Sapphire is developing a premium variant of its upcoming Radeon RX 590 series, called the RX 590 NITRO+ Special Edition, much like the "limited edition" branding it gave its premium RX 580-based card. Komachi Ensaka accessed leaked brochures of this card, which will bear an internal SKU code 11289-01. The brochure also confirms that the RX 590 features an unchanged 2,304 stream processor count from the RX 580, and continues to feature 8 GB of GDDR5 memory across a 256-bit wide memory interface. All that's new is improved thermals from a transition to the new 12 nm FinFET silicon fabrication process.

The Sapphire RX 590 NITRO+ SE ships with two clock-speed profiles, that can be probably toggled on the hardware by switching between two BIOS ROMs. The first profile is called NITRO+ Boost, and it runs the GPU at 1560 MHz, and the memory at 8400 MHz (GDDR5-effective). The second profile, called Silent Mode, reduces the engine clock boost to 1545 MHz, and the memory to 8000 MHz. For both profiles, the fan settings are unchanged. The fans stay off until the GPU is warming up to 54 °C, and spins at its nominal speed at 75 °C. It cuts off at 45 °C. The nominal speed is 0 - 2,280 RPM and the maximum speed is 3200 RPM.Sapphire's RX 590 NITRO+ features a similar product design to its RX 580 NITRO+ Limited Edition, which detachable fans ventilating a dense aluminium fin-stack heatsink, which draws heat from the GPU over a pair of 8 mm-thick heat pipes. The card draws power from a combination of 6-pin and 8-pin PCIe power connectors. The underlying PCB is slightly different from that of its predecessor, in that Sapphire appears to have switched to higher current chokes for its 6-phase VDDC VRM. The company is also using a premium 8-layer PCB. Pricing of the card is up in the air, although an eager beaver Newegg marketplace reseller in Canada has it up for $499.