INtel i7 4790k vs intel i5 4690k

Solution
The 4790K has a higher stock clock of 4.0Ghz even though the 4690K can be overclocked to match it. The main difference is that the i7 uses hyperthreading technology, I suggest you look it up. It's helpful for video encoding, photoshop, and such programs but not for gaming.
The 4790K has a higher stock clock of 4.0Ghz even though the 4690K can be overclocked to match it. The main difference is that the i7 uses hyperthreading technology, I suggest you look it up. It's helpful for video encoding, photoshop, and such programs but not for gaming.
 
Solution
Hyperthreading is a bit overrated by people who don't understand what it does. It doesn't add more cores, it arranges threads for better efficiency in an attempt to keep the actual cores (4 in the case of the 4790k) busy. It's rarely a 30% performance increase. Just like intel says, it depends on the application and how it's designed. Some make use of it, others don't, in some cases it can hurt performance (things like vmware virtual machines).

https://software.intel.com/en-us/articles/performance-insights-to-intel-hyper-threading-technology

https://pubs.vmware.com/vsphere-4-esx-vcenter/index.jsp?topic=/com.vmware.vsphere.resourcemanagement.doc_41/managing_cpu_resources/c_hyperthreading.html

Some tests done with cpu's where the ht was enabled and disabled to show the actual performance gained by using hyperthreading.
http://www.extremetech.com/computing/133121-maximized-performance-comparing-the-effects-of-hyper-threading-software-updates

Even in cinebench, the performance increase in a program that utilizes hyperthreading well gained only an 11% increase in performance. 46s to render the image with ht disabled, 41s to render the image with ht enabled. Not as huge of a difference as people seem to think, it's still just quad core same as the i5's. All hyperthreading does is allows the cores to stay busy a bit longer. Not quite the 30% increase a lot of people think and it's not a guarantee. By intel's own admission it's software dependent and may or may not provide enhancement. It's not something you can count on.

https://www.youtube.com/watch?v=EMbYd4LEggo

Don't get me wrong, the i7's are definitely better cpu's and they're a tier up from the i5's. However being there are different versions of the i7, it's not quite as huge of a leap when comparing an i5 (all desktop i5's are quad core) to a lower end quad core i7 (as opposed to the higher performing 6 and 8 core i7's). Where xeon's are equated to an i7 with slower locked clock speeds and no igpu, the same could be said for the i5. In the case of the 4790k, it's just a slightly higher factory clocked i5 with ht enabled. Since i5's have a 'k' version (unlike xeons for the 1150), they can easily be overclocked to match the speeds of an i7.
 

There are very few examples of applications that perform worse with hyper-threading. These are compatibility issues in older software like SQL Server 2000.
A virtual environment is always going to benefit from hyper-threading if you compare a 4 core processor to a 4 core processor with hyper-treading. The VMWare page you linked is from a very old version of VMWare. The only way you are going to run into problems is in allocating resources assuming each logical core is a full physical core, which of course with hyper-threading it is not.
As mentioned previously, games benefit very little from HT support in a quad core processor. It does however help in dual core processors.
30% is a good rule of thumb for most applications providing the threading of these applications could otherwise make use of the extra cores.