It looks like AMD's claims of HD 7970's extreme overclocking capabilities weren't the usual PR hoopla. A confidential company document revealing the non-reference models Sapphire has in the works, got leaked to the web, and it is a bundle of surprises. To begin with, Sapphire plans no less than six non-reference Radeon HD 7970 models apart from the vanilla AMD reference design card. Among these, the top-of-the-line cards are codenamed "Atomic RX" and "Atomic WC". One can guess that the "RX" is an air-cooled card, and the "WC" a water-cooled one. It packs blistering clock speeds of 1335 MHz core, with 5735 MHz (1433 MHz actual) memory.The other card that caught our eyes is codenamed "FLEX 6G". The Flex variant typically features a flexible display output configuration. This card is said to have six mini-DP connectors. While this card sticks to AMD reference clock speeds, it packs a whopping 6144 MB of video memory, all wired to a single GPU. While 4 Gbit GDDR5 chips don't exist, we expect Sapphire to be using 24 * 2 Gbit chips on this card, with twelve sets of two chips sharing 32 bit paths. Then there are other milder factory overclocked cards apart from the Atomic; there's Toxic 3G, and VaporX 3G, both packing impressive out of the box clock speeds.