The guys over at 3DCenter have got a hold of information in the form of a table, which supposedly shows the schedule of RX Vega manufacturing and integration work from AMD’s add-in-board partners (which includes Sapphire, XFX, PowerColor, and others.) The way building graphics cards works is that AIB partners receive a suggested reference design from AMD as to how to incorporate their GPUs into an actually operable graphics card. This is a process which takes time.
So if we look at the leaked schedule (shown below), we can see that the BOM (Bill Of Materials) for the required parts to properly manufacture an RX Vega graphics card was to be released sometime in June, with engineering validation tests going through the end of June towards the beginning of this month (July.) Actual working samples from AIB partners are scheduled to be available in the middle of this month, with product validation tests (PPVT) going towards the beginning of August. If you remember AMD said they would formally announce Radeon RX Vega at SIGGRAPH 2017, which goes on from July 30th to August 3rd.
Finally we can see that AMD’s BIOS is only scheduled to be sent to AIB partners on August 2nd, and AIB partners still have no word on an exact launch date from AMD, which sort of limits their ability to start mass production on their designs. This could mean only a “paper” launch for Radeon RX Vega or possibly a launch with only AMD reference designs first and then AIB partner designs will come later.
Keep in mind the final source BIOS is very important to AIB partner designs as it includes info on stock AMD-defined power and temperature limits, power states and fan curve, which AIB partners use to build their custom cooling solutions.