

As cases get smaller and CPUs get faster, system builders have to wrestle with four opposing design constraints–performance, power consumption, audible noise output, and thermal management. There are no magic-wand fixes to this challenge, but you can make better trade-offs to achieve optimal performance without creating a small typhoon inside the PC case.

Intel’s Floyd Goodrich gave a talk at IDF Fall 2004 about new initiatives underway at Intel to help system designers make some of those better choices. His talk focused on acoustics, but the other issues–power draw and heat–cannot be ignored in pursuit of a quieter high-performance PC. The three are inextricably linked.

Intel took the wraps off Thermal Management 2 and Enhanced Intel SpeedStep Technology, both intended to improve Pentium 4 performance while reducing power draw and heat. These goals in turn aim to quell the final adverse side effect–fan noise.

Some Like it Hot

Thermal Management 2 improves upon the original Thermal Management technology Intel introduced in its Pentium 4 CPUs. Recall that if a thermal sensor reports that the CPU temperature is above a specified limit, an alert is sent to the BIOS (an event called “PROCHOT” or processor hot). As a result, the CPU’s clock speed is cut in half to prevent the CPU from arc welding itself into the motherboard. Intel has taken that existing design, and made improvements to the PROCHOT state, wherein the CPU’s operating clock speed is now a faster fraction of the normal CPU operating clock speed.


Whoa, Big Fella

Goodrich also covered Intel’s new Enhanced SpeedStep Technology (EST), which will first appear in newer Pentium 4 CPUs later this year, although he didn’t state which specific CPU model. Grafted from the company’s mobile CPUs, the original SpeedStep technology basically had two settings–plugged in, and battery mode. EST takes this technology to the next logical step by opportunistically having the CPU go to a lower power state during non-peak execution. The feature will be controlled by the operating system, and the net effect of “throttling” the CPU is that the average power dissipation and resultant thermal load can be reduced.

Goodrich also spoke briefly about how the new Balanced Technology Extended (BTX) format will help designers in their quest to create high-performance systems in ever-shrinking form factors and pointed them to a web site called, where copies of the specs for the different formats are available.

One such new case size, the Entertainment PC, poses an ongoing challenge, since many of them are laid out in smaller cases designed to fit into A/V component racks. In addition, the entertainment center racks themselves may not have especially good air-flow, but there’s still the expectation that a PC in this environment won’t generate much fan noise. The combination of Thermal Management 2, Enhanced SpeedStep Technology, and the new BTX form factor will hopefully bring to market high-performance systems that can live in a component rack or other noise-sensitive environments, while keeping the whoosh-factor to a minimum.