A device that most people under thirty have never heard of is located somewhere between a VAX terminal and a first-generation iPhone on a shelf in a museum of computing history. The M700 Glofiish. E-TEN, a Taiwanese business, produced this 2006 Windows Mobile PDA phone. It included a stylus and a 400 MHz Samsung processor. It appears to be completely out of date. Additionally, if you know what you’re looking at, this piece of gear is remarkably informative.
That device’s Samsung SC32442 processor was attempting to fit everything onto a single piece of silicon, which sounds similar to anyone who studies contemporary chip design. The application processor, memory controller, and some baseband functionality are all crammed onto a single die, controlled by crude power circuitry, and only the plastic case and surrounding air provide cooling. Anyone who used the device for more than a few minutes of serious work could see the limitations this posed right away. The chip warmed up. Performance declined. With various numbers, the engineers had reached the same obstacle that chip designers continue to face today.
The most straight route from 2006 to the present is the tale of electricity management. In order to reduce heat and prolong battery life, the SC32442 employed a simple type of dynamic voltage scaling, which involves lowering the power applied to the processor when full performance isn’t required. By today’s standards, it was rudimentary: it applied to the entire chip rather than just certain parts of it and effectively had two or three operational states instead of continuous adjustment. Engineers refer to the individual clusters of cores that make up modern SoCs from Apple, Qualcomm, and Samsung as “power islands.” These clusters have their own voltage regulators and can be turned on, ramped up, throttled, or completely turned off in milliseconds, independent of what the rest of the chip is doing. The idea is the same. The granularity is finer by orders of magnitude.
The historical comparison becomes nearly unpleasant in its continuity at thermal throttling. Because the heat produced by a 2006 Glofiish had nowhere to go—no fan, no heat pipe, just a thin slab of metal and plastic—it was unable to maintain top clock speed indefinitely. The same limitation applies to modern high-end smartphones. The new iPhone’s Apple A18 Pro can achieve outstanding peak performance numbers in brief bursts, but if you push it hard for a lengthy period of time, such as during a prolonged gaming session or video encoding, thermal throttling takes over. The speed of the clock decreases. The long-term performance falls short of the peak. Over the past 20 years, engineers have significantly raised this ceiling. They haven’t gotten rid of it.
When viewed from a distance, the Glofiish architecture shows that the industry spent the next 20 years developing more complex solutions to the same underlying physics after identifying and partially resolving the fundamental tensions in mobile chip design in the mid-2000s. A pocket-sized device cannot have limitless performance without heat acting as a constraint. It is not possible to run every component constantly at full power without depleting the battery more quickly than customers feel acceptable. The limitations are mostly related to the non-negotiable characteristics of silicon, electricity, and thermodynamics rather than intelligence or inventiveness.
Anyone who is genuinely interested in the history of technology will find a particular type of intellectual joy in watching researchers trace design lineages through processor generations. In engineering terms, the difference between an ARM920T core operating at 400 MHz and Apple’s bespoke ARM cores operating at multiples of that speed while using less power is huge. However, there is a continuous rather than a discontinuous path between them. Every generation of chips inherited the issues that the preceding generation was unable to completely resolve and devised more effective solutions to cope with them. The Glofiish is located close to the start of that contemporary mobile arc, not as a relic to be disregarded but rather as a point of reference for comprehending the appearance of modern chips.
