PSUs and UPSs

[oleguy]

I remember years ago a big concern with computers, especially with high-end and overclocking, was that the power coming out of the socket was dirty (not exactly 50 or 60Hz). Between that and places where brownouts were common (either a localized or a regional issue), the advice was that one should invest in a power conditioner with voltage and current regulation. Some consumer products would offer such functionality combined with other things, like a UPS, or so they claimed.

Fast forward to today, and many PSUs advertise things like over and under voltage and current protection and promise "clean and stable power", which I'm making an assumption has meaning in that when combined with the other protections, it ensures a clean feed between PSU and MB, GPU, drives, etc.

With the SSD craze, sudden power loss can be a bit of an issue if you are in the process of doing almost anything. I have had a few outages, but they've typically been when the computer was idle, so I didn't see any data loss. However, my Win7 install has gotten flaky since the last sudden outage, which makes me wonder. It also looks like some people have the SSD vanish from to OS after sudden power loss, to the point that Crucial has a troubleshooting procedure for dealing with the issue.

As such, I've been thinking of getting a battery backup, but again see the basic ones, plus the ones that add in power conditioning and the like. With a modern PSU, is much of that necessary? Or are PSUs not really that great at power regulation and if you have such a concern, it's really best to get a UPS with built-in power regulation? Or do the UPS claims even lack validity?

 

[Blain]

To give my PS's every chance at a long and healthy life, I always run my PC's behind a good AVR UPS.
My HTPC and 42" LG are supplied by a CyberPower 1500AVRLCD, with my main PC & 24" Dell fed from a CyberPower CP1350AVRLCD.
My main goal is clean power flowing to the components.
It was an added benefit that I was able to keep watching an NFL game last year when the power went out.

 

[Torn Mind]

You are confusing power out of the socket vs power out of the connectors. PSUs have no control over what the wall electricity will be like, but they are responsible for converting it to DC, filtering the direct current output, and regulating the output DC voltage, according to the basic block diagrams floating on the Internet. So, it is indeed the case that PSUs won't be doing any "conditioning" before the electricity gets to the rectification stage of the PSU.

When dirty mains voltage is being talked about, it is how un-sine wave it looks like and how voltages are not within the ~120 V that should be delivered.
Unclean output current from a power supply could mean various things, such as ripple and noise exceeding the ATX spec or the voltage output is inconsistent.

For SSDs, they can become corrupted if the power is shut down while making a write. That is why an array of capacitors are on the Crucial M500 and Intel 335 SSDs. The safest regulation is on the SSD itself. http://forums.anandtech.com/showthread.php?t=2228071
The other devices are useful though.

 

[oleguy]

You are confusing power out of the socket vs power out of the connectors. PSUs have no control over what the wall electricity will be like, but they are responsible for converting it to DC, filtering the direct current output, and regulating the output DC voltage, according to the basic block diagrams floating on the Internet. So, it is indeed the case that PSUs won't be doing any "conditioning" before the electricity gets to the rectification stage of the PSU.

When dirty mains voltage is being talked about, it is how un-sine wave it looks like and how voltages are not within the ~120 V that should be delivered.
Unclean output current from a power supply could mean various things, such as ripple and noise exceeding the ATX spec or the voltage output is inconsistent.

For SSDs, they can become corrupted if the power is shut down while making a write. That is why an array of capacitors are on the Crucial M500 and Intel 335 SSDs. The safest regulation is on the SSD itself. http://forums.anandtech.com/showthread.php?t=2228071
The other devices are useful though.

Thank you for the response, as that clarifies what I was trying to ask and gives me a better way in which to ask it. As the PSU is responsible for the AC to DC conversion, it is at the mercy of what's coming out of the wall. What I see today when looking up PSUs is marketing about protection against over and under voltage and current situations.

So maybe the better question is this: Does a typical AC source really need to be conditioned before it hits the PSU, since the PSU is designed to handled a range of voltage and current input and deliver a consistent DC feed? If so, are there really any consumer-grade UPS systems that actually accomplish enough to actually make a difference? Or would the more usual surge protector with stand-by battery backup be just as good? I'm not looking to pay for total isolation from the mains, just something to ensure my PSU doesn't croak before its time.

I'm in new construction in an old neighborhood, so while my house doesn't seem to have issues with brownouts, the above-ground powerlines have been visibly prone to tree damage and arcing off during storms. In the three years I've lived here, we've had a dozen outages lasting more than 5 minutes, including one this past summer that was upwards of 3 days for my neighbors. We've also had at least a dozen times we've come home where the clocks are flashing. Not the most reliable power delivery system, it seems. I have no idea what the sine-wave that comes out of the wall looks. My brother took his ocilliscope with him.

 

[thedosbox]

I'm in new construction in an old neighborhood, so while my house doesn't seem to have issues with brownouts, the above-ground powerlines have been visibly prone to tree damage and arcing off during storms. In the three years I've lived here, we've had a dozen outages lasting more than 5 minutes, including one this past summer that was upwards of 3 days for my neighbors.

For that reason alone, get a UPS. It will at least allow you to ride out a short outage, or shut down your system cleanly without risk of data loss.

 

[Torn Mind]

Thank you for the response, as that clarifies what I was trying to ask and gives me a better way in which to ask it. As the PSU is responsible for the AC to DC conversion, it is at the mercy of what's coming out of the wall. What I see today when looking up PSUs is marketing about protection against over and under voltage and current situations.

So maybe the better question is this: Does a typical AC source really need to be conditioned before it hits the PSU, since the PSU is designed to handled a range of voltage and current input and deliver a consistent DC feed? If so, are there really any consumer-grade UPS systems that actually accomplish enough to actually make a difference? Or would the more usual surge protector with stand-by battery backup be just as good? I'm not looking to pay for total isolation from the mains, just something to ensure my PSU doesn't croak before its time.

I'm in new construction in an old neighborhood, so while my house doesn't seem to have issues with brownouts, the above-ground powerlines have been visibly prone to tree damage and arcing off during storms. In the three years I've lived here, we've had a dozen outages lasting more than 5 minutes, including one this past summer that was upwards of 3 days for my neighbors. We've also had at least a dozen times we've come home where the clocks are flashing. Not the most reliable power delivery system, it seems. I have no idea what the sine-wave that comes out of the wall looks. My brother took his ocilliscope with him.

Overvoltage, overcurrent, etc situations can occur in the PSU. The PSU that claim to have those protections should have integrated circuits that detect overvoltage, overcurrent, short circuits, etc to protect from fires and/or damage to the equipment. The overvoltage protection should shut the PSU down if the voltage on a certain rail goes way beyond the ATX spec. For the 12v rail, if the voltage goes over 15.6 V, overvoltage protection should kick in and shut off the unit. Obviously, 15.6 is very high, and won't save a CPU being fed 14 V.
More info about protection circuits here: http://www.hardwaresecrets.com/prin...ed-to-Know-About-Power-Supply-Protections/905


A line conditioner insures a AC proper waveform. Oftentimes, a line conditioner does voltage regulation makes sure the voltage does not tread far away from the acceptable range around 120 V.

In your case, I think a UPS is a major priority for you, since the sudden power loss can cause more damage(and maybe already done so) than a brief spike or surge in voltage, or a slightly imperfect waveform. You PSU is still okay, but with SSDs, those sudden cuts in power is a possible ticket to making the SSD a brick. If your lights dim when a machine starts up(i.e refrigerator), a UPS with a automated voltage regulator like Blain mentioned is worth a buy. Simulated sine wave output should be the bare minimum for electronics equipment though; UPS that out square waves on battery backup are something I personally feel iffy about connecting a computer or HDTV to.

A line conditioner insures a AC proper waveform. Oftentimes, a line conditioner does voltage regulation makes sure the voltage does not tread far away from the acceptable range around 120 V. In your case, I don't think it is as big of a priority as good UPS with voltage regulation. They do cost a pretty penny, but if it fits your budget, they are worth considering.
http://www.apc.com/products/family/?id=310

Also, if the weatherman says a storm is coming, do disconnect everything from the wall when feasible since lightning still can damage equipment connected to the wall.

http://en.wikipedia.org/wiki/Power_conditioner
http://www.sweetwater.com/insync/power-conditioner-voltage-regulator-ups-differences-explained/