Intel Kaby Lake Chipset Updates: Z270, H270, B250

The 200-series push for Kaby Lake chipsets increases HSIO lane availability to 30 total lanes on both the H270 and Z270 chipsets, marking the first time that Z and H models are at parity for total high-speed I/O availability. This doesn’t change the fact that, as always, Z allows for overclocking where H does not – but the difference caused by HSIO lane differences is gone.

Z270 supports a total of 24 PCI-e 3.0 lanes (to H270’s 20), in addition to the lanes peeled off of the CPU for graphics devices. As a reminder, chipset PCI-e lanes are not treated in the same way as CPU PCI-e lanes. Aside from originating from a different physical location on the motherboard, the chipset lanes also can only be peeled-off in groups of 4 (x4), so multi-GPU configurations relying on the chipset for a third or fourth GPU will operate only in x4.

Instead, these lanes are intended to be used for other high-speed devices that operate on the PCI-e bus, like M.2 PCI-e SSDs, NVMe drives, or AICs in the lower PCI-e slots.

Here’s a table to help clarify hard numbers versus the 100-series (6th Gen) chipsets:

Intel Z270, H270, & B250 Chipset Differences (Kaby Lake)

As for the total HSIO lane count, as with previous generations, this is something that motherboard manufacturers have some hand in allocating. A board designer could choose to allocate most of the lanes to SATA, or to additional Gigabit Ethernet ports, or additional USB3.x ports – these are high-speed I/O interfaces and protocols, and these are what receive the lane assignment from the PCH.

Let’s take a look at the Z270 and H270 block diagrams for a more visual recap:

Intel Z270 Block Diagram & Specs

And to compare versus Z170:

Intel Z170 Block Diagram & Chipset Specs

And now, H270:

Intel H270 Block Diagram Chipset Specs

PCI-e lane & HSIO lane count is the primary difference between these two, alongside the usual multi-GPU and overclocking limitations of non-Z chipsets. H270 is only meant to support a single 1x 16 PCI-e GPU, to Z270’s dual-GPU readiness (or triple, if willing to drop to x4 on two slots).

You should avoid H270 if planning the following:

• Any amount of overclocking (instantly forces you to Z)
• Multiple video cards
• Active utilization of so many chipset PCI-e lanes that you’ll need four more (e.g. heavy reliance on PCI-e SSDs or AIC devices).

Let’s pull up B250 next:

Intel B250 Block Diagram Chipset Specs

This is where things change substantially. B250 also supports only a single GPU (1x 16), but loses four USB3.0 ports, two USB2.0 ports, and x12 PCI-e 3.0 lanes (versus Z270). This would be a fine platform for budget and non-enthusiast system builds, assuming motherboard prices fall in step with the lower SKU chipset.

Continue to Page 3 for CPU testing methodology or Page 4 for testing.