsinks instead of passively cooled heatsinks.
Important milestone cards:
ATI Radeon 9200 - 250MHz Core Clock, 4 pixel shaders
Image: [spoiler][img]http://www.vgamuseum.info/media/k2/items/cache/398a8bc2e3f7f879ff0986359513be80_S.jpg[/img][/spoiler]
ATI Radeon 9700 - 325MHz Core Clock 4 pixel shaders
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ATI Radeon X800 GTO - 400MHz Core Clock, 12 pixel shaders
Image: [spoiler][img]https://tpucdn.com/gpu-specs/images/c/2092-front.small.jpg[/img][/spoiler]

ATI kept cranking out the newest Radeon series card year after year, ending with the R700 GPU in 2008, after which the Radeon series began to separate itself into codenames following AMD’s acquisition of the ATI brand name. This is where your idea of a modern GPU begins to come together. Pixel shaders were thrown out for a new technology, stream processors, to rival NVIDIA’s CUDA Core technology. This was the next big leap in GPU processing power and potential. Games were getting more demanding, and AMD/NVIDIA both had to up the ante to enable game developers to push the limits of 3D environments in video games.
Important milestone cards:
ATI Radeon HD 3870 X2 - 825MHz Core Clock, 320 Stream Processors (First card to break 1TFlop, 2 GPUs on one card!)
Image: [spoiler][img]https://upload.wikimedia.org/wikipedia/commons/4/40/Powercolorx2.JPG[/img][/spoiler]
ATI Radeon 4770 - 750MHz Core Clock, 640 Stream Processors.
Image: [spoiler][img]https://upload.wikimedia.org/wikipedia/commons/thumb/0/07/ATI_Radeon_HD_4770_Graphics_Card-oblique_view.jpg/220px-ATI_Radeon_HD_4770_Graphics_Card-oblique_view.jpg[/img][/spoiler]
AMD Radeon HD 6870 - 900MHz Core Clock - 1120 Stream Processors

Something to note around the 2010 era of AMD GPUs is that something like the 6870 is still usable to this day, if you just want to play basic games like Minecraft, RuneScape, and other older titles like Half-Life 2 and Portal. New display outputs were added, like HDMI, DisplayPort, mini DisplayPort, and DVI. Available VRAM is now cracking the 1GB mark, and later breaks the 6GB mark with the AMD Radeon 7990. The Radeon 7000 series of cards should still be fresh in everyone’s head at this point. The NVIDIA GTX 660 and AMD 7850 were the two most popular cards for PC Gamers, according to Steams December 2014 Hardware Survey. Titles like Battlefield 3, CoD MW3, GTAV, Bioshock Infinite, and many more were pushing computers to their limits with their new game engines, forcing AMD and NVIDIA to keep packing more processing power into their little silicon chips.
Important milestone cards:
AMD Radeon 7750 - 800MHz Core Clock, 512 Stream Processors
Image: [spoiler][img]https://images-na.ssl-images-amazon.com/images/I/71zSWHqEhtL._SL1500_.jpg[/img][/spoiler]
AMD Radeon 7850 - 860MHz Core Clock, 768 Stream Processors
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AMD Radeon 7970 and 7990 - 925/1000MHz Core Clock, 2048/2x2048 Stream Processors
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From there, graphics performance and innovation in the GPU industry has still been improving, but less so than before. Cards are being shipped with more VRAM, higher clock speeds, and more Stream Processors. From around 2014 to now, GPUs from both AMD and NVIDIA have been fitting more transistors in smaller dies and squeezing more performance out of their PCBs, while also coming up with some innovative designs. The R9 295x2 featured two GPUs on a single PCB, while also being watercooled! This trend continued with the R9 Fury X and fell back out as AMD transitioned to their Vega, RX 400, and RX 500 series of cards, which brings us to the present day.
Important milestone cards:
AMD R9 290 - 947MHz, Core Clock, 2560 Stream Processors
Image: [spoiler][img]https://assets.pcmag.com/media/images/349287-amd-radeon-r9-290.jpg?width=1000&height=809[/img][/spoiler]
AMD R9 295x2 - 1018MHz Core Clock, 2816 Stream Processors
Image: [spoiler][img]https://images.techhive.com/images/article/2014/04/amd_radeon_r9_295x2-100259790-large.jpg[/img][/spoiler]
AMD R9 Fury X - 1050MHz Core Clock, 4096 Stream Processors
Image: [spoiler][img]https://images.anandtech.com/doci/9390/R9_FuryX_Cooler_Straighton_4c_10inch_678x452.jpg[/img][/spoiler]
AMD VEGA 64 - 1200MHz Core Clock, 4096 Stream Processors
Image: [spoiler][img]https://i.redd.it/cvxn96xlons01.jpg[/img][/spoiler]
AMD RX4/580 - 1120/1257MHz Core Clock, 2304 Stream Processors
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