As we've mentioned before, rebadging is one of the graphics card world's dirty little secrets. Take your existing graphics engine, tweak the clock speeds a little, and -- voila -- it's a whole new card with a spiffier-sounding product name.
AMD and Nvidia have just repeated the formula with its latest mobile graphics card lineups. While the Radeon 7000 series promises a new 28nm architecture from AMD, the first 7000M chips are actually rebadges of the 6000 family. As Anandtech details, the Radeon HD 7400M uses the same Seymore XT core as the Radeon HD 6470M, the Radeon HD 7500M uses the same Whistler LT core as the Radeon HD 6630M, and the Radeon HD 7600M uses the same Whistler Pro as the Radeon HD 6750M. In other words, they share the same number of stream processors, texture units, and memory bus width. The biggest difference will be just in the core clock speed (and the fancy new name).
Nvidia is doing the same thing with its new 600M parts. The GeForce 520MX and GeForce 610M share the same GF119 core, the GeForce GT 540M and GeForce GT 630M share the GF108 core, and the GeForce GT 555M and GeForce GT 635M share the GF106/GF108 cores. Perhaps more egregious is that GeForce 610M and GeForce GT 630M don't have any different key specs compared to their 500M series predecessors, and the GeForce GT 635M's only major difference is a memory clock speed boost for certain versions.
So get ready for laptop makers to make a big deal about new AMD and Nvidia graphics cards, but keep in mind that they aren't that new at all. In AMD's case, you'll have to wait until 2012 for the truly new Radeon 7000 series hardware.