Rumors regarding the next generation of 28nm graphics cards from AMD and Nvidia continue to arrive at a frantic pace and the latest to emerge cover Nvidia’s upcoming GK104 core that is presumably expected to arrive in Q1 2012.

The GPU, which will be built using TSMC’s 28nm process technology, has fallen under the scrutiny of the 3DCenter website which has come out with some preliminary specs for this graphics core.

According to this publication, the GK104 will feature between 640 and 768 streaming processors, 80 to 96 TMUs and either a 256-bit or a 384-bit memory interface linked to GDDR5 memory.

The graphics cards based on this GPU will come as replacements for the models in the popular GeForce GTX 560 product family, with performance being expected to slightly surpass that of the current GeForce GTX 580.

3DCenter’s speculations also note that in order to prepare the GK104 for a Q1 2012 launch, Nvidia had to settle with a hybrid between Fermi and Kepler, while the first parts based entirely on the new architecture won’t arrive until the introduction of the GK100 GPU.

Right now, it’s hard to tell how much of the info provided by 3DCenter is true since some of it comes to contradict an Nvidia roadmap that was leaked by 4Gamers a short while ago.

Furthermore, an Nvidia rep has said recently that the company’s Kepler GPUs are on track and that the Santa Clara CPU maker has already entered into the possession of the first chip samples based on this architecture.

“We are on track with our Kepler roadmap. We have 28nm silicon in house now. Our transition to 28nm is going better than 40nm, and yields are better than our original plan,” said Igor Stanek, Senior Product PR Manager at Nvidia.