Intel is changing the future of power supplies with its ATX12VO spec

Post by jhasse » Tue, Mar 10, 2020, 8:24 AM UTC

chrisseaton wrote: post #60

DiabloD3 wrote: post #27

Four important things to consider: First, this already happened to some extent. Outside of drives and fans, the virtually all of the power used in your system is exclusively 12v; either from the 12v pins on your ATX24 or P4 or EPS12 connectors, or via the PCI-E connectors; very little non-drive or non-fan power is supplied via 3.3 or 5v rails. Second, almost all PSUs today use 12v DC to 3.3/5v DC converters to increa…

> Fourth, Intel is also not the dominant player in the field now, AMD is. This is delusional - AMD’s market share is like 15%.

Post by guerrilla » Tue, Mar 10, 2020, 8:39 AM UTC

numpad0 wrote: post #98

vifya wrote: post #53

It was bound to happen eventually, there has been a long trend towards point-of-use regulation displacing multiple output supplies. I'm just surprised they went with 12V, and not 19V which has lower rectification losses, less power loss to wire/trace resistance, and a large existing design ecosystem from laptops where 19V has been the norm for years.

Why is it 19V for laptops? I had suspected it’s to compensate for voltage drop at linear regulators. Batteries are either 11.1(3.7v 4 cells) or 14.8(3.7v 3 cells 1-3 parallel) and these voltages doesn’t seem immediately consistent with ATX12V to me.

Post by dezgeg » Tue, Mar 10, 2020, 8:58 AM UTC

garaetjjte wrote: post #14

baybal2 wrote: post #10

Earlier quoted context omitted.

Indeed, found that for myself when got into mobo design. ATX 5V is really unsuitable for USB power, and can play tricks on you. Similarly, 3.3V from PSU is useless at powering 3.3V logic. You have to do power staging on board to guarantee that PCI and i2c stuff turns on after the bridge/soc. Some PSUs don't follow reset timings, or don't do them at all on standby rail. So if you do ATX power by the book, you may end…

>ATX 5V is really unsuitable for USB power, and can play tricks on you. Why? I don't think current motherboard duplicate 5V converter. >you may end up with improperly inited board, and 3.3V ICs booting up before the CPU. Why it cannot just hold reset line for these chips high until CPU started?

Post by baybal2 » Tue, Mar 10, 2020, 9:17 AM UTC

chmod775 wrote: post #26

baybal2 wrote: post #13

Earlier quoted context omitted.

±5% would not be that easy with current spikes from CPU and GPU. It's 300W-400W load going to near zero and back within microseconds.

It's not black magic to handle that with a capacitor or two.

Post by thehobgoblin » Tue, Mar 10, 2020, 9:27 AM UTC

numpad0 wrote: post #98

vifya wrote: post #53

It was bound to happen eventually, there has been a long trend towards point-of-use regulation displacing multiple output supplies. I'm just surprised they went with 12V, and not 19V which has lower rectification losses, less power loss to wire/trace resistance, and a large existing design ecosystem from laptops where 19V has been the norm for years.

Why is it 19V for laptops? I had suspected it’s to compensate for voltage drop at linear regulators. Batteries are either 11.1(3.7v 4 cells) or 14.8(3.7v 3 cells 1-3 parallel) and these voltages doesn’t seem immediately consistent with ATX12V to me.