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Z77 motherboards from Asus, Gigabyte, and MSI


Next-generation platforms for Intel's next CPU
— 8:58 PM on April 8, 2012

Intel's next-generation processor may be the worst-kept secret in the industry right now. Intel has disclosed quite a bit about Ivy Bridge, and other details have already leaked onto the web, including specifications, benchmark results, and Intel's own marketing materials—yet I've been asked to refrain from mentioning her by name. Instead, she's to be referred to only as Intel's "3rd generation Core processor." And she's not ready yet.

Intel has confirmed that Ivy Bridge's arrival has been delayed to iron out kinks in the 22-nm fabrication process used to make the chip. We may not see notebooks featuring Intel's new hotness until June. Desktop versions of the CPU should be available before then, though, and the 7-series motherboards designed to host them are already for sale. Three of these boards have been toiling away in the Benchmarking Sweatshop for the past week. Today, we're going to take a closer look at what they have in store.

Thanks to their LGA1155 sockets, these 7-series boards are compatible with existing Sandy Bridge CPUs. We've been able to run them through a full range of tests, including some new additions to our peripheral performance suite. With Ivy out of the picture, we have more time to focus her accompanying platform hub and its integrated USB 3.0 controller. We also have more time to spend on the unique attributes of the latest offerings from the big three motherboard makers. Join us as we lift the lid on the Z77 Express chipset and explore the Asus P8Z77-V, Gigabyte Z77X-UD3H, and MSI Z77A-GD65 motherboards.

Introducing the Z77 Express
Intel has a full range of 7-series platform hubs ready for its upcoming 22-nm processor. PC enthusiasts will want to pay the most attention to the Z77 Express, which effectively replaces the Z68 from the 6-series lineup. This flagship platform supports CPU overclocking, SSD caching, QuickSync transcoding, and multi-GPU-friendly PCI Express lane configurations in addition to offering a full array of display outputs for integrated graphics and Lucid's GPU virtualization software. Unlike the Z68 Express, which didn't hit the market until four months after the first wave of Sandy Bridge motherboards, the Z77 has arrived alongside the rest of the 7-series family.

For the most part, the Z77 is very similar to its Z68 predecessor. Its integrated PCI Express 2.0, Serial ATA, Ethernet, and USB 2.0 controllers appear to have been pulled directly from the past generation. Intel says these components will all "behave and perform" similarly to those found in 6-series platforms. There is, however, a new addition: USB 3.0 support.

In addition to a 10-port USB 2.0 controller, the Z77 has a second USB controller that ripples with four SuperSpeed ports. Finally! Intel is pretty much the last major player to adopt USB 3.0 (apart from Apple, of course). Enthusiast-oriented motherboards have sported SuperSpeed ports for years thanks to third-party controllers, and AMD's Llano platform added native support last summer. Unlike some next-gen interfaces, there's a real need for USB 3.0. The second-gen USB spec tops out around 37MB/s under ideal conditions, which is far too slow for modern portable storage devices.


The Z77 block diagram. Source: Intel

Intel's implementation supports the USB Attached SCSI protocol, otherwise known as USAP. This protocol replaces the Bulk-Only Transport (BOT) approach that was designed for USB 1.1 and has persisted ever since. USAP adds command queuing to deal with multiple concurrent I/O requests, and it offers much lower overhead than the BOT protocol. Those attributes should allow storage devices to make the most of the 5Gbps of bandwidth available in the SuperSpeed USB specification.

We'll take an in-depth look at the Z77's USB 3.0 performance in a moment. For now, you should know that USAP support requires compatible devices, which are relatively rare. We hear that Windows 8 will offer native USAP support, so that should encourage device makers to get on board. In the meantime, the Intel controller is backward-compatible with older USB devices. It's been blessed by the USB-IF governing body and by Microsoft's WHQL department.

The rest of the Z77's block diagram is mostly old news, save for next-gen CPU features we aren't supposed to discuss (Ivy Bridge will support PCIe 3.0, for instance) and a few "responsiveness technologies" largely inherited from Intel's mobile division. Rapid Start and Smart Connect fall under that umbrella. The former promises faster system standby and resume times for SSD users, while the latter will periodically wake a sleeping system to synchronize with email and social media services.

While it's tempting to chide Intel for not adding more 6Gbps SATA ports to the Z77, I can understand why the company might be playing it safe with the new platform's primary storage controller. The first batch of Sandy Bridge chipsets was famously sunk by a Serial ATA bug so serious Intel had to halt shipments and re-spin the silicon. Then, this fall, the high-end X79 platform arrived minus the expanded 6Gbps SATA and SAS connectivity many were expecting. The extra storage logic was still there, but Intel couldn't get it working properly in time for Sandy Bridge-E's November debut, so it was disabled in hardware.

The fact is that even most power users won't need more than a couple of 6Gbps SATA ports. (Just because your mechanical hard drive has a 6Gbps interface doesn't mean it needs the extra bandwidth.) Besides, the Z77 and its accompanying CPU have plenty of PCI Express connectivity for more exotic SSDs.

Pick your poison
To get a sense of how the Z77 Express has been implemented by motherboard makers, we've rounded up three models from Asus, Gigabyte, and MSI. Before we dive into more detail with each board, here's a quick look at their particulars:

Asus P8Z77-V Gigabyte Z77X-UD3H MSI Z77A-GD65
DIMM slots 4 DDR3 4 DDR3 4 DDR3
Expansion slots 2 PCIe 3.0 x16
1 PCIe 2.0 x16 (x4)
2 PCIe 2.0 x1
2 PCI
2 PCIe 3.0 x16
1 PCIe 2.0 x16 (x4)
3 PCIe 2.0 x1
1 PCI
2 PCIe 3.0 x16
1 PCIe 3.0 x16 (x4)
4 PCIe 2.0 x1
Gigabit Ethernet Intel 82579V Atheros AR8151 Intel 82579V
Wireless Atheros AR9485 NA NA
Auxiliary USB 3.0 ASMedia ASM1042 VIA VL800 NA
Auxiliary SATA ASMedia ASM1061 Marvell 88SE9172 ASMedia ASM1061
Audio Realtek ALC892 VIA VT2021 Realtek ALC898
FireWire NA NA VIA VT6315N
Warranty Three years Three years Three years
Price $210 $170 $190

Each board has a slightly different slot layout. Only the MSI Z77A-GD65 supports FireWire (and then only via an internal connector), and the Asus P8Z77-V is the lone example with integrated Wi-Fi. All of the boards have at least one auxiliary storage controller, but that role is filled by a number of different chips. We also see some variety on the audio and Gigabit Ethernet fronts.

Motherboard makers have become better at differentiating their products in ways that can't be easily distilled down to a specifications table. Let's take a closer look at each of the boards to see what makes them unique.