PowerColor Radeon R9 390 PCS+ 8GB review - The Technology & DirectX 12

The AMD Refresh Lineup

So, as you guys know AMD has been respinning their GPUs quite a bit, the oldest one is 3 years old, the Hawaii GPU as reviewed today actually already has been with us ever since late 2013, you know it as the GPU used in the Radeon R9 290 and 290X. For a quick refresh here's an overview.
 

• The Hawaii GPU used on the Radeon R9 290X is now used in the Radeon R9 390X but rebranded to Grenada. This series is positioned against the GeForce GTX 970 and 980.
• The R9 285 is Tonga, which is to be the R9 380, this chip will now be renamed to "Antigua" and is positioned against the GeForce GTX 960. Tonga/Antigua does offer Direct3D feature-level 12_0 support.
• The Radeon R7 270 series (First Pitcairn (AKA Radeon 7800 released three years ago) then called Curacao) will be the 370 series tagged as Tobago. The 260 (Bonaire) is gonna be the 360 series. And so on.
• The one new chip is of course Fiji, it will get two SKUs, based on a Pro and XT GPU model. We expect a liquid cooled version, and likely a lower clocked less specced Pro model with air-cooling of some sort. Probably just one SKU will launch initially though. 

R9 290 (Hawaii Pro)

• Stream Processors 2560
• Clock Frequency up-to 947 MHz
• 4.9 TFLOPS compute performance
• 4 GB memory at 5.0 Gbps / 512-bit
• 250W TDP
• PCI-E 3.0
• API - DirectX 12 / OpenGL 4.4 / Mantle

The GPU architecture has remained the same though comparable towards the last-generation products, AMD still uses the 28 nm process technology, the cards are PCIe gen 3 compatible and there have been significant changes on power consumption.

Direct X 12 - feature level support

With Windows 10 just around the corner there has been a lot of talk about DirectX 12 support for the AMD refresh graphics cards. DX12 is going to be a massive improvement for PC gaming. The low DX API overhead is going to work wonders in terms of CPU utilization and increased numbers of objects in a 3D scene thanks to that low overhead. AMD does support DirectX 12, but not completely (but neither does Nvidia with the previous-gen products). The current generation GCN based GPUs don’t offer full DirectX 12 support, they are limited to Feature Level 11_1 & 12_0 while the competition with Maxwell have full Feature Level 12_1 support.

Make no mistake though, while the higher feature level is not supported, the most important ones, low API overhead and tiled resource, are supported. For GPUs of this age there thus indeed is proper DX12 support, at the very least for the most important features.

The reference DirectX 12 API (Feature Level 11_0) offers performance aimed features, two other levels offer graphics quality features. Feature level 12_0 comes with Tiled Resources, Typed UAV Access and Bindless Textures support. Feature Level 12_1 has the Raster Order Views, Conservative Raster and Volume Tiled Raster enabled on the API. For AMD this means that their latest cards will support Feature Level 12_0 - NVIDIA’s Maxwell 2.0 architecture (900 series) have support for Feature Level 12_1. AMD cards that feature level 12_ 0 support include cards as old as Radeon HD 7790, Radeon R7 260 (X), Radeon R9 285, Radeon R9 290 (X) and R9 295X2.

AMD's Robert Hallock stated that there’s no problem with not featuring DirectX Feature Level 12_1 support since features are performance enhancing tools which are already available in 11_1 and 12_0 and most games won’t rely on utilization of 12_1. So this is all directly related to the GCN revision, in an overview it would look a little something like this,

For those interested, here's an overview for Nvidia as well for fair comparison:

More info on partial support can be found here.