This is the same way that AMD’s GPUs have operated for years and is another example of the two companies moving in the same direction when it comes to GPU design. This means the whole GPU, stream processors and all, runs at a nippy base clock of 1,006MHz. Sadly, that’s not quite the case, as Nvidia has chosen to scrap the separate shader clock, long a defining feature of its GPUs. With so many more stream processors than its predecessor and an otherwise similar GPU layout, you’d be forgiven for expecting a quite extraordinary threefold increase in performance. Think of it as a GPU-take on Intel's Turbo Boost technology, which works in conjunction with SpeedStep to produce the best performance-per-Watt for CPUs that feature it. The scheduling functions themselves have also been redesigned and greatly simplified with a greater focus on power efficiency. The GTX 680 hence reshapes the definition of fixed load clock speed, with dynamic clock speeds. This doubles the GPU’s instruction per clock rate in comparison to Fermi, necessary when there are so many more stream processors to address.
The number of Warp Schedulers (the part that assigns render threads from the Gigathread engine to individual SMs) has doubled to four per SM (although the total number on the GPU remains 32) and each is now able to dispatch two instructions per clock thanks to a pair of instruction dispatch units for every Warp Scheduler. The Nvidia GeForce GTX 680 contains four GPCs with a total of eight SMXs, 1536 CUDA cores, eight geometry units, four raster units, 128 texture units, and 32 ROP units. This huge increase in stream processor count to 1,536 for the whole GPU (tripled in comparison to the GTX 580 1.5GB’s 512 stream processors) has required some extra additions to each SM. The result is a peak of 192.26GB/s of memory bandwidth. We told them differently, so let's show you the latest GTX 680 from them. GeForce GTX 680 cards will have 2GB of GDDR5 memory, linked to the GPU over a 256-bit interface, with an impressive 6008MHz effective data rate. The new SMs, dubbed SMX (presumably Nvidia is competing with AMD’s ‘GCN’ for silliest GPU lingo 2012) have been completely redesigned, and now boast a whopping 192 stream processors each, as opposed to the 32 stream processors found in each SM with Fermi. NVIDIA GEFORCE GTX 680 (Kepler) 2GB Reference Card Video Card Review As far as NVIDIA knew we couldn't get a GTX 680. Each GPC still contains its own raster engine, but it’s within the SM that the real changes have been made. With the card being part of the Lightning series, though, were more interested in the overclocking side of things and looking above you can see we pushed the core to 1200MHz or 1265MHz via Boost. Click to enlarge - The Kepler Architecture and a side-by-side comparison of Kepler's SMX and Fermi's SMĪs with Fermi, the GPU is split into four separate graphics processor clusters (GPCs), but each is now comprised of just a pair of SMs rather than four SMs apiece, in a similar fashion to the GTX 560 Ti 1GB's GF114 GPU.