X48 Motherboard Comparison

Gigabyte GA-X48-DQ6

Gigabyte's choice of DDR2 for its X48-DQ6 certainly surprised a few industry insiders, as Intel's highest-end chipset targets an upscale "money is no object" market where DDR3 is the expected standard. Intel didn't even bother listing "DDR2" support in its X48 Express function diagram, but the move was easy for Gigabyte, as the new model uses the same circuit board as its top-overclocking X38-DQ6 predecessor.

In fact, every single component other than the MCH is the same, and since the X48 Express is nothing more than an X38 Express with a higher validated stable bus speed, the only difference buyers can hope to see is better overclocking potential. The X48 Express might be a step up from the X38, but it's evident that Gigabyte was comfortable enough in the quality of the earlier components that it didn't see any need for alterations.

There are lots of praiseworthy aspects of the X48-DQ6 layout, such as slot positioning. Gigabyte puts its uppermost PCI Express 2.0 (x16) slot in the second position from the top, to make additional room for the cards beneath, compared to the Asus design. The second x16 slot is three positions below the top x16 slot and three positions above the motherboard's bottom edge, providing ample room for graphics coolers, while leaving extra space for air circulation. Three PCI Express x1 and two PCI slots make up the remainder, with DIMM placement limiting the top x1 slot's card length to 6.75 inches (171 mm).

In order to achieve the better slot layout, Gigabyte placed its DDR2-SDRAM slots closer to the X48-DQ6's top edge compared to the Asus design, which puts the memory a little further off-center from the northbridge. Gigabyte also placed the X48 Express northbridge a little higher to compensate, resulting in the CPU socket being closer to the top edge of the board. While the X48-DQ6 provides ample room for CPU cooler installation, the design eliminated any possibility of surrounding the socket with an extended heatpipe assembly. Thus, a tiny stand-alone sink cools the transistors of the final two CPU voltage regulator "phases".

The only problem we perceive with so many components moved "northward" towards traditional positions is that some oversized CPU coolers will extend past the top edge of the board. Users of "short" mid-tower cases might find that the CPU cooler gets in the way of mounting a power supply. This will probably only affect a small number of users, as traditional 17" tall mid-towers that cram the power supply right next to the motherboard's top edge are no longer popular in the enthusiast market for which the X48-DQ6 is intended.

All eight Serial ATA connectors face outwards from the motherboard's surface for easy cabling, even in cases that have a drive bay immediately adjacent to their front edges. The ports are positioned "three slots" beneath each PCI Express x16 interface, to avoid interfering with long double-slot graphics coolers. Gigabyte finds room where Asus didn't because the GA-X48-DQ6 doesn't have a third graphics card slot, and the two it does have are positioned farther apart.

Both PCI Express x16 slots support PCI Express 2.0 mode, which doubles available bandwidth compared to previous versions.

The Ultra ATA connector faces towards the GA-X48-DQ6's front edge, but clearing the hard drive cage of tight cases shouldn't be a major issue, since appropriate cables always use ninety-degree ends. Easier cable routing to upper-bay-mounted optical drives may have been possible had Gigabyte placed the connector further up the front edge, but the board appears to lack the needed space to round connector traces in that direction. At least the Ultra ATA connector is close to the Gigabyte SATA2 controller that serves it, potentially benefiting the connector with reduced noise.

Gigabyte continues to provide support for antiquated serial and parallel printer ports by placing break-out connectors internally along the X48-DQ6's bottom edge (beneath the lowest PCI slot). Also found here is a header for an optional TPM module and S/P-DIF Input connector. Though the parallel, serial, and S/P-DIF Input options are all presented, Gigabyte leaves it to buyers to find the needed "break-out" cables to use them.

As with the Asus model in this comparison, the GA-X48-DQ6 provides only two internal USB 2.0 connectors (four ports total), which means that anyone with four front panel USB ports will need to search earnestly if they want to find a place to plug in additional USB bay devices. Gigabyte's reasons for this shortage differ from those of Asus, in that the X48-DQ6 provides additional ports to the rear panel, while Asus has simply "used up" its connectors for internal devices. A note to manufacturers: motherboard reviews could be a good place to advertise internal PCI Express 2.0 hubs, if such internal devices exist (though we haven't seen any).

Anyone not using Windows Vista will be pleased to find a floppy connector located near the top of the X38-DQ6's front edge, for easy cabling to the floppy drive required for loading Windows XP RAID or AHCI drivers.

While various manufacturers debate over added features versus better layout, Gigabyte does have one distinct layout advantage which isn't affected by other features: its front-panel audio header is located directly forward of its rear-panel audio jacks. With so many case manufacturers placing front-panel jacks near the top of their towers, this design is a boon to cable management, and could be critical with a few cases that have cables that might otherwise be too short.

Gigabyte's version of the JMicron JMB36x controller series uses a PCI Express x1 interface to deliver up to 250 MB/s of data to and from connected drives, bi-directionally (500 MB/s combined). Likewise, PCI Express provides both Realtek RTL8111B Gigabit Ethernet controllers with 2.5 times the needed bandwidth, and the excessive amount of bandwidth available from PCIe makes us question why companies simply don't use two-port Gigabit controllers on a single PCI Express lane.

Having eight USB 2.0 ports on the back panel is nice, but most users find these difficult to reach once the system has been placed onto or under a desk. An additional internal USB header might have been more useful.

Gigabyte retains both its PS/2 keyboard and mouse ports, knowing that some users still prefer this interface for gaming mice. Other rear panel connectors include optical and coaxial digital audio outputs, full-sized and miniature IEEE-1394 FireWire ports, dual Gigabit ports, and six analog audio jacks.

Gamers who don't use discrete soundcards will note that four of the analog audio jacks are normally required for 7.1 game surround, since most onboard audio codecs don't support real-time signal combining to a single digital stream. Gigabyte went the extra mile here by providing DTS Connect, which requires only a DTS Interactive enabled receiver or integrated speaker system, in addition to a coaxial or optical digital audio cable, to play live multi-channel streams through one of the motherboard's digital outputs.

Rated at 106db signal-to-noise ratio for 7.1 channel analog output, the Realtek ALC889A is actually a 10-channel solution because the front panel audio jacks can be configured separately from the rear channels. This prevents background audio from interfering with the use of headsets.