A mysterious variant of AMD's Radeon RX 570 has appeared over at the Saraba1st (via Twitter user HXL) forums. The graphics card appears to feature two Ellesmere GPUs on a single PCB, effectively doubling its mining performance. It's uncertain if this is a new AMD product or just an AIB partner that got creative with the design.
The dual-slot graphics appears to hail from Sapphire's camp as evidenced by the small logo on one of the chokers hidden under the shroud. According to the GPU-Z screenshot, PC Partner is the OEM who manufactured the graphics card. The model name is unknown so the graphics card has been unofficially baptized as the Radeon RX 570 Duo for now.
It's interesting that GPU-Z didn't have any problems detecting the Radeon RX 570 Duo. The software only detected a single Ellesmere GPU on the Radeon RX 570 Duo, though. However, the photograph of the graphics card's PCB clearly confirms the presence of two GPUs. The Radeon RX 570 Duo checks in with a 1,120 MHz base clock and 1,150 MHz boost clock. By comparison, the clock speeds are even lower than the original Radeon RX 570, but that's normal for a mining graphics card. Sapphire probably kept the clock speeds as low as possible to optimize power consumption.
So, where did all the power budget go? To the memory, of course. The Radeon RX 570 Duo comes equipped with 16GB of GDDR5 memory in a 8+8 configuration. The memory interface remains unchained at 256-bit. As per the GPU-Z screenshot, the memory is clocked at 2,100 MHz (8.4 Gbps effective). The Radeon RX 570's memory checks in at 1750 MHz (7 Gbps effective), so the memory overclock on the Radeon RX 570 Duo represents a 20% increase.
A single Radeon RX 570 8GB offers a mining performance in the range of 28 MH/s before optimization. The Radeon RX 570 Duo, on the other hand, reportedly hits a hash rate of 59.72 MH/s. This make sense since there are two Ellesmere dies onboard. A hash rate of 60 MH/s basically puts the aging AMD graphics card on the same level as the GeForce RTX 3060 Ti preceding the Ampere mining nerf.
The screenshot claims that the Radeon RX 570 Duo draws 125W, which is unlikely. The vanilla Radeon RX 570 8GB pulls 130W alone so there's no way two Ellesmere GPUs only sip 125W. Therefore, take that power value with a grain of salt.
The Radeon RX 570 Duo sports a simple, black shroud with two cooling fans. There's even a HDMI port so it can function as a normal gaming graphics card. Each Ellesmere die has its own heatsink with a couple of copper heat pipes for heat transfer.
The PCIe power connectors are located at the rear of the graphics card. Although the photographs don't clearly show the connectors, the PCB traces correspond to two 8-pin PCIe power connector, which puts us in doubt of the 125W power consumption claims. For reference, the Radeon RX 570 is rated for 150W and relies on a single 6-pin PCIe power connector.
GlobalFoundries originally produced the Ellesmere silicon for AMD on the foundry's 14nm process node. We don't think AMD had GlobalFoundries restart the furnace so it's plausible that Sapphire has some leftover inventory of Ellesmere dies that the brand needed to get rid of.
One user from the Saraba1st forums stated that he paid 5,300 yuan or $818 for the Radeon RX 570 Duo. That's a pretty steep price, considering that, if you hunt long enough, you can pick up two Radeon RX 6600 XT and get the same mining performance. Even though AMD didn't design RDNA 2 specifically for mining, the Radeon RX 6600 XT has proven to be very efficient at it. With some tuning and patience, you can get 32 MH/s out of the Navi 23 graphics card with a power draw around 75W.