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How much power the system is REALLY consuming?

I suspect that my ATX case's power unit from China provides FAR LESS power than it's supposed to. Is there a way to see (in real time) how much power the whole system is trying to consume and how much is it really getting? Maybe, not in watts, but the voltage is not enough, say, 4.5V instead of 5V. What I really need to know, is should I return the power supply to a shop and buy another one.

Just in case (I don't know, do the following components support power consuming feedback):

  • PCI-E 2.0 PALIT GTX550Ti, NE5X55T0HD09-1061F, 1Гб, GDDR5
  • ECS H67H2-M3 LGA 1155, mATX
  • INTEL Core i5 2300, LGA 1155

NO FORMULAS, PLEASE. I can calculate the summary power on my own. I need REAL TIME consuming data.

NO KILL-A-WATT LIKE DEVICES, PLEASE. I need power consuming data AFTER the power supply, not of the (system + power supply itself).


This is my HW Monitor Screenshot:

enter image description here


What I've learned from the answers. This problem is not solvable by people like me. I'm not kinda electrician man, and I have no multimeters/testers. It's too much for me to buy one just for this private task. (Though, I have to, maybe, to be able to solve such tasks in future). Without hardware, I can control voltage only, that can prove the suspicion but not refute. To make the things worse, software like HW Monitor is buggy, since it shows VIN1 values instead of +3.3V like in my case.

P.S. Since I've replaced DDR3 memory, no more BSODs, so I think, the power supply is OK.

Source: (StackOverflow)

Can I safely charge my laptop with a non-standard, third-party charger?

I have a Toshiba Satellite laptop. My charger has stopped working.

I have access to a Lenovo charger. Can I use this charger on my laptop?

Source: (StackOverflow)

Power consumption: SSD vs HDD

In questions like this one and in websites everywhere it's noted that SSDs use much less power than HDDs... usually citing ~2 W vs ~6 W for HDDs, my question (and sorry if its stupid just need to be exact) is that per hour? Need to calculate costs savings in power consumption if we switched all our workstations to SSDs

Source: (StackOverflow)

Buying A Computer "Case" Fan... Does It Always Run At 100% Unless Told Otherwise?

What happens if I do not plug it into the motherboard and it does not have a switch?

I have seen fans before with an "off/low/high" switch that allows you to manually set their speed.

I have seen fans that plug into the motherboard and are controlled by the OS.

I am curious... what does a fan do by default when plugged into a PSU? Does it run at 100% unless otherwise told to go slower? This is what I would expect...

Source: (StackOverflow)

Do SSDs “turn on”?

Hard-drives have a definitive “on” status (they spin up, the heads move, and they use more electricity than when they are “off”). The same goes for a computer (fans and lights activate), monitors (relays click, electron-guns fire/LEDs light), and so on. But what about SSDs?

A hard-drive requires the disk to be spinning and the head to have power in order to read or write, but an SSD is more like RAM when it comes to reading and writing; it requires no movement, just a direct electrical write. Further, unlike RAM which needs to be continually refreshed to retains its contents, SSDs retain it after one write like hard-drives (SSDs are the best of both RAM and HD).

Therefore, do SSDs have a definitive on and off state or are they just a lump of electronics that sits there doing nothing until an actual read or write operation, and only use electricity then?

(Power-management may complicate things a bit since most devices are “turned off” while they still retain a trickle charge. Therefore, most devices are either “on”, “off”, or in “standby”. This doesn’t change the question though, since I’m asking about normal “on” usage, not standby.)


Thanks for the responses (I’m familiar with how electronics work; I recall all too clearly some of my uni exams), but all the current answers miss the crucial point to the question: a device (eg HD, monitor, etc.) that is “on” uses significantly more power than when it is off (or even standby).

Does this apply to SSDs as well?

Note: I had the thought that SSDs (including regular flash drives and memory cards) do seem to be “always on” in that they are immediately accessible. That is, unlike a hard-drive or optical drive which can spin down or at least take a moment to access when they reduce power, files stored on a flash drive are always instantly accessible no matter how much time has passed without it being accessed. (I suppose that could lead to the question do SSDs turn off (eg to conserve power) instead, but that would be a separate question, if even required—which it is not).

Source: (StackOverflow)

Why does pulling the power cord then pressing the power button fix a non-booting PC?

I've been working at this institution for about 6 years. One thing thing that I've always found curious is that sometimes—especially after a power outage—we find a PC that won't boot when the power button is pressed. Usually, the fans will spin up, but it won't POST. Our solution is to pull the power cord, press the power button with the computer unplugged, then plug it in and turn it on. It seems more common with Gateway brand PCs than the Dells or HPs that we have around.

Does anybody know what pressing the power button does when the computer is unplugged? I have some vague notion that closing the power button circuit allows some capacitors to discharge or something, but I'd like a firmer answer to offer my users when they ask me what I'm doing.

My best guess as to why fans can spin but it can't POST is that the BIOS is in some non-functional state. I don't know how BIOS stores state, but my best guess is that there is some residual garbage in its registers or something, like the stack pointer isn't starting at 0 maybe?

Source: (StackOverflow)

Does a power supply draw only as much power as it needs?

I recently built a small mini-itx Intel ATOM-based Ubuntu home server. The case I choose is a small case but only a full size ATX power supply would fit it. I choose a mid-grade OCZ 500 watt modular power supply for it and it works great. I could not find a modular ATX power supply out there that was less than 450W.

So my question is, does my 500W power supply draw 500W just because thats what it is? Or does the power supply only draw as much power as is needed to power the computer components?

One mini-itx ATOM board + two SATA HDDs = less than 100W I figure. My goal was to build a low cost, low power consumption server, so hopefully the 500W power supply isn't drawing 500W.

Source: (StackOverflow)

How much power does a hard drive use?

This is not as straight forward as it sounds.

Specs from Western Digital's site for a WD 3TB Green Drive:

  • Read/Write 6.00 Watts
  • Idle 5.50 Watts

Looks fine right? Look at this part of the spec: "12 VDC" and "Read/Write 1.78 A".

It was a long time ago, but when I was in college that would mean the drive uses 21.36 Watts (12V x 1.78A). 21.36 Watts is a lot more than the claimed 6.00 Watts.

I want to put four of these in a RAID 10 array, so I want to know the actual max power requirement.

Thoughts? Is this a simple typo? Do I need to plan on ~85 Watts of power to support four drives?

Source: (StackOverflow)

Is a UPS a good investment for a home machine?

Is it worth the money to invest in a battery-backed UPS unit for a home machine? Or is it a waste of money? The purpose of the UPS would be to prevent a "meltdown" of the computer due to bad power in the area, i.e. it's toast(tm).

With the cost of some computers, the UPS approaches half the replacement cost of the machine, which is why I'm asking.

Clarification: This answer is for the United States. Each country has their own power grid schema and have different levels of service. Here in the States, while power is plentiful and adequate, there are segments of the national grid that are getting old and are, at times, overburdened, leading to the occasional brownout. This is a rare occurrence but it is a concern.

Source: (StackOverflow)

How can I force an internal hard drive to power on or off when I want?

Obviously there are power management settings which Windows uses to determine when to power a hard drive off, and when to power it back on again. Powered down I assume doesn't mean absolute zero power, but it does mean the disk stops spinning.

I have a second hard drive which is a tad noisy. In fact, having invested in a new case, CPU cooler, power supply and fan-speed controller, it's now the noisiest component left in my computer. And I've kinda run out of money.

But... I don't need a second hard drive all the time.

So - is there a quick-and-easy way to make Windows unmount all partitions from a particular internal hard drive and power that drive down on demand, and then make it power the drive back up and re-mount the partitions when I'm going to need it?

Kinda the internal software-controlled equivalent of unplugging/reconnecting an external USB hard drive.

I dual boot, so I really need the answer for both Windows XP and Windows 7.

Source: (StackOverflow)

Detecting when a server is running on UPS battery

I have a home server (HP Proliant ML310 G4) that I bought from my employer a month or so ago. The server runs Debian Linux and I use it for just about everything. I can get away with doing this because my needs aren't that demanding so the server is rarely under heavy loads at any given time. This server has a 2 TB RAID1 array (with one hot spare) managed by mdadm that I use for file sharing over my network via Samba. I'm running the OS off a smaller hard drive that is not part of the array.

I have the server powered through a small 255-watt UPS because I need it to withstand minor power fluctuations without coming down. This is very important because a sudden unclean shutdown (caused by a power drop or blackout) can screw up the RAID array, which has already happened on one occasion.

In the event of a power failure, I'm estimating the UPS has only 10-15 minutes of power in it. There may be more but I don't want to automatically assume there is. This is enough to get through blackouts that last a few minutes or less. However, if the power is down for several hours I need the server to properly shut itself down automatically before the UPS power fails. This will hopefully keep the RAID integrity from getting hosed in those situations.

This sort of thing is easy on a laptop b/c it has built-in sensors to determine when it is running on battery power, but this server does not (as far as I know). I have an unusual network setup where my DSL modem is separate from my router. The router is also on the UPS, which allows me to SSH in through my laptop and shut down the server in the event of a power failure. Unfortunately, this only works if I'm there at the time to do it. I need a solution that always works whether I'm there to intervene or not.

Since my DSL modem is not on the UPS, it would go down with everything else if the power fails. I set it up like that deliberately because I have an idea about how to solve this problem: I was thinking of writing a script that would ping google.com or some other high-traffic/high availability site. If the ping completes successfully, the server would keep running. If the ping fails (because the modem is off), the script would think the power is off and would tell the server to shut down. I would add the script to Cron and have it run every 5 minutes. That would hopefully give the server enough time to shut down before the UPS runs out of power.

Before I go to the trouble of writing the script, I would like to know if there is a better way to do what I need. Thanks in advance for any help.

Source: (StackOverflow)

Is there a USB wall charger that "just works" with every device?


Almost every gadget today is charged over USB. It seems like a good idea since everyone has a computer with USB, but fumbling behind a computer and making sure that computer is on and does not sleep for the duration of the charge is a pain, not to mention you need to unmount drives and stop syncs as soon as your devices are plugged in.

USB wall chargers to the rescue! However, having gone through half a dozen different ones that all seem the same based on the back of the box, I have not found one that works with all my devices.

I have the following devices that I would like to be able to charge:

  • iPhone
  • XBox 360 controller
  • PS3 controller
  • Sony Reader PRS 350

These are all "normal" devices in that they (1) can be charged by being plugged into a computer without any additional software/drivers installed and (2) can even be charged by plugging them into some other device such as a network router, a printer, an AppleTV etc.

But I've had endless pains trying to find a USB wall charger that works with everything. The Apple wall chargers don't seem to work with any other devices and vice versa (unless you get one specifically marked as compatible with iPod/iPhone). The PS3 controller seems to reject almost all wall chargers, and worst of all is the Sony Reader which I have to date had 0 success with.

But all these devices work when you plug it into a computer or even a network router.



Does there exist a wall charger that (1) has enough circuitry to act as a USB host allowing all my devices to be charged and (2) is just a simple wall charger, not a big honking device that serves some other purpose and needs a big honking adapter?

Addendum: It's about how, not how much

Plugging the devices into my computer one at a time and profiling the USB, I see each draws this much power from the host:

  • XBox 360 controller - 500mA
  • PS3 controller - 500mA
  • Sony Reader - 500mA
  • iPhone - 1000mA

The iPhone uses more because there's some proprietary stuff going on between the Mac and iThings, but they charge fine with 500mA as well, just not as quickly.

All the wall adapters I've tried were rated to be at least 2A so should easily have covered any one of these devices individually from a pure power standpoint.

From my testing, it seems like the devices simply are not accepting any amount of power when only given it over the 2 power pins of USB. You need to either (1) short some pins in order to fool the device into thinking you're a wall charger made by the original manufacturer or (2) be an actual USB host.

(1) is the solution that most wall chargers provide since it's cheapest. The problem is the pin shortings required seems to be different for each manufacturer and it's impossible for any particular charger to cater to all of them.

(2) is what I'm looking for. It seems like there's some kind of handshaking that happens between a real USB host (like a computer or network router) that tells the device: you can safely charge. The problem is that based on what's written on the back of the box, there's no way to tell if a charger is (1) or (2), if a charger that provides (2) exists at all.

Source: (StackOverflow)

Will stopping hard disk when inactive also stop downloads?

If I enable to turn off hard disk when inactive in Windows Power Plan - Advanced Settings, will it also stop my downloads in different programs? Currently my Internet connection is slow.

Source: (StackOverflow)

Does installing larger RAM means consuming more energy?

Since every bit of a dynamic memory module needs to be refreshed to keep it's data, does that mean that if I install a module with more capacity than the current one on my laptop, more energy will be consumed?

And how big will the difference in energy consumption be?

Source: (StackOverflow)

What do you do when you're not allowed to turn off the computer (but must)?

We've all been there. You're installing a new major system for a client and you're finishing up with installing all required updates and this happens.

enter image description here
Image taken from petur.eu

Or, more specifically, this is the one I am seeing right now (sorry for the German):

Phase 3 of 3 - Configuring Windows - Please do not turn off your computer

The message is pretty clear. Do not power off or unplug your machine!

But I have been looking at this screen for 2 hours now and I begin to suspect that whatever is hidden behind it, failed.

So, what is the right thing to do in this case?

Source: (StackOverflow)