Does household voltage affect my OC?

[ryanbatc]

I've got an interesting issue going on and I think it's related to power - whether it be PSU, my UPS, or the voltage coming into my house from the power company, I'm not sure.

 

I live in northern MN and it's been extra cold this year.  I run a UPS with my rig because in the past we had short but frequent power outages (esp in the Winter).  The frequency of those seemed to have decreased in recent years but I kept the UPS anyway.  

 

Starting about 2 months ago my main PC would randomly reboot.  The frequency was about 1 per month.  But now I'm getting reboots more often (during testing today I had 3).  The software for my UPS says the line voltage coming into my house varies from 106 (lowest I've ever seen) to about 118v.  My question is how bad is this?  Is 106v enough to reboot my PC with its present OC?  I haven't done any official testing but from what I have done the system appears to reboot around 108-112v.  Sometimes my UPS does a BOOST and puts the voltage up to 122-124.  This normally happens under heavier load like when I'm playing BF4 or running IBT.

 

So known things:

 

1) My usual OC that I had in place for two years suddenly quit working (getting BSOD's 124 and 101 codes)

2) This Winter has been quite harsh temps averaged 5F (M15C) - line into house 106-118v (observed with power monitor)

3) I'm having two types of reboots 1 - PC reboots and loads back into Win7 ,  2- PC reboots/crashes to a BSOD resulting in 124 or 101 code.  With or without the OC type 1 reboot is happening.  Type 2 is related to my now failing OC.

 

Is there any power guru's out there (electricians too!) that can help me figure this out?  How can I methodically run through this stuff?  Is the lower voltage into my line affecting the stability of my system?

 

(edit: in case you guys are wondering why a low temperature outside would affect my computer....  I'm theorizing that all the people in my city are using their heat and appliances at times of the day where I'm more likely to reboot - evening)

[LHookins]

Random rebooting is generally caused by a failing power supply in your computer.  If it smells burned, replace it.

 

The UPS should be taking care of power variations.  Accent on "should."  Display the output voltage to see what it looks like, if you can.

 

Hook

[Indy511]

Time to replace the UPS battery?

Where I work I operate a digital printing press that had a UPS, the computer would shutdown for no reason. It turned out to be the battery.

[ryanbatc]

Both of those sound reasonable.  The PSU and UPS are about the same age...  3 years old.  (Not that long).  The PSU is Seasonic and usually those are known for excellency.  The UPS is a Ultra 1000VA like this

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=770423

[Need-To-Know]

You can get a PSU tester for cheap.

[ryanbatc]

Yeah that's on order from amazon too....

 

I've got a neat flow chart for this kind of stuff.  It's just a waiting game now but I was wondering if anyone had any opinions too.

[LHookins]

Ryan, I've had 4 burned power supplies.  See if you can sniff the power supply.  If it smells burned (it'll be obvious), it needs to be replaced.  How did I get so many burned PSUs?  Well, the wizards at PowerSpec put in cheap power supplies that failed at almost exactly one year.  My last computer I preemptively had them install a better power supply before taking the computer home and it's still working 2 years later.  You'd think I'd quit buying that brand.

 

I've also had a UPS battery totally die.  The only indication was when the power failed for a second and the computer shut down.  This will depend on the design of the UPS.  If you lose power for a while and you computer still runs, the UPS battery should be good.  You should be able to check the remaining up time on the UPS somewhere.

 

Hook

[Noel]

Yeah that's on order from amazon too....

 

I've got a neat flow chart for this kind of stuff.  It's just a waiting game now but I was wondering if anyone had any opinions too.

Hey Ryan,

I have a 6 mo old Corsair HX 850W Professional for sale if you can possibly use it.  I want to SLI and need a tiny bit more headroom to accommodate it.  Let me know if you're interested if you have to replace yours and don't wish to buy a new one.   I have a fabulously stable system and I'm sure the PSU plays a part in that.

[Luc Brusselmans]

Ryan,

 

The answer is by al means a big YES.

The answer is in fact quite simple.

All power supplies are built to work at a certain 'weet spot' voltage.

For Belgium this would mean a voltage of 210 to 230 volts.

I worked for a high-end hifi dealer and experienced quite a few times that

high-end cd players (price range of 6000 USD or more) would just stop working

or skipping tracks when the voltage dipped below 205 volts.

This occured at night, with everybody in the street at home was turning on all kinds of electrical equipment.

 

I would not be surprised that your stable OC (which greatly depends on the voltage available to the CPU)

would become unstable because of lack of power.

Especially when the powersupply is rather weak or working at its limits.

It could be failing of course but you assuming it is the houshold voltage can be correct too.

 

Luc Brusselmans

Belgium

[Humpty]

Bring the OC down to default and test.

[martin-w]

Mains supply, UPS, PSU... could be either of them I say. Without testing, or swapping them out it's hard to say which.

 

Could also be the CPU. After overclocking for a while it's feasible you  require higher CPU voltage as a degree of degradation sets in.  Far more likely to be PSU, mains or UPS though.

[JRBarrett]

If your mains voltage is indeed dropping all the way down to 106 volts, that can definitely be an issue. Most electric utilities aim to regulate the voltage supplied to residential customers to within +/- 5 percent of the nominal value - which in the US is typically 240/120 volts. So any voltage higher than 126, or less than 114 would be considered out of acceptable tolerance.

 

Purely resistive loads, (like light bulbs, electric heaters, toasters, stoves etc. can have their life shortened by voltages that are consistently too high, but the only adverse affect of low voltage will be a loss if efficiency.. i.e. lights will be dim, or heating elements won't get hot enough.

 

Electric motors and regulated power supplies on the other hand, can be permanently damaged by low voltage. In both cases, the current consumption will go up as voltages fall. In the case of motors, this can lead to overheating of the windings in the motors. Switching power supplies, like those found in computers, will also overheat at low voltages, and below a certain threshold, their ability to control the voltage outputs on the 5 and 12 volt rails will be lost, which can definitely lead to reboots, (or worse). The situation is worse at a high OC, or in a system with a high load - multiple hard drives, high-end video card(s) etc.

 

You are probably correct in your theory that the low voltage is due to high heating loads in your city, but you should probably bring the matter to the attention of your local utility company, as a voltage dropping below 110 volts consistently is NOT normal. There are many factors that could be at the root of the problem. It could be something local to your immediate neighborhood - like a failing step-down transformer that supplies your home, (and likely the homes of several of your immediate neighbors) or it could even by a problem at the substation that serves an entire district of your city. I'd tend to think the problem is relatively close to you, since most utilities monitor the high voltage output circuits of their main substations pretty closely, and would be immediately aware of a sustained under voltage situation at that point in their network.

 

Utilities often use banks of capacitors in neighborhood distribution circuits which are supposed to switch into the circuit automatically when system voltage drops, in order to boost the voltage back to acceptable levels. Very possible one of these units is malfunctioning due to the extreme cold. Since these voltage-boosting capacitors only affect limited areas of the overall network, the utility often won't know there is a problem, unless customers call to report low voltage situations.

[Kattz]

All power supplies, if rated and marked by CE/CSA/UL/TUV, should always handle an incoming spec voltage +/- 10%.  In Ohio, I've had voltage as low as 98VAC, and Japan is 100VAC normally.  My rig has ran in Japan and in Ohio with severe OC's (up to 60% OC) and no issues.

 

a)  your PS is possibly shot, OR

 b )you have a video card or CPU cooler fan that is running slow or locked up.  I had the same issue as you, actually the exact same issue as you, and it was a fan on one of my ATI cards in my Crossfire setup that was ok until the card got warm and then the fan was dropping down to almost no RPM.  The card would overheat and then the computer would just <blip> off.  No warnings, no errors, no BSOD.  Found the problem quite by accident after replacing a perfectly good PS and the problem persisted.

[LHookins]

 

 

The card would overheat and then the computer would just off. No warnings, no errors, no BSOD.

 

Overheating will typically turn the computer off.  Bad power supply will definitely make the computer reboot.

 

Hook

[ryanbatc]

Just in case I checked for malware/viruses - none.

I also memtested the ram on boot and 0 errors.

 

I lowered my OC to 4.2Ghz and it appears stable now.

 

I may have had two issues, my OC failed and random reboot.  Maybe the reboot WAS OC related?  Maybe not though because the reboot happened with stock clock settings too.

 

More testing and waiting for my psu test tool.  No odd smells from the PSU.

 

For the UPS, the battery seems fine I did a self test and it sustained the PC fine.

 

I ran Furmark for the GPU stress test... went to 85C at about half fan rpm.  That's usually what the temp is with BF4 (usually a little less).

 

Power levels haven't dropped below 112v today.... still low but it's dang cold and we heat the house generally warm with two young kids.