RAM | Reseller Advocate Magazine: Issue 55

By Chris Angelini

nobody likes a complainer, but put your critical hat on for just a moment. What is it about your PC that you'd change if given the chance? We're not talking about significant others here, so don't be afraid of hurting anyone's feelings. Be honest. Are you bothered by the sound of four case fans, desperately trying to suck air away from hardware that tends to crater in the face of intense heat? And let's face it, for every ounce of performance folded into your white box batter, your customer pays a hefty premium either in large copper heatsinks, aftermarket water cooling kits, or (even worse) failure from an improperly ventilated component. Ouch. Unfortunately, more airflow and heavier heatsinks seem to represent the necessary evolution of today's ATX form factor—not particularly elegant.

Solving Problems, Taking Names

Think back a couple of years, before there was any buzz on the Core architecture. Intel's NetBurst was still king and the Pentium 4 looked like it would scale massively. I distinctly remember murmurs of speeds upwards of 10 GHz, with 5 GHz almost imminent. Given the chip's heat dissipation at the 3 GHz level, it was clear that a scaled-up variant would present interesting thermal issues.

And so Intel set out to work on BTX, successor to the aging ATX form factor with which most resellers are familiar. According to the company, ATX faced six challenges that BTX could effectively address. These challenges impact all system builders using ATX, affecting their ability to compete against tier-ones with proprietary ducting designs. In case you haven't noticed, most of those boxes are impressively quiet yet still support high-end hardware.

The first big issue to address was actually a combination of two related hurdles: increasingly expensive cooling and noise that was ramping up correspondingly. Examples abound in the world of ATX. Certain enthusiast customers will always want the baddest cooling mechanisms, if only for show. But compare the big blocks of copper shipping as reference designs with boxed Pentium 4 and Athlon 64 processors to older heatsinks. They're heavier, more voluminous, and made of more expensive materials. Add an active heatsink to your motherboard northbridge, then toss two extra case fans into a chassis. Slowly but surely, the BOM on your white boxes starts creeping higher. The extra noise is a slap in the face, too.

Keeping it Cool
The BTX form factor goes a long way in making the most of cooling. As you can see, the processor, MCH, and ICH are all aligned on this Intel D945GBO board, eliminating the need for active cooling on most motherboard components.

BTX simplifies cooling by involving only two fans, even in the most powerful configurations. One is the thermal module, to be explained shortly, and the other is a power supply fan already found in most PSUs. Motherboard components on a BTX platform are rearranged so that they fit within a single high-velocity air passage, all cooled by the thermal module. Consequently, BTX helps you achieve more efficient cooling without conventional noise levels.

Scalability is another of BTX's advantages, less sensationalized than the first two. When ATX was first conceptualized, the whole small form factor craze hadn't yet taken place. Layout was far simpler, too. Today, unfortunately, resellers looking to take the small form factor route often pay for proprietary barebones kits. And as we've seen, those vendors are quite inclined to turn around and offer their built-to-order product directly to your customers. BTX enables a much more flexible standard interface to which everyone has access. There are two different thermal module designs and four board layouts, each sharing that core high-velocity air passage. Plus, two fresh power supply specs—LFX12V and CFX12V—fit within the constrained dimensions of a SFF box.

Along the same lines, BTX takes a burden off of motherboard manufacturers who face the increasingly difficult task of situating a lot of integrated technology. According to Intel, a few specific areas are particularly tricky: processor power delivery, the ICH (southbridge) to I/O routing pathways, and MCH (northbridge) to memory routes. By specifically creating more room for each of those problematic zones, the motherboard vendors save money on R&D.

The last two concerns on Intel's checklist of ATX shortcomings are closely related to the first two. Mainly, the ATX platform isn't built to support the massive heatsinks we're seeing sold nowadays, and the shifting thermal landscape is starting to cost everyone, from vendors to end users, more money. Once again, BTX is being positioned as the answer. First off, it delivers a 100% increase in allowable heatsink mass (up to 900g) thanks to a universal retention module that bolts directly to the chassis. In turn, standardization makes it more affordable to replace ultra-customized cooling subsystems with cheaper, more compact components.

The Ingredients List

As a system builder, transitioning from ATX to BTX is a lot like learning to prepare Beef Wellington after a career of pounding cube steak. Sure, you're still working with meat, but it's a much more savory dish. The new recipe requires a different list of ingredients, naturally, and it might not come out right on your first attempt. However, with a little research, trial, and error, you should have little trouble discovering the immense benefits of BTX, learning how to spec out a BTX machine, and turning the standard's advantages into compelling differentiators.

First, the list of ingredients. According to Peter Brandenburger, BTX program manager in the platform application engineering group at Intel, BTX is best approached from the chassis level. ATX is a thing of the past once you cross over, since a BTX chassis boasts several features you won't find back in the ATX camp. For example, a BTX case sports the screw holes needed to secure a Support and Retention Module. Most also employ thermal module interfaces—built-in ducting mechanisms of sorts designed to channel air most effectively. And because the I/O on a BTX motherboard is completely different, the right chassis is needed for a flush fit.

Not Your
Father's Heatsink
This Type I thermal module incorporates a heatsink, fan, and retention mechanism, all of which bolt directly to a chassis. In turn, it holds up much better during shipping, focuses air more efficiently, and supports up to 900g of mass.

Your case of choice will almost always dictate the motherboard contained within. BTX boards are organized into four size classes: picoBTX, with room for one add-in card, nanoBTX, accommodating two, microBTX, with enough space for four slots, and full-sized BTX, topping out at seven. The core of each board layout is the same, exploiting the single air channel concept, while just the pathway to expansion differs. As a result, boards are easier for resellers to support since much more of the infrastructure remains consistent.

The different sizes align themselves with specific applications, as you might expect. Just as you'd generally use a full-sized ATX motherboard in an enthusiast box, BTX works the same way. And with picoBTX and nanoBTX coming online this year, the small form factor market will suddenly become much more profitable for VARs who have thus far seen limited margin. Chassis size also helps dictate the thermal module you'll use. In an ATX build, a heatsink sits on the processor, usually attaching to a retention mechanism on the motherboard with clips. BTX instead leverages a Type I or Type II thermal module, a combined heatsink, fan, and duct that screws directly into the chassis, putting way less stress on the PCB and allowing more customization of platform size. A Type I module is larger, designed to support everything between full tower to small form factor configurations. Type II modules are low-profile, optimized to work with ultra-thin boxes.

"A low-profile Type II thermal module helps enable BTX platforms measuring 3" on the Z-plane," says Intel's Peter Brandenburger. "Existing ATX small form factor designs just can't get that small."

The final two BTX-specific components of note are the Support and Retention Module, which should be included with any BTX chassis you purchase, and a compatible power supply, also widely expected. Interestingly enough, full-sized BTX boxes employ existing ATX12V power supplies. Mini-towers, presumably equipped with microBTX boards, may feature SFX12V supplies. The CFX12V and LFX12V standards, currently slated for broader availability this year, help support the smallest form factors.

Interpreting the Delays

BTX Goes Mainstream
The ecosystem of BTX hardware is still developing, so product options are sparse. Antec recently threw its hat into the market with a full-sized, sub-$90 BTX case that sports universal appeal.

When starting this piece, I was under the impression that tier-one OEMs were moving slowly to adopt BTX, instead leveraging their own proprietary designs and leaving a tremendous opportunity open for the channel to swoop in and sell a better product. However, a quick Google search reveals that Dell, Gateway, and HP have already recognized the advantages of BTX and are enjoying the benefits.

"The channel," points out Intel's Brandenburger, "is lagging on this one."

So why the disinterest in BTX given all of its real world utility? The big tier-ones are onboard, after all. At least right now, the problem seems to be one of price pressure. Because BTX is a somewhat new idea, the corresponding components still command a noticeable premium. It doesn't help that the slow adoption of BTX has resulted in low volume sales.

There is even a number of hardware vendors who have taken a wait-and-see approach to the form factor, hoping to watch it gain popularity before plunging headfirst. Third-party motherboard manufacturers represent probably the clearest example; few are shipping retail BTX product at all. Fortunately, Intel is feeding ample BTX, hardware to the channel. "At first we hesitated on BTX as well," says Scott Richards, worldwide vice president of sales and marketing at Antec. "But BTX is clearly the most elegant form factor solution out there, and we're committed to giving resellers the option to go that route with our BK640B case."

Indeed, Antec's timely BTX chassis launch was the catalyst that got me going on BTX. Despite its enthusiast aesthetic and the powerful dual-core processor I installed, noise under full load remained minimal. Hours after building my first BTX example, I was already hooked.

A Bright, Shiny Future

The current crop of BTX components, first introduced to the channel in 2005, is decidedly centered on the Type I thermal module. Motherboards, cases, and boxed processors all back the larger layouts. When you factor in the initial premium tied to those BTX designs, it's little wonder that resellers have been slow to make the transition.

High Speed, Low Drag
As the hardware infrastructure supporting smaller BTX builds and Type II thermal modules develops, you’ll have more opportunities to build tiny home entertainment and office desktops.

But Intel remains confident in its efforts. According to representatives, though the first batch of BTX parts encountered resistance, the hardware infrastructure supporting Type II thermal modules will empower resellers with even more compelling product. Launched in the first quarter of this year, VARs will slowly see the requisite ultra-slim components come online. The arrival of boxed processors with Type II modules is imminent. Intel already sells a picoBTX motherboard. And chassis manufacturer Chenbro is reportedly tooling up a small form factor BTX chassis to complement its existing microBTX offering.

"The greatest thing about the upcoming wave of tiny BTX systems with Type II modules is that they translate so well to our Viiv initiative, giving resellers a real opportunity to absorb some of the premium currently tied to BTX," says Dan Snyder, an Intel spokesman.

Even though BTX was first conceptualized as a means to cope with the rising heat of Intel's NetBurst architecture—soon a thing of history—there will always be room for better thermal management, lower noise levels, and smaller form factors. Intel is still very much behind the initiative, motherboard and chassis partners are slowly vocalizing support, and the hardware needed to build BTX machines with Type II modules should see availability soon. Viiv gives resellers a perfect application for those diminutive boxes, while vPro will do the same later this year. I know that BTX components cost a bit more than ATX and availability is still pretty tight, but if you've never experienced the platform's advantages, by all means, put one system together and listen to the difference.