According to Xfastest there will be four new processors under the new High-End Desktop (HEDT) banner for Broadwell, which is one more SKU than Haswell-E. One of the more interesting is the Core i7-6950X which is a 10-core CPU with Hyper Threading. This gives it 20 threads to play with and 25MB of L3 cache.
The downside is that the CPU will be a little slow. It will run at just 3.0GHz and will be useless for software that is not properly tuned to take full advantage of large core counts and threads.
In some cases it would be behind the Core i7-6700K which is a quad-core Skylake processor clocked at 4GHz (base) to 4.2GHz (Turbo). The Core i7-6950X still has more L3 cache, but for tasks where raw clockspeed reigns supreme, the 3GHz chip might even lose out to the Core i7-4790K, a Devil’s Canyon part clocked at 4GHz to 4.4GHz.
If clock speed is important, Intel will release two faster-clocked six-core Broadwell-E processors and an eight-core CPU that strikes a balance between clockspeed and core count. The specs that Xfastest found show:
Intel Core i7-6950X: 10 cores, 20 threads, 25MB L3 cache, 3.0GHz
Intel Core i7-6900K: 8 cores, 16 threads, 20MB L3 cache, 3.3GHz
Intel Core i7-6850K: 6 cores, 12 threads, 15MB L3 cache, 3.6GHz
Intel Core i7-6800K: 6 cores, 12 threads, 15MB L3 cache, 3.4GHz
All of these processors will have a Turbo clockspeed, though information about the specific clockspeeds is unavailable. All socket LGA2011-v3 CPUs should be compatible with existing X99 Express chipset motherboards.