After being flamed "a bit" by Charlie, among others claiming NVIDIA's roadmap is empty up ahead, it might seem like NVIDIA could use some damage control. It doesn't really because the roadmap is anything but empty. We recently reported about how NVIDIA aims to reclaim the performance leadership from Radeon HD 4870X2, and it might be sooner than we said. NVIDIA is just waiting for AMD to release its beast so it can counter. After that, we should see something new on the horizon.
Details are still hard to come by, but so far we've been hearing a couple of things. Most importantly, NVIDIA seems to have changed its mind regarding DirectX 10.1. The next GPU which should hit the market in late Q4 2008/early Q1 2009 could very well be DX10.1 compliant, and feature GDDR5 memory. This most likely means that NVIDIA will reduce the bus width to 256-bit, because 512-bit and GDDR5 just seems like a huge waste of bandwidth.
We also know that NVIDIA is preparing to launch a 40nm chip as soon as TSMC get its act together and start pushing out half-node wafers. Right now it seems like this will happen in late Q1 2009. This is most likely not the same chip as NVIDIA doesn't do new nodes on the first date with a new high-end card. Things might have changed in the Santa Clara headquarters, we don't know that certain so take it with a pinch of salt.
AMD is expected to hit 40nm in Q1 2009 as well, even less is known about that right now.