Preface: I do not work for Intel. I'm just an enthusiast and PC technician that has purchased, de-lidded, and overclocked every top model i7 (except the 6700k) since the first chip for which this procedure was available, the 3770k. I currently run a 7700k @ 5.2GHz under a custom water cooling loop. I observe the same behavior the OP and many others are now complaining about, thanks to all the recent coverage in the tech press.
One thing people need to understand here is that transient spikes in temperature which occur only when the processor state goes from idle to "full on" are:
1) not dangerous
2) an expected behavior of modern processors due to their design
What I mean by this is that this observed behavior is a function of Intel's Turbo technology - the ability to quickly change the clock speed (and voltage) of an individual core or multiple cores in order to *respond to a task*.
Now, this ends up creating an issue for users that do not run custom fan profiles in their motherboard's UEFI or via fan controller. Personally, I use a fan controller to set my fan speeds and don't have the fans ramping up/down issue as a result. If your motherboard doesn't provide the granularity you need to create a custom fan profile which prevents your fans from randomly spinning up and down, I would suggest the use of a fan controller such as the NZXT Grid. These are cheap and do the job well.
Hope this helps.
