Why don't we have 12V CPUs?
Why don't we have 12V CPUs?
Hi, over the last couple of days I've been thinking about why we don't commonly use higher voltage CPUs anymore. I searched online but mostly found discussions about 12V power rails, extension cables, and related accessories. That's why I got a bit bored scrolling. My curiosity really started after watching a video about the new 12V PSU standard. From there, I began imagining what it would be like to use 12V CPUs. I remember that older CPUs from the 90s to early 2000s often ran on 5V with lower current requirements. But I'm still puzzled by the reason behind this shift. I don’t have an electrician who could clarify things, and after scrolling through over a thousand unrelated topics online, I felt overwhelmed. My questions: Why choose 12V? Could it be more efficient in power delivery? Maybe PSUs and MOBOs wouldn’t need as many VRMs for lower voltage conversion. Less current might mean less heat, which could extend the CPU’s lifespan. Would that make sense? Do CPUs and other parts actually require a certain amount of current to function properly? I’m not sure if I’ve missed something important. My understanding comes mainly from basic school lessons, so I might be missing the key point that explains “why not.” I really appreciate any help with this.
It might destroy the CPU right away because the voltage isn't stable enough for the chip to operate safely. The board should provide consistent power, but if the voltage fluctuates too much, the silicon can't function properly.
The processor has a limited maximum resistance, meaning it can only handle so much current at a specific voltage. To provide more power, raise the voltage slightly—this allows it to draw more current. If you boost the voltage by about ten times (modern CPUs typically operate between 0.9 and 1.2 volts), you'd supply ten times the current, creating excessive heat and waste. Reducing resistance helps control the current, but much of the energy ends up as heat. Power delivery at 12 volts is already efficient, so losses between the power supply, VRMs, and CPU aren't significant. For instance, a new 12VO PSU removes lower voltage outputs and delivers just 12 volts directly to the motherboard, handling regulation internally.
P equals I squared times R. For a material with consistent resistance, reducing current means less power P equals voltage times current. Greater voltage demands lower current for identical power output. This explains why electric towers use kilovolts and transformers adjust voltage before delivery. In chip design this concept matters less; however, for silicon transistors the gate voltage is about 0.7 volts, which sets a physical boundary. Unless your system uses 12 volts DC, you’d need conversion. Also, wall power often fluctuates, so regulators are essential for stable operation. Essentially, using 12 volts directly on a CPU would need a different material, unless your voltage supply is stable. Mm, it really depends on the materials involved.
Yeah, I know what you're saying, but I'm not sure I got it right. If I did understand it, there doesn't seem to be any reason, but I might have misinterpreted it.