There is only one new product in the Core i7 series:
The Core i7-4790 steps up the clock rate of the senior LGA1150 processor series by 100 MHz, being faster than the overclocker-friendly i7-4770K and the regular i7-4771. Otherwise, it is a typical Haswell-based Core i7 with four cores, Hyper-Threading, and a large 8MB L3 cache. The integrated graphics core GT2 incorporates 20 execution devices. Thanks to Turbo Boost 2.0, the Core i7-4790 works at 3.8 GHz most of the time.
The processor supports the full set of security technologies including vPro, TXT and VT-d. Thus, the Core i7-4790 is the new flagship for the LGA1150 platform but without support for overclocking.
The Core i5 series includes three Haswell Refresh products:
Their clock rates are a mere 100 MHz higher compared to their predecessors, but that’s enough for the Core i5-4690 to surpass the Core i5-4670K and become the fastest model in the Core i5 series. The other models fill in previously unoccupied frequency slots. The rest of their specs have not changed. Hyper-Threading is not supported by any Core i5. The L3 cache is 6 megabytes large and the graphics core is of the GT2 class.
The junior model i5-4460 is special as it doesn’t support vPro and TXT. It can’t work with transactional memory, either. With Turbo Boost 2.0, the typical clock rate of the i5-4690, i5-4590 and i5-4460 is 3.7, 3.5 and 3.2 GHz, respectively.
There are three Haswell Refresh products in the Core i3 series:
Again, the clock rates are increased by 100 MHz while the rest of the specs are the same as before. Unlike the other series, the Core i3 includes only dual-core processors but with Hyper-Threading support. Thanks to that, their TDP is specified at 54 rather than 84 watts. There were no free frequency slots in the Core i3 series when the Haswell Refresh models were announced, so the Core i3-4350 has exactly the same specs as the Core i3-4340 but comes at a lower price.
The L3 cache is 4 megabytes large in the i3-4360 and i3-4350 models. The i3-4150 has 3 megabytes of L3 cache memory. Besides, the junior model has a weaker graphic core. Although formally classified as GT2, the i3-4150’s graphics has 16 instead of 20 execution devices.
The LGA1150 Haswell Refresh processors don’t have any special requirements concerning the mainboard. Although their release coincides with the transition to the new 9 series chipsets (Z97 and H97), all of the new CPUs are compatible with LGA1150 mainboards based on Intel’s 8 series chipsets. For the processor to be correctly identified by the mainboard you only need to update the latter’s BIOS.
As for overclocking capabilities, the currently available Haswell Refresh CPUs have none. You can’t increase their clock rate above the default level by changing their frequency multiplier. The base clock rate can be increased to 105-110 MHz but that can hardly be called serious overclocking. On the other hand, these processors allow overclocking system memory up to DDR3-2400.