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I'm looking through the marketing information for my motherboard, and noticed an odd statement regarding the lifespan of their Nichicon 12K Black Caps.

"Supreme 12K black capacitors with lifespans of at least 12,000 hours [emphasis added]. Compared to other counterparts on high-end motherboards that merely have lifespans of around 10,000 hours, ASRock applied Nichicon 12K Black Caps that offer 20% longer lifespans and provide more stability and reliability."

Source

12,000 Hours = 500 Days = 1.37 Years.

This can't mean that the total powered on time for the PC is expected to be less than a year and a half, can it? It certainly wouldn't be something I'd prominently highlight in my marketing material.

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    Doesn't "20% longer" sound a lot better than "not quite as crappy as some others"? – fixer1234 Feb 16 '18 at 23:26
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    Agreed, but I have boxes with high-end boards I built 10 years ago that are still fit for daily use (back when Abit was still in the picture). I'm just having trouble mapping this statement to reality. – Frank Thomas Feb 16 '18 at 23:29
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    @FrankThomas: "lifespan of at least 12,000 hours" doesn't mean it gets to 12,000 hours then stops. It means if it stops before 12,000 hours then it is treated as a quality control problem. My TV's manufacturer's warranty lasted I think 12 months? I've had it for 15 years. Now of course lifespan and warranty aren't the same thing, but the principle is roughly the same.. – Lightness Races in Orbit Feb 17 '18 at 1:37
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    Might be a question for Electrical Engineering Stack Exchange. Also see the Capacitor Plague, where Japanese capacitors were a selling point. It was a big deal back in the 1990s. – jww Feb 17 '18 at 5:33
  • 1.37 years MTTF would be a terribly unreliable mainboard. For comparison: Server mainboards more often than not will make 10 years intact - though they use somewhat more strictly selected components and are subject to better cooling discipline (see what is said about temperature...). – rackandboneman Feb 18 '18 at 21:59
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Im not a expert in this area, but look at available info.

  1. Lifespan is temperature related.

lifeactual = lifebase × temperatureFactor × voltageFactor × currentFactor

lifeactual is the life expectancy at the operating temperature, voltage, and current.

lifebase is the life expectancy at the rated temperature, voltage, and current temperatureFactor : For both Al e-caps and film capacitors, a 10oC decrease in temperature results in a doubling of life expectancy. So the temperature factor is 2**(0.1*(Tm−Tc)) . Where Tm is the rated temp and Tc is the operating temp.

voltageFactor is the derating due to the operating voltage being lower than the maximum rated voltage. According to United Chemi-Con, voltage has far less of an effect than temperature on the lifespan of an Al e-cap (unless the voltage is exceeding the rated maximum)

currentFactor is the derating due to the operating current being lower than the maximum rated current. Current has a more significant effect on Al e-caps than film capacitors because of their higher equivalent series resistance (ESR). The power loss due to the ESR will be equal to I2capRESR and all of this power loss leads to self heating which will affect lifespan.

  1. It voltage and current related.

Calculating the Lifespan of Electrolytic Capacitors with De-Rating

So based on it you can multiply lifespan in times (4x - 8x)

And avoid overheat. Cool PC - long living PC.

But really, capacitors one of most dying components.

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    Good link. Its now clear to me that the measurement is likely very conservative, compared to my daily use-case, and that lifetime hours likely do not represent real-world powered-on hours. – Frank Thomas Feb 16 '18 at 23:45
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This is an attempt at marketing that fails due to oversimplifying an engineering issue until it actually means the opposite of what it's supposed to mean. And this question is all over the internet...

As explained by the others, capacitor lifetime depends on temperature. I picked a random datasheet (Nichicon R5), this is the "endurance" spec:

Test condition      105°C, rated voltage 2000Hrs.
Capacitance change  Within ±20% of initial value before test
tan δ               150% or less than the initial specified value
ESR                 150% or less than the initial specified value
Leakage current     Less than or equal to the initial specified value

This means the manufacturer guarantees that after a number of hours at a specific temperature, the important specs (capacitance and ESR) will not degrade by more than -20% and +50% respectively.

It doesn't mean the cap pops off or stops working completely, it simply degrades. If the application does not require the full performance of the capacitor, then it may work fine for a much longer time. For PC mobos this is not the case, high performance caps are required on CPU VRM, especially ultra low ESR due to the huge ripple currents involved. ESR is equivalent series resistance, and it will increase as the capacitor gets old or if the electrolyte dries out, which makes the capacitor heat more (due to resistive losses) and perform worse at its supply voltage smoothing role.

This is different from the well known "capacitor plague" which was due to a faulty electrolyte formula. In this case the capacitors did not honor their lifetime specifications, they were defective products which are no longer manufactured.

Now, Alu-polymer caps rated for 12k hours at 105°C are very good quality components, some of the best available. Usually you would get 2k hours 105°C caps, so Asrock is selling a good product with dumb marketing.

However it doesn't matter at all. Using the lifetime estimation from Illinois Capacitors that Tim posted, at 60°C (which is already very hot for a mobo, time to clean the dust!) the polymer 2000h/105°C cap would last 40 years already, and the 12000h cap would last two centuries. Temperature has a huge influence!

So, yeah the 12k hour caps are a nice touch but they're a bit of a luxury. 2k hour 105°C caps would still work fine when the computer becomes obsolete and is replaced. Especially since the 60°C temp I used is quite pessimistic, the caps should be much cooler than this unless you run high cpu load 24/7 and the airflow is terrible. So, no planned obsolescence here.

The caps that are accused of "planned obsolescence" and die are usually the ones which are inside consumer electronics power supplies, right next to a very hot heat sink with low airflow, they're run close to max spec and aren't polymer caps but rather low-Z alu electrolytics which are more vulnerable to heat. If the manufacturer puts a crapxon brand 85°C-rated cap in there, yeah it's gonna go "planned obsolescence" pretty quick. Also the caps on the HDMI board in a buddy's AV receiver, all 85°C caps next to a big hot CPU with no fan and no airflow, this receiver is famous for this, all the caps always die. This is more of a design mistake or excessive cost-cut than planned obsolescence though.

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    The aluminium/polymer caps have to be right next to the VRM power MOSFETs for proper decoupling, and all this has to be right next to the CPU. They sit in the airflow from the cpu fan though, which cools the FETs, inductors, caps, etc. Check a board pic this is the only place they can be. Impressive VRM by the way, 12 phases with excellent MOSFETs too! Well, that's needed for >120 amperes at 1.2 volts... – peufeu Feb 17 '18 at 22:32
  • Anyway, in the last paragraph I was referring to the caps in switching power supplies (like in a LCD TV) where you will usually see a cap right next to the hot heat sink of the switching transistors, again this is due to layout constraints so it is hard to avoid, but it shortens the cap lifetime a lot... – peufeu Feb 17 '18 at 22:32
  • @peufeu No, not really. 4 or 5 phase would be more than sufficient at that amperage level; 12 phase is just overkill and wasted board space with modern parts. If anything it tells me the manufacturer is using lower rated and inferior parts, not top of the line high rated parts. Or you're looking at 300+A, not ~120A at 1.2V.... – madscientist159 Feb 18 '18 at 10:29
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    It's a 300€ mobo (!!!!!!!!!) for overclocking fanatics, at this insane price level it better be overkill and dipped in snake oil for that extra 1% performance boost!... check out the bunch of shiny golden caps "for better sound" near the audio chip... – peufeu Feb 18 '18 at 10:43
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This really depends on the type of capacitor, and there are many factors involved.

Max Temperature Rating
Ambient Temperature Rated Voltage (in Volts DC)
Applied Voltage (in Volts DC)
Rated Ripple Current (mili-amps/Amps)
Applied Ripple Current (mili-amps/A)
Part Rated With Ripple (percentage)

Each individual type of capacitor is measured differently.

(Radial / SMD / snap-in) enter image description here

(Polymer type Capacitors) enter image description here

(Super-Capacitors) enter image description here

(Axial aluminum electrolytic type Capacitors) enter image description here

(Film type Capacitors) The operating conditions affect the life of a film capacitor in a close way to aluminum electrolytic capacitors. Voltage de-rating has a greater effect on the life as compared to an aluminum electrolytic capacitor. enter image description here

(Ceramic type Capacitors) enter image description here

"Planned obsolescence, or built-in obsolescence, in industrial design and economics is a policy of planning or designing a product with an artificially limited useful life, so it will become obsolete (that is, unfashionable or no longer functional) after a certain period of time. The rationale behind the strategy is to generate long-term sales volume by reducing the time between repeat purchases (referred to as "shortening the replacement cycle")."

The company advertising that 12,000 hour rating just may be a case of Planned obsolescence, or built-in obsolescence.

i would want to blame the design engineers, but I am sure it wasn't even their fault. Companies seem to have no shame at all anymore engaging in this behavior, and it doesn't seem to me like a good business plan to advertise you are essentially "shortening the replacement cycle".

references:

https://en.wikipedia.org/wiki/Planned_obsolescence

equations taken from illinoiscapacitors.com, where you can also find nifty calculators for the equations mentioned above. http://www.illinoiscapacitor.com/tech-center/life-calculators.aspx

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    Planned obsolescence for capacitors is nonsense. Just like lipo batteries, the chemistry is complex and does age, things can't be perfectly sealed and leak etc. And the more you do against it, the more you have to pay. Nobody would pay the price for a mobo that uses capacitors that cost 2€ a pop. – PlasmaHH Feb 17 '18 at 20:42
  • I guess you say that for the same reasons they have a shelf life... – PlasmaHH Feb 17 '18 at 21:40
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I don't know what the specs of those exact capacitors, are but research has shown it is also temperature related.

Its 12k at a specific temperature, and the lower the operating temperature is compared to the rated temperature the longer they will last.

Cheap capacitors can be rated at 50C or less, and good one 70C possibly more. 50C can be a real problem is the case isn't properly ventilated. If you have a house without air conditioning, your case is cramed into a poorly ventilated area, and the air flow incase is bad.

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  • I'm guessing, just from what I'm seeing online, that they probably baseline from 85C, but I don't know what the average operating temp of a capacitor in a box that's used (perhaps heavily) 8 hours a day in a room temp room, in a box with reasonably aggressive active air cooling. Either way, its looking like there is definitely room for interpretation and that their testing is beyond what my rig would encounter in daily life. – Frank Thomas Feb 16 '18 at 23:42
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My P5Q Pro states

100% High-quality Japan-made Conductive Polymer Capacitors! VRM 5000hrs lifespan @105°C, (208 days) ( 500,000hrs @65°C (57 years)

I'm still using it after 10 years as my primary computer, 50% oc'd for over half of its life using core2 duo. Two years ago I updated this LGA775 with a hard mod & O/C'd Xeon quad core 5400 & added a heatsink to the mofsets. Bear in mind that a high quality PSU is CRUCIAL for longevity as well. Last I checked (a couple years ago) you can't get better than Seasonic.

Z370 states 12000hrs, 105°C (1.36 years or 500 days)

12000hrs at @105°C, translates to 1,188,000hrs at 65°C (135.6 years) using the same scale as the 10 year old P5Q Pro. Other factors may come into play given the the fact these new capacitors are over twice as reliable. Asrock would have done well advertising with a lower temperature as well!

And as a bonus my P5Q Pro comes with Intel ME [major hardware security threat] disabled, and its as easy to disable on the Z370 TaiChi as installing this

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