Earlier this day, HP announced its newest line of desktop PCs, one of which comes with a curious-sounding Radeon R9 380 graphics card. HP's product pages for its new desktops aren't active, yet, leaving us to only speculate on what the R9 380 could be. One theory making rounds says that the R9 380 could either be a re-branded R9 285, or be based on its "Tonga" silicon, which physically features 2,048 stream processors based on Graphics CoreNext (GCN) 1.2 architecture, and a 384-bit wide GDDR5 memory interface. Another theory states that the R9 380 could be an OEM-only re-brand of the R9 280 or R9 280X, based on the 3+ year old "Tahiti" silicon.The former theory sounds more plausible, because re-branding a "Tahiti" based product would be suicidal for AMD. Although based on GCN, "Tahiti" lacks a lot of architecture features introduced with "Hawaii" and "Tonga." AMD practically stopped optimizing games for "Tahiti," and some of its new features, such as FreeSync and XDMA CrossFire, can't be implemented on it. "Tonga," on the other hand, supports both these features, and one can create an SKU with all its 2,048 stream processors, and its full 384-bit GDDR5 memory interface unlocked. If the R9 380 is indeed an OEM-only product, then it's likely that the company's retail-channel products could be branded in the succeeding R9 400 series. GPU makers tend to re-brand and bump their SKUs by a series for OEMs to peddle in their "new" products at short notice.Our most recent understanding of AMD's next-gen lineup sees re-branding across the lineup, with just one genuinely new silicon. "Tonga" could drive the pair of SKUs that directly succeed the R9 270 and R9 270X; "Grenada," which is a refined version of "Hawaii," will drive the SKUs that succeed the R9 280 and R9 280X; while the new "Fiji" silicon, with its 4,096 stream processors and a fancy 640 GB/s HBM memory interface, could drive the SKUs that succeed R9 290 and R9 290X. An extraordinary rumor doing rounds is that one "Fiji" SKU could get a fancy model name à la NVIDIA Titan.