Whilst Nvidia’s Maxwell family only applies to the GTX750 Ti and the GTX750, it’s not going to be the only one. Later in the year we can expect a complete rollout of GPUs based on the 28-nanometer process, with further tweaks to Maxwell’s architecture to make it even more efficient on larger dies. AMD is set to hit back sooner with Tonga, a revamped version of the Tahiti family that makes up the Radeon HD7870XT, HD7950, HD7970, R9 280 and R9 280X.
Tonga will be a more efficient version of the GCN silicon, with VR-Zone China expecting it to pack in as much power as the R9 280X in the same power envelope as the Radeon R9 270X. VR-Zone reports that the card may have up to 2048 GCN-based stream processors, 128 texture units, 32 ROPs, a 256-bit memory bus and between 2-4GB of GDDR5 memory. With those specs, it’s closer to the Geforce GTX760, which is a cut-down, more efficient version of the GTX680.
Source: VR-Zone China