More information continues to leak regarding AMD's upcoming Radeon R9 300-series, and in this instance perennial rumour site WCCFTech.com have acquired a set of images believed to be showing AMD's not-quite flagship SKU based on the Fiji GPU - the Radeon R9 390. First seen (as they so often are) on a Chinese tech forum, the pictures show an XFX branded design with non-reference cooler and some additional features giving advanced indication of the card's design.
As stated, the first point of note is that the card makes use of a non-reference cooler design, nominally similar to the Double Dissipation model XFX uses on many of their overclocked graphics cards. Aesthetic features differ, including the use of illuminated Radeon logo and gold trim, but both 100m diameter fans and an extensive aluminium heatsink under the hood speak to its likely effectiveness. It seems likely that this cooler would also be used with the flagship R9 390X.
Coupled to a non-reference cooler is likely a non-reference PCB, most notably taller than usual dual-slot designs. The DRAM layout isn't clear from these pictures, however the R9 390 is anticipated to make use of stacked (HBM) memory positioned alongside the GPU on an interposer layer. Not only would this lead to a larger package overall (the size of the interposer layer rather than just the GPU), it would also concentrate cooling requirements around the GPU even more than traditional layouts. Stacked memory has the potential to greatly increase memory bandwidth, with AMD likely most limited by cost and the number of RAM chips they can efficiently fit on the interposer layer.
As expected from a high-end card, especially one with overclocking potential, the images show both 6-pin and 8-pic PCIe power connectors, supplying up to 225W for 300W total (75W supplied through PCIe 3.0 bus). This is in stark contrast to Nvidia's GTX 980 reference designs, and much more akin to the requirements of the Titan X. It shall be interesting to see how AMD shape up in terms of power efficiency, and if the R9 390X has even more voracious demands.
The only other clear features are the continued inclusion of a DVI port and the lack of a visible CrossFire connector. Since the introduction of the R9 290 AMD have made use of XDMA Crossfire via the main 16x PCI-Express 3.0 slot rather than a bridge connector, and that appears to continue with the Radeon R9 390.
More detailed technical specifications for both the R9 390 and R9 390X are tentative at best. Leaked specifications indicate a GPU with 4096 shaders built on the latest iteration of AMDs GCN architecture, 4 or 8GB of memory, bus width of 1024-bit and memory clocks of 1.25GHz; however as with all rumours should be taken with a pinch of salt.
For more information check out WCCFTech's article on the latest leak.