100 PCWorld APRIL 2020FEATURE INTEL IS CHANGING FUTURE OF POWER SUPPLIES
the thick 24-pin Main Power Connector
would drastically drop down to a tiny 10-pin
connector, similar to what we saw with Intel’s
Compute Element (go.pcworld.com/cmel)
earlier this year.IT’S ABOUT THE EFFICIENCY
This efficiency gain is the main reason for the
push toward ATX12VO. “As desktop
computers continue to become more energy
efficient, the power supply AC-to-DC
conversion loss can be the biggest consumer
of power in a computer at idle,” Intel officials
told PCWorld. “Existing ATX multi-rail power
supplies (5V, 3.3V, 12V, -12V, 5VSB) are not
very efficient at low loads of today’s desktop
computers when at idle,” according to Intel.
Because the multi-rail power supply issending very low current to all
voltage rails, efficiency is just 50
percent to 60 percent.
The new ATX12VO spec
significantly improves that
efficiency. “By converting to a
single rail power supply,” Intel
explains, “the conversion losses
can be minimized, reaching up to
75 percent efficiency at the same
DC Load levels.”
While increased efficiency
means less power used and less
money going to the power
company, PC vendors aren’t
making the move of their own
volition. They’re doing it to comply with
ever-tighter government regulations on power
consumption by personal computers—
specifically, California Energy Commission’s
Title 20, Tier 2 requirement, which goes into
effect in July, 2021. “The most recent
government energy regulations are requiring
OEMs to extreme low system idle power levels
to reduce desktop idle power consumption,”
Intel explained.
Although you might expect California’s
CEC to focus mostly on how much power a
desktop or workstation burns under load,
regulators are actually focusing on increasing
idle and standby efficiency, which they
believe yields the most benefit for power
savings. The assumption is that desktops are
idle far more than they are under load.Vendors say it’s difficult to reach increasingly stringent idle
standby power requirements with power supplies that produce
3.3-volt and 5-volt power, so the new ATX12VO spec will move
that support to motherboards.