Intel Z77: Specifications
Chipsets have become very simple in design after memory and PCI controllers moved into CPUs. Having previously consisted of two pieces, a North Bridge and a South Bridge, a modern chipset is a single-piece thing responsible for I/O interfaces. It doesn’t influence the performance or capabilities of a platform much, but affects the design of mainboards and the choice of their additional onboard controllers. So, we can hardly expect the new chipset to greatly improve the consumer properties of computer systems. In fact, Z77-based mainboards are very similar to those with the older Z68. When developing its new chipset, Intel just tried to meet the requests of mainboard makers who wanted to have a richer selection of I/O interface within the single basic component.
There were two main shortcomings about Intel's previous flagship chipset Z68. It didn’t have USB 3.0 and it only offered two SATA 6 Gbit/s ports. Adding more ports of these types into chipsets for the LGA 1155 platform is the obvious way to improve them. However, Intel had had some reliability issues with new interfaces in its 6 series chipsets and now takes a very conservative approach to this. On one hand, the new chipsets have finally acquired the modern USB 3.0 interface but, on the other hand, the maximum number of such ports is limited to four whereas the SATA interface hasn’t been upgraded at all. There are still only two SATA 6 Gbit/s ports available. So, it's clear that the evolution of desktop platforms for Sandy Bridge and Ivy Bridge processors won't be rapid until the next “tock” in the cycle.
With these things forming the background, Intel can hardly be expected to take big steps forward like introducing the high-speed Thunderbird interface in its chipsets. Being one of the key developers and supporters of that technology, Intel has left for Apple to take any real measures to promote it. The Z77 has no integrated Thunderbird controllers, yet the interface isn't altogether forgotten. It can be implemented in new mainboards via an external controller, connected through four PCI Express lanes.
There are two key facts about the new chipsets. First, Intel’s 7 series chipsets do not support the PCI bus. Although it can be implemented on a mainboard by means of additional converter chips, we’d recommend you to get used to the idea that PCI is no more. The PCI bus not provided for in the reference design, there is going to be but a limited number of new mainboards with PCI slots.
The other fact is the simplification of Intel’s nomenclature. They had as many as three product types with the 6 series chipsets for consumers (we don't count business-targeted products in here): H for basic integrated systems, P for systems with discrete graphics, and Z for the mix of both. However, users didn't seem to need so much choice. Therefore the 7 series includes only two basic variants: H for basic systems and Z for overclocker-friendly systems. There won't be chipsets that cut the CPU-integrated graphics core off, so every mainboard with a 7 series chipset will be able to utilize the graphics capabilities of LGA1155 CPUs.
By the way, Intel’s integrated graphics has been getting rid of the lackluster reputation it has earned over years. Right now, its performance and functionality is quite sufficient for a large range of applications. Financed by Intel, Lucid Logix has also contributed to this with its set of technologies for enabling the integrated graphics along with a discrete graphics card.
Moreover, the Ivy Bridge processors are going to feature a more advanced graphics core than their Sandy Bridge predecessors, both in performance and in functionality. It will support up to three display devices simultaneously when used together with a 7 series chipset.
This seems to be the biggest difference between mainboards with 6 and 7 series chipsets, actually. The rest of the differences can be made up for by additional controllers. As for CPU support, the older 6 series mainboards are fully compatible with the Ivy Bridge (after a BIOS update) whereas the new mainboards are going to work with both Ivy Bridge and Sandy Bridge CPUs. There are no significant differences even when it comes to overclocking.
Overclockers could be disappointed with the LGA1155 platform which didn't let them overclock CPUs by increasing the base clock rate. The 6 series chipsets had an integrated clock generator that was used for clocking both the CPU and chipset components. As a result, increasing the base clock by 5-7% rendered the system inoperable due to the chipset’s controllers.
Unfortunately, the 7 series doesn’t change anything in this respect. Positioning LGA2011 as the enthusiast-targeted platform, Intel doesn’t want to implement the same overclocking capabilities on the LGA1155 platform. The new 7 series chipsets let you overclock Sandy Bridge and Ivy Bridge CPUs in the same way as before: by increasing their frequency multiplier.
So, if the Z77 is a step forward from the Z68, that’s not a big step at all. The Z77 flowchart looks almost identical to the Z68 one:
The following table summarizes the key differences of the 7 series chipsets from their predecessors:
Besides the Z77, the 7 series includes the slightly less advanced Z75 and H77 as well as a few B and Q chipsets which are meant for corporate users and are not discussed here. The Z75 is a Z77 with limited capabilities in terms of splitting up the CPU-integrated PCI Express lanes. The H77 is an even simpler version that doesn’t support SLI/CrossFireX configurations and lacks any CPU overclocking features.
These chipset modifications are compared in the next table:
The positioning of the Z77, Z75 and H77 should be clear enough. The senior and most expensive chipset is going to be installed on mainboards for DIY systems. The Z75, which doesn't support SSD caching among other things, is only going to be used in cheap products, especially as it can help save a hefty $8 for mainboard makers. Lacking any CPU overclocking features, the H77 is likely to be found in compact mainboards for small computers where overclocking and SLI/CrossFireX support aren’t relevant.