The guys over at Coolaler have allegedly been able to get their hands on an upcoming Maxwell GM204 graphics card, from what they are saying it is the GeForce GTX 870. The GPU-Z screenshot that they provide cannot property identify the GPU, but it does read the cards name as “D17U-20” featuring a GPU name “13C2”. The Device ID and BIOS fields are redacted so we cannot say for sure if this is genuine or not.
The card has a CUDA core count of 1664, which means it will have 13 streaming multiprocessors. Other specifications listed are 138 TMUs, 32 ROPs, and a 256-bit wide interface holding 4 GB of GDDR5 memory. The card has a core clock speed of 1051 MHz core, 1178 MHz boost and 1753 MHz (7012 MHz effective) memory, which gives you 224 GB/s of bandwidth.
The card was run through 3DMark 11 in its Extreme and Performance presets. The card scored X4625 in the extreme test and P11919 in the performance test. That makes the card roughly as fast as the GeForce GTX 780. Keep in mind these a pre-release drivers and most likely a pre-launch qualification sample all together.