AMD Radeon R9 M295X Mobility Chip To Feature Tonga GPU – Includes 32 Compute Units


Over buddies over at Videocardz have got hands on some exclusive information regarding AMD's upcoming Radeon R9 M295X mobility chip which features the latest Tonga GPU architecture. The Tonga GPU which is AMD's new architecture is part of the new Volcanic Islands GCN 2.0 line which is built to deliver better power efficiency.AMD Tonga GPU

AMD Radeon R9 M295X Mobility Chip To Feature Tonga GPU

Leaked last month, we came to know that the Tonga GPU architecture is being built on a new architecture which is presumably the GCN 2.0 design and not the GCN 1.1 architecture which has been featured on Bonaire and Hawaii. The Tonga graphics architecture will be built on the 28nm node from Global Foundries and would feature a new design scheme introducing latest architectural improvements such as new ACE (Asynchronous Compute Engine) Units and more focus towards compute shaders. It is also mentioned that Tonga will retain the basic technologies of the Radeon lineup such as Mantle, TrueAudio and XDMA for CrossFire support.

Now Videocardz was able to find some specifications of the Tonga GPU which is meant to replace the Pitcairn and its rebranded subsidiaries that include Curacao on desktop and Neptune on mobility front. Technically, the Tonga GPU falls in line with the Tahiti GPU but due enhanced efficiency, it'll be aimed towards the same range as AMD's Pitcairn series cards (Radeon R9 270 / Radeon R9 270X / Radeon R9 M290X). The interesting thing is that Tonga will feature 32 compute units but since the architecture is slightly improved, we don't know whether the stream processor count would remain the same. Otherwise we are looking at 2048 stream processors for each compute unit that includes 64 processors. The GPU in such a case will feature 128 TMUs and 32 ROPs which is the standard for Tahiti GPU along with a 256-bit bus width which seems like a downgrade compared to Tahiti but that could explain why its aimed as a Pitcairn replacement.

The Tonga GPU being a mobility chip confirms that its efficient enough to be adopted in high-end notebook and mobility devices. AMD for a reason didn't went to integrate Tahiti or Hawaii into high-performance notebooks due to their high power consumption. Tonga might just change the game and offer competitive performance against the GeForce GTX 880M which is a full GK104 core in mobility form factor. Though the mainstream note-books featuring the GeForce GTX 860M and 850M Maxwell cores will still look like a better power efficient offering.

Clock speeds at reference are not mentioned but the core will operate at a max boost clock of 800 MHz and the memory would operate at 1375 MHz (5.5 GHz effective) clock speed. The AMD Radeon R9 M295X mobility chip will end up with 4 GB GDDR5 memory. Its desktop equivalent which is likely to use the Radeon R9 275X branding will feature the same GPU with better clock speeds. The key focus is power efficiency on Tonga GPU hence we can see some good numbers in that regard.

Videocardz also mentions that since AMD is using the 295X branding on mobility chips, we may soon see a better binned Hawaii GPU called the Radeon R9 295X which may feature boosted clocks compared to 1000 MHz on the Radeon R9 290X. This would be somewhat similar to the Radeon HD 7970 GHz and Radeon HD 7970 GE editions we saw that were released months after the launch of Radeon HD 7970 in January 2012.

AMD Radeon R9 M295X Tonga GPU Specs Sheet:

AMD Radeon R9 M290X AMD Radeon R9 M295X AMD Radeon R9 275X AMD Radeon R9 280X AMD Radeon R9 290X AMD Radeon R9 295X
GPU Core Neptune XT Tonga Tonga Tahiti XT Hawaii XT Hawaii XTX
GPU Process 28nm 28nm 28nm 28nm 28nm 28nm
GPU Cores 1280 2048 2048 2048 2816 2816
Core Clock 900 MHz 800 MHz ~800 MHz 1000 MHz 1000 MHz ~1100 MHz
Memory Clock 1200 MHz 1375 MHz 1375 MHz? 1500 MHz 1250 MHz ~1250 MHz
Memory Bus 256-bit 256-bit 256-bit 384-bit 512-bit 512-bit
Memory Bandwidth 153.6 GB/s 176 GB/s 176 GB/s 288.0 GB/s 320 GB/s 320 GB/s
TMUs / ROPs 80 / 32 128 / 32 128 / 32 128 / 32 176 / 64 176 / 64