X48 heavyweights go head to head

Although Intel’s processors and chipsets have long been embraced by PC enthusiasts, the company’s motherboards have largely been ignored. Years ago, it was easy to see why. Intel motherboards didn’t come with the tweaking and overclocking options that we crave, and that was understandable, since we never really expected Intel to endorse overclocking. However, times have changed, and so has Intel’s tune. The firm now has several products targeted specifically at enthusiasts, including the new DX48BT2 “Bonetrail 2” motherboard that comes loaded with many of the features we’d expect from a modern, high-end mobo.

Based on Intel’s flagship X48 Express chipset, Bonetrail’s second coming faces stiff competition from Taiwanese mobo makers with far more street cred in the enthusiast space—credibility that, for the likes of Asus, is well deserved. Asus one of the biggest players in the motherboard market, and it’s been catering to enthusiasts for as long as I can remember. Asus has embraced the X48 Express, as well, most recently with its Rampage Formula motherboard.

The Rampage Formula and DX48BT2 effectively target the same market, albeit with one DDR2 memory and the other with DDR3. For once, however, Intel is the underdog. Read on to see if the processor giant can beat Asus at its own game.

Intel’s DX48BT2 motherboard
Designed for enthusiasts, seriously

Intel introduced its first Bonetrail board, the DX38BT, last year with its then-flagship X38 Express chipset. The X38 has since been replaced by the X48 Express to accommodate the Core 2 Extreme QX9770’s 1600MHz front-side bus, bringing with it a Bonetrail redux in the DX48BT2. We really wish Intel had stuck with the Bonetrail code-name here; DX48BT2 doesn’t exactly roll off your tongue, although we can at least take some solace in the fact that the board avoids banal Extreme Edition branding. If you look closely, though, the BT2’s Bonetrail roots shine through in the form of a couple of stylized skull logos emblazoned on the board.

As if the skull logo weren’t tough enough, the DX48BT2 comes dressed in black and blue, like a tattooed biker in denim and leather.

In theory, Intel has an advantage over competing motherboard makers because it engineered the X48 Express chipset that lies at the DX48BT2’s core. Given intimate knowledge of the chipset and its associated quirks, Intel’s motherboard designers should be able to exploit the X48’s potential fully. There’s more to a good motherboard than pushing the chipset to its limits, though, starting with how all of the various slots, components, and connectors are laid out on the board.

The DX48BT2’s layout begins well enough, with power connectors located along the edges of the board where their associated cabling won’t interfere with airflow around the CPU socket. Intel also does well to place the board’s single IDE port—powered by an auxiliary Marvell storage controller due to the ICH9R’s lack of legacy ATA support—near the top edge where it will be close to the 5.25″ drives bays of most enclosures.

Not that Intel’s stock processor coolers need it, but there’s also plenty of room around the CPU socket for larger heatsinks. The BT2 can easily accommodate Scythe’s massive Ninja heatsink, and since there’s so much room around the socket, installation is a snap. That’s more than can be said for some enthusiast boards, which, if they do provide clearance for larger heatsinks, often leave little room to access the retention tabs that hold coolers in place.

Always the, ahem, rebellious non-conformist, Intel bucks the recent trend toward intricate networks of heatpipe-linked chipset and voltage circuitry coolers in favor of simple passive heatsinks. The modest array of heatsinks makes the Bonetrail board look a little sedate next to its competition, but if anyone knows how much cooling the X48 Express north bridge requires, it should be Intel.

The DX48BT2’s ICH9R south bridge chip gets away with a low-profile passive heatsink that leaves plenty of room for longer graphics cards. Unfortunately, though, double-wide graphics cards have the potential to block access to the board’s Serial ATA ports. The ports are smartly placed out of the way along the edge of the board, and they’re arranged in pairs presumably to provide additional clearance. However, the spacing isn’t quite right, which is problematic if you plan on running a double-wide card longer than nine inches.

If you’re willing to sacrifice SATA ports, you can actually run up to three double-wide graphics cards in the DX48BT2. Thanks to its X48 Express north bridge, the board has 32 lanes of PCI Express 2.0 connectivity split evenly between its top two PCIe slots (blue in the picture above). The third physical PCIe x16 slot gets four lanes of gen-one PCIe connectivity via the ICH9R south bridge chip. This slot could prove useful if you’re looking to run a three-way CrossFire configuration.

Despite the three PCIe x16 slots, the BT2 is actually a little short on expansion capacity. A couple of PCI slots are provided, but that only brings the slot count up to five—two fewer than other X48-based designs. Fortunately, the backward compatibility provisions built into the PCI Express spec will allow the board’s x16 slots to work with PCIe x8, x4, and x1 cards.

Intel populates the DX48BT2’s port cluster with a decent array of connectivity options, including a couple of External Serial ATA ports powered by the same Marvell controller responsible for the board’s IDE port. A TOS-Link digital S/PDIF audio output is also provided, alongside a full complement of analog audio ports backed by an eight-channel Sigmatel 9274D HD audio codec. We don’t see Sigmatel codec chips used much, but the BT2’s implementation was apparently good enough to earn the board a Dolby Home Theater certification.

Eight USB ports fill out the cluster, which is conspicuously devoid of PS/2, serial, and parallel connectivity. We can live without the legacy ports—it’s 2008, folks, time to move on—but Intel would have been wise to offer a little something extra in their place. The DX48BT2 could do with a couple of additional USB ports (onboard headers are available for four more ports), a coaxial S/PDIF output, and a digital S/PDIF input port.

Asus’ Formula Rampage motherboard
X48 goes old-school with DDR2

A testament to its popularity among high-end motherboard buyers (and its ability to produce multiple model variations based on the same basic board foundation), Asus offers no fewer than ten different motherboards based on the X38 Express chipset. The company’s X48 Express lineup is already up to three models, with the Rampage Formula potentially the most attractive to enthusiasts because of its support for DDR2 rather than DDR3 memory.

The X48 Express’ memory controller is flexible enough to handle either memory type, but most of the boards released to date—including Intel’s DX48BT2—have opted to support DDR3, despite the huge price premium it commands over DDR2 modules. If you can afford to drop between $250 and $300 on a high-end motherboard, value probably isn’t your primary concern. However, it’s hard to ignore the fact that DDR3 modules typically cost three to four times that of comparable DDR2 DIMMs.

Of course, DIMM slots are perhaps the least interesting element of the Rampage Formula. This is a high-end Asus motherboard we’re talking about, and as such, it’s loaded with all sorts of interesting features and extras. Even with those extra goodies, Asus manages to lay things out intelligently on the board, avoiding major clearance problems while covering the Rampage with close to a metric ton of copper.

Most of that copper can be found around the CPU socket in an ornate array of heatsinks that cover the north bridge chip and voltage regulation circuitry. Some aluminum fins are thrown in for good measure, serving as a mounting point for the board’s auxiliary cooling fan. The fan is only recommended if you’re overclocking or run a water- or passively-cooled system with little ambient airflow, and we didn’t encounter any problems running our board without the fan, even when overclocking.

With so much metal walling in the socket, one might expect the Rampage Formula to sacrifice compatibility with larger aftermarket coolers, but the heatsinks are relatively short, providing just enough clearance for the Scythe Ninja cooler we tried to shoehorn into crowded socket real estate. Installing the Ninja is another matter, though. The Rampage’s heatsink array may be a low-profile design, but it can make getting at a cooler’s retention tabs a little tricky.

The Rampage’s cooler network snakes a heatpipe down to a low-profile heatsink on the ICH9R south bridge. Clearance for gargantuan graphics cards isn’t a problem here thanks to Asus’ use of edge-mounted IDE and SATA ports. Sideways Serial ATA ports don’t always play nicely with extremely tight enclosures that leave little room around the edges of the motherboard, but we’re willing to live with the trade-off for the additional graphics card clearance.

Over on the other side of the board, Asus stacks six expansion slots. The top slot is reserved for an audio riser card that we’ll detail in a moment, so it doesn’t really count toward the total.

Apart from the riser expansion slot, the Rampage features pairs of PCI, PCIe x1, and PCIe x16 slots. These are arranged to ensure that double-wide CrossFire configs will leave users access to at least one PCI slot and PCIe x1 slot. However, expansion cards longer than about six and three-quarters inches won’t fit in the top PCI slot due to the proximity of the Rampage’s DIMM slots.

Like Intel’s Bonetrail board, the Rampage Formula lacks serial and parallel ports. It’s also missing a PS/2 mouse port, but retains a PS/2 keyboard port, presumably for those attached to vintage clickety-clack buck spring keyboards that don’t have USB interfaces.

External Serial ATA connectivity is missing from the port cluster, which is an odd omission for a high-end motherboard. However, you do get a handy CMOS reset button that’s perfect for trial-and-error overclocking. Asus also throws in six USB ports, Firewire, and two flavors of digital S/PDIF audio output.

The rest of the board’s audio ports can be found on a SupremeFX II riser card that houses an Analog Devices ADI 1988B codec chip. In theory, the riser card and its shielding should help to isolate the codec and analog outputs from board-level noise that can degrade output quality. We’ll have to see if our analog audio signal quality tests bear that out.

Extras are a staple of high-end Asus motherboards, and the Rampage Formula is no exception. The board comes bundled with an auxiliary cooling fan and ingenious little front-panel connector blocks that make enclosure wiring a whole lot easier. More interesting, however, is an external POST code display that takes the beep code deciphering out of troubleshooting boot problems. The LCD display isn’t nearly as swanky as the SideShow module Asus has experimented with on some motherboards, but it’s a neat little extra. A recessed CMOS reset button, even if it required a pin to activate, would make this external display even better. After all, if you encounter a POST code error, chances are you’re going to have to reset the CMOS to fix it.

Asus also bundles some software with the Rampage Formula, and it’s something you might actually want: a copy of S.T.A.L.K.E.R.: Shadow of Chernobyl.

BIOS options and tweaking software
For a motherboard to resonate with enthusiasts, its BIOS must be packed with enough overclocking and tweaking options to push a system to its limits—and then some. We expected the Rampage Formula to do well here—I can’t remember ever using an Asus motherboard that wasn’t loaded with overclocking and tweaking options—and were pleasantly surprised to find that Intel did a pretty good job with the BIOS on the DX48BT2, as well.

If you’re looking to overclock a Core 2 processor, both of these boards have plenty of front-side bus headroom. The Rampage Formula’s FSB can be cranked 300MHz higher than that of the Bonetrail board, but that should only affect the most extreme of overclocking attempts. Unless you’re packing liquid nitrogen, chances are the DX48BT2’s 500MHz front-side bus ceiling will be plenty.

Of course, if you’re overclocking the front-side bus, you’ll need to keep your system’s memory in check. Both boards offer a wealth of options here, but Asus makes selecting a target memory bus speed much easier. The DX48BT2’s BIOS requires that you set reference and target memory clocks, and for the uninitiated, it isn’t exactly clear how the two work together. We also found that target memory speeds didn’t always work properly with a 400MHz reference clock.

Overclocking, Intel style

On the voltage front, both boards offer plenty of tweaking options, including control over GTL reference values that seem to be quite important if you want to really push quad-core chips. As one might expect, the Rampage yields access to a few more system voltages than the Bonetrail and allows for greater overvolting. Still, the variety and granularity of the voltage tweaking options provided by the DX48BT2 should be more than adequate for conventional overclocking.

When comparing DRAM voltages and bus speeds between the boards, keep in mind that the BT2 uses DDR3 while the Rampage is equipped for DDR2. DDR3 memory runs at higher clock speeds and has a lower default voltage than DDR2.

Overclocking made easier by Asus

Speaking of memory, we should note that both boards provide access to all sorts of timings. The Rampage offers more tweaking options here, but even seasoned enthusiasts probably won’t go beyond the array of timings available for adjustment on the Intel board. That is, of course, unless you know what all of the more obscure memory timings actually do. I haven’t a clue.

Asus offers fan speed control that you can actually control, sort of

BIOS-level fan speed control has become increasingly important for enthusiasts looking to bask in the glory of a silent system, and both the Rampage and Bonetrail boards offer temperature-based fan speed control for their processor and system fan headers. There isn’t much you can do on the Intel board other than simply enabling or disabling temperature-based fan speed control. The Rampage allows one to choose between a few different processor fan speed profiles. Temperature targets and fan ratio (as a percentage of maximum fan speed) control are available for two system fan headers—a feature we’d like to see available for the processor fan. The Asus board’s third system fan header gets speed control, too, but only a manual ratio setting without any temperature-based automatic control.

If you’re not comfortable poking around in a BIOS menu, you probably shouldn’t be overclocking or tweaking system settings. However, if you must, both Asus and Intel offer Windows-based tweaking and overclocking software.

Intel’s Desktop Control Center is still in beta. Although it’s not bundled with the DX48BT2, it’s a free download and a surprisingly solid application. The interface could use some slimming down (the individual tweaking panels under the main interface in the picture above can be closed individually), but overall, it looks much less offensive than the tweaking apps we’re used to seeing from Taiwanese mobo makers. Plenty of overclocking and tweaking options are available, too, including more extensive fan speed control than is offered in the BIOS.

Asus has been refining its Windows tweaking and overclocking software for years, and it shows with the latest AI Suite. Overclocking, memory timings, fan speed control, and the ability to save and load profiles: it’s all there.

For anal types (that’d be me) who like to keep tabs on all sorts of system variables, Asus also throws in its PC Probe II hardware monitoring app. PC Probe gives users plenty of variables to track and even a measure of interface customization, making this app one of the best in its class.

Specifics on specifications
The Asus and Intel boards we’re looking at today consolidate a cornucopia of sockets, slots, ports, and chips, all of which we’ve summed up in a handy specifications chart below.

There isn’t much here we haven’t already covered. However, it’s worth mentioning that the Asus and Intel boards differ on the Firewire and Ethernet fronts. If you’re after 1394a connectivity, the Rampage Formula provides it through a VIA Firewire chip, while the Bonetrail opts for silicon from Texas Instruments.

Gigabit Ethernet provides a little more intrigue, with the Asus board sporting a pair of Marvell 88E8056s against a single Intel 82566DC. So the Rampage doubles up on the Bonetrail’s GigE connectivity, but that’s not the interesting bit. Back when Intel launched its ICH9R south bridge, the chip’s block diagram showed an integrated Gigabit Ethernet controller—one motherboard makers would apparently be able to tap through a simple PHY (physical interface) chip. The design apparently didn’t catch on with mobo makers, and we hadn’t seen any boards take advantage of the ICH9R’s integrated networking capabilities. However, the 82566DC on the Bonetrail boards is a PHY chip that hooks into the ICH9R south bridge, providing our first glimpse of Intel’s integrated GigE solution.

Our testing methods
Obviously, we’ll be pitting the Rampage Formula and DX48BT2 against each other. We’ve thrown in a collection of LGA775 motherboards based on a variety of different chipsets to liven things up a little, as well. Those results should provide a good frame of reference for the kind of performance that can be expected from most of the enthusiast-oriented Core 2 motherboards currently on the market.

All tests were run three times, and their results were averaged.

Thanks to Corsair for providing us with memory for our testing.

All of our test systems were powered by OCZ GameXStream 700W power supply units. Thanks to OCZ for providing these units for our use in testing.

Finally, we’d like to thank Western Digital for sending Raptor WD1500ADFD hard drives for our test rigs.

We used the following versions of our test applications:

• SiSoft Sandra Standard 2008 13.12
• WorldBench 6.0 Beta 2
• TCD Labs HD Tach 3.01
• Call of Duty 4 1.4
• RightMark Audio Analyzer 6.06
• NTttcp
• Crysis 1.1
• Enemy Territory: Quake Wars 1.4
• Half-Life 2: Episode 2
• CPU-Z 1.41

The test systems’ Windows desktop was set at 1280×1024 in 32-bit color at an 85Hz screen refresh rate. Vertical refresh sync (vsync) was disabled for all tests.

All the tests and methods we employed are publicly available and reproducible. If you have questions about our methods, hit our forums to talk with us about them.

Overclocking
For our overclocking tests, we dropped the CPU multiplier to 6X—its lowest possible value. We also reduced the memory bus speed to keep our DIMMs operating within their limits. Next, we turned our attention to the front-side bus on each board, cranking it up and using a two-way Prime95 load to test stability along the way.

The DX48BT2 was up first, and overclocking it was a bit of a chore. We eventually got the board stable with a 460MHz front-side bus, but no amount of extra voltage or dark magic would coax 470MHz into stability under load.

460MHz is nothing to sneeze at, but it’s hardly spectacular by Core 2 motherboard standards. We’ve had plenty of cheaper P35-based motherboards reach that speed and higher. The real problem with overclocking the Bonetrail board is the fact that you have to reset a motherboard jumper after a failed overclocking attempt. Most high-end motherboards are capable of recovering gracefully from a failed attempt by rebooting with BIOS defaults, which is considerably more convenient.

By comparison, overclocking the Rampage Formula was a snap. The board automatically reboots with BIOS defaults if you push it too far, and even if you go beyond the point of auto-recovery, there’s still a CMOS reset button in the port cluster.

Not that we needed it. The Rampage sailed up to a 500MHz front-side bus without so much as a voltage tweak. We had to increase the front-side bus and north bridge voltages by 0.1V each to get the board stable at 510MHz under load, and that was all she wrote. 520MHz refused to post, even with additional voltages applied all around. Not even the board’s auxiliary cooling fan made a difference.

Of course, as is always the case with overclocking, your mileage may vary.

Power consumption
We measured system power consumption, sans monitor and speakers, at the wall outlet using a Watts Up Pro power meter. Power consumption was measured at idle and under a load consisting of a multi-threaded Cinebench 10 render running in parallel with the “rthdribl” high dynamic range lighting demo.

The Rampage and BT2 have virtually the same power draw under load, but the Asus board is more frugal at idle. It’s curious, though, that the idle power draw of Asus and Gigabyte’s X48 boards is lower than that of Intel’s own.

Memory performance
Memory subsystem performance doesn’t always track with real-world applications, but it’s a good place to start our performance benchmarks

Things don’t look so hot for either board here, with the Rampage and DX48BT2 filling out the back of the pack in our memory bandwidth and latency tests.

Memory controllers don’t always handle four DIMMs gracefully, so we popped an additional two memory modules into each system for another round of tests. In these tests, we had to back off to a 2T command rate for the nForce 780i SLI, Rampage Formula, and DX48BT2—a common adjustment for four-DIMM configurations.

Moving to four DIMMs only makes matters worse for the Rampage and BT2. The Rampage’s access latencies are quicker this time around, but neither board manages to match the performance of Gigabyte’s X48-based X48T-DQ6, let alone the others.

WorldBench
WorldBench uses scripting to step through a series of tasks in common Windows applications. It then produces an overall score.

Now here’s an interesting result: the bottom three rungs in our WorldBench results are occupied by boards based on Intel’s flagship X48 Express chipset. So much for a high-end performance advantage.

To be fair, only four points separate the fastest boards from the slowest here. The results are somewhat tainted by inconsistency in WorldBench’s WinZip test, which seems to be affected by Vista’s supposedly intelligent caching scheme. The Rampage Formula and X48T-DQ6 both turn in completion times in the WinZip test close to a minute slower than their competition for no apparent reason.

Gaming

Even at these relatively modest resolutions, games tend to be bound more by the graphics card than by a system’s motherboard. The biggest gap in performance comes with Quake Wars, and even then, you’d be hard pressed to tell the difference between 119 and 130 frames per second.

Motherboard peripheral performance
To provide a closer look at the peripheral performance you can expect from these motherboards, we’ve complied Ethernet, USB, Firewire, Serial ATA, and audio performance results below. You’ll notice that there isn’t much variance from one board to another, but there are a few things worth pointing out. The Rampage Formula and DX48BT2 are highlighted and in bold to make them easier to pick out from the crowd.

The Rampage Formula and DX48BT2 both do well in our Ethernet performance test, with the Intel board registering the lowest CPU utilization of the lot.

Repeat after me, Asus: I will not use slow VIA Firewire chips on $300 motherboards.

Nothing to see here. Move along.

Yeah. Uh-huh.

So much for audio risers. The Rampage Formula’s SupremeFX card does little for the board’s score in our RightMark Audio Analyzer signal quality tests. The Rampage doesn’t score any better than the BT2 with its Sigmatel codec.

Conclusions
The DX48BT2 motherboard proves Intel is indeed capable of building a decent enthusiast-oriented motherboard complete with overclocking and tweaking options. The Bonetrail board even has a leg up on the Rampage Formula in the features department, offering a third PCI Express x16 slot and external Serial ATA connectivity. Unfortunately, that’s not enough to make up for the board’s shortfalls, which include SATA port layout problems and BIOS quirks that make overclocking more frustrating that it needs to be. It doesn’t help that the board is no faster than much cheaper alternatives or that it’s bound to extremely expensive DDR3 memory.

The BT2 isn’t a bad board by any stretch, and at $244 online, it’s one of the most affordable X48-based motherboards on the market. But it’s just not up to the standard set by Asus’ Rampage Formula. The Asus board has better BIOS functionality, a superior layout, additional features like an external CMOS reset button and POST code display, and apparently greater overclocking headroom. Throw in a copy of S.T.A.L.K.E.R. and all the money you’ll save by being able to use DDR2 memory, and we’d be more inclined to pay the higher $292 asking price for the Rampage.

Not that Asus has the perfect, er, formula for the X48 Express. The Rampage’s lack of eSATA connectivity and its slow Firewire chip are a little embarrassing for such a high-end offering. Asus would have done well to take advantage of the X48 Express’ support for more than two-way CrossFire configurations, as well. But the real problem that besets the Rampage Formula, and indeed all other X48 motherboards, is the fact that they offer little or no performance advantage over much cheaper alternatives based on the P35 Express chipset.

Then again, high-end motherboards are probably more about bragging rights and convenience than sheer value. By those standards, the Rampage Formula is certainly a better option than the DX48BT2.