Still for the life of me figure out why intel is bothering with this KB-X sku. It offeres no real advantage over the 7700k. At minimum give it quad channel memory or a larger cache like SB-E did at 4 core HEDT.
The 7740k looks on the surface to be almost identical to the 7700k. But, there are important differences.
Likely differences:
1) Faster base clock rate (4.3 GHz vs 4.2 GHz).
2) Systems built around it will be able to handle more power and more heat. Thus it can stay at turbo speed for much longer.
3) No GPU, so all that power can be dedicated to the CPU.
4) So far the leaks show that it is supported with faster memory (DDR4-2666 for the 7740k vs DDR-2400 for the 7700k). Since the 7700k is memory starved, this could help quite a bit.
Possible but unconfirmed differences:
5) Intel could choose to solder the lid on it (I haven't seen if they are going this route or not).
6) Intel could choose to price it right with Ryzen now in the picture. This avoids the issue of investors not liking a chip price cut without a replacement chip. And/or this could be the replacement chip allowing the 7700k to get a nice price cut.
If Intel goes all the way and does all 6 of those, then it will address virtually everything that enthusiasts here complained about the 7700k when it was launched. That would make it a great HEDT entry level chip. If not, at least it isn't worse than the 7700k. I'll take every small bump between ticks/tocks that I can get.