AMD “Tonga” Block Diagram Reveals R9 285 Specifications

/ 2 years ago


Just a few days ago pictures of upcoming AMD R9 285 graphics cards were leaked into the press, such as the Sapphire R9 285 pictured above, but at that stage we were still unsure as to what the key specifications of AMD’s R9 285 were supposed to be. Well, we do know that the AMD R9 285 is going to be based on the new “Tonga” silicon and now we have information about what Tonga is made up of. The block diagram for Tonga, which you can see below, was released with the launch of AMD’s new FirePro W7100 graphics card.


There are rumoured to be two SKUs of the Tonga silicon, one SKU will make use of all 32 Compute Units (CUs) and the other will make use of 28 CUs, meaning four CUs are disabled on that one. AMD’s FirePro W7100 is based on the cut-down Tonga SKU that has 28 CUs. The 28 CU version is now being dubbed “Tonga PRO” while the 32 CU version is “Tonga XT” and is expected to launch at a later date. If rumours are to be believed AMD’s R9 285 will be based on Tonga PRO and an R9 285X will arrive later on with Tonga XT.

The R9 285 is confirmed to have the following specifications so far: 1792 stream processors, 32 ROPs, a 256 bit memory bus, 2GB of GDDR5 memory, a TrueAudio DSP and CrossFire XDMA support. Expect more information about the R9 285 to arrive as we edge closer to the expected launch this month.

Source:, Via: TechPowerUp

Image #1 courtesy of VideoCardz, Image #2 courtesy of

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