Hacker News Reader

Hacker News

Comment by mmastrac | Hacker News Reader

Parent Full thread

mmastrac

Probably would allow very cheap power supplies w/built-in UPSes. 12V±5% voltage is the allowed range.

View on HN

±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.

It is, first the cap needs to ve huve enough, second ESR will need to be very, very low unless you want to cool the cap as well

Most desktop users would probably prefer a UPS that also ensured their monitor stayed on.

I actually leave my monitor off UPS intentionally. While I'm away, I'd rather my workstation survive a brownout or short loss of power and if I'm actively working, it's easy enough to move the monitor's power cable to the UPS to save my work and shut down. My CPU draws ~45W at idle; my monitor draws a whopping 130W — having it on battery materially shortens the off-AC runtime.

Your monitor shouldn't draw 130W at idle. My 34" monitor is ~3W in sleep mode, 34W when on. Even my eight year old 55" TV only draws 90W when on.

It's a 10 year old TFT: https://support.hp.com/us-en/document/c02159509

"Typical power consumption: 130 W."

Right, but doesn’t it suspend when you’re away? DPMS should be at least an order of magnitude less, if not two.

Nope. I turn it off when I'll be away for a long time. But not if I'm just grabbing food or doing some housework or whatever.

Older high-end monitors with CCFL backlights could easily draw 130W. Dell's 30-inch model from 2008 was rated for typical draw of 163W and a max of 250W (when also powering speakers and USB devices).

Indeed, this is a HP 30" from 2010.

If your goal is to game or work during a power outage, sure.

If your goal is just to protect your data from sudden termination, then having a PSU with a built in UPS is quite nice.

Being able to power any external device (like a hard drive) or to be able to cleanly exit from whatever you're working on if you happen to be present (with a monitor) are both pursuant to these goals.

The average PC or workstation isn't configured for a clean exit just because the UPS said it's time.

Bridging momentary outages is also useful where that's common, disregarding data loss.

They ought to be able to exit cleanly in time... that's what hibernation is for.

What they are saying is that in the case with their setup they can't trigger shutdown or hibernation without a backed up KVM.

why not put the 12v power supply inside the monitor?

Reply on news.ycombinator.com