Cablemod extension kit and inline capacitor

[darkrose]

I am thinking of getting an extension kit and was wondering if I would still get the same benefit of reduced ripple and noise etc... using extensions with the original cables to just using the original cables. I read that you get less performance the further the capacitor is from the connector. Is there any cons using extension and according to cablemod they're compatible with all psu is that true?

 

CPU: Ryzen 2600x

Motherboard: Asus x470 gaming-f

GPU: EVGA 1070ti

Ram:16gb g.skill

PSU: corsair RM850x

[Arika]

they are extensions and should only ever be used as such, they are not replacements for the original cables 

 

8 minutes ago, darkrose said:

I read that you get less performance the further the capacitor is from the connector

performance loss with be fractions of nothing

 

10 minutes ago, darkrose said:

Is there any cons using extension

Cablemod has been in business for a long time, they wouldn't exist if there was major downsides to using extensions

 

[mariushm]

The inline capacitors can be removed completely, they're optional.

The improvements they bring are very small, improving something that's already way better than the maximum allowed (for example if something can go up to 100% and still be valid atx power supply and 0% means ideal, impossible, the power supply without capacitor is at something like 20%and with capacitor it's maybe at 15%).

Adding extension would maybe bring the quality to around 25%

 

For your system, where that capacitor is and even if it is or not, makes no difference.

[darkrose]

12 minutes ago, Arika S said:

they are extensions and should only ever be used as such, they are not replacements for the original cables 

Maybe I didn't word it correctly but I meant to say was do I still get the same benefit using original cable vs extension+original.

[darkrose]

23 minutes ago, mariushm said:

The inline capacitors can be removed completely, they're optional.

The improvements they bring are very small, improving something that's already way better than the maximum allowed (for example if something can go up to 100% and still be valid atx power supply and 0% means ideal, impossible, the power supply without capacitor is at something like 20%and with capacitor it's maybe at 15%).

Adding extension would maybe bring the quality to around 25%

 

For your system, where that capacitor is and even if it is or not, makes no difference.

I'm confused, without capacitor 20% and with is 15%? Are you saying I get less improvement with capacitors?

[mariushm]

I was thinking of 100% as maximum permitted "noise", "badness" ... 0% is ideal perfect DC output, impossible to achieve in real world.  15% with capacitor very close to the connector, 20% without capacitors. If you add extension, you'll maybe degrade to 22-25% quality.

So yeah, the other way around ... 0 is best, 100 is worst.

What I was saying is that majority of power supplies out there from brand names are somewhere at 40% or less... Your power supply, with or without capacitors is already at around half of that, and your computer components were designed to account for the fact that someone may use a shitty power supply that has way worse power quality.

 

The capacitors at the end of connectors don't really improve performance in day to day use. They make a difference only in extreme scenarios where you would overclock the processor really high... the presence of the capacitor may give you an extra 25-50 Mhz when you're overclocking, but even that is debatable.

 

Corsair most likely put the capacitors on the power supply simply because other manufacturers were installing capacitors on their power supplies and they didn't want to see online reviews saying "no capacitors on cables" as a negative conclusion of the review.

It's also a  "stupid buyer says this psu has capacitors on cables and this one doesn't and he'll go for the one with extra bits, so we also have to put capacitors to not give the others an edge over us"

[darkrose]

6 minutes ago, mariushm said:

I was thinking of 100% as maximum permitted "noise", "badness" ... 0% is ideal perfect DC output, impossible to achieve in real world.  15% with capacitor very close to the connector, 20% without capacitors. If you add extension, you'll maybe degrade to 22-25% quality.

So yeah, the other way around ... 0 is best, 100 is worst.

What I was saying is that majority of power supplies out there from brand names are somewhere at 40% or less... Your power supply, with or without capacitors is already at around half of that, and your computer components were designed to account for the fact that someone may use a shitty power supply that has way worse power quality.

 

The capacitors at the end of connectors don't really improve performance in day to day use. They make a difference only in extreme scenarios where you would overclock the processor really high... the presence of the capacitor may give you an extra 25-50 Mhz when you're overclocking, but even that is debatable.

 

Corsair most likely put the capacitors on the power supply simply because other manufacturers were installing capacitors on their power supplies and they didn't want to see online reviews saying "no capacitors on cables" as a negative conclusion of the review.

It's also a  "stupid buyer says this psu has capacitors on cables and this one doesn't and he'll go for the one with extra bits, so we also have to put capacitors to not give the others an edge over us"

Thanks for the clarification. Why would I get less quality with extensions+cable with capacitor compared to only using cable without capacitor? Wouldn't the extension+cable be somewhat better than having no capacitor at all.

[Arika]

1 hour ago, darkrose said:

Maybe I didn't word it correctly but I meant to say was do I still get the same benefit using original cable vs extension+original.

any difference in performance between using the extenders or not is going to be negligible at worst and non-existent at best

[mariushm]

Because wires are not ideal things, they have physical properties like resistance and inductance which affect things.

Anything you add to the cable will affect things negatively, but it's small enough percentage of degradation that it's not worth wasting time thinking about.

The capacitor is not a placebo, it does improve the quality of the power, but in a very small amount, improving something that's already very good. However, the improvements are the biggest the closest that capacitor is to the end connector. If the capacitor is further away, the effects of having the capacitor diminish. There's still some benefit, but very small.

 

If you want to be technical it's like this:

The resistance of the wire causes some voltage losses (you have exactly 12v at the connector of the power supply, but you may have 11.99v at the other end, because the wire resists a bit and some voltage is lost, and the wire heats up a bit.

The inductance is a natural property of any wire and basically resists high fluctuations of current, think of it like when the processor does nothing consuming only 10 watts and suddenly you start a movie or something and the processor starts crunching numbers and suddenly demands 50 watts. If those 50 watts have to reach within some nanoseconds at the other end, too high of an inductance can be bad because inductance basically resistance sudden changes.... it's like a spring, it gets smaller or bigger but it takes some effort to change it's size. For day to day use, even for regular overclocking, the inductance in wires is small enough that it can be ignored. 

If you're extreme overclocker and you're overclocking processors to the point where processor can go between consuming 30 watts and demanding 100-150 watts the very next moment, in such scenarios the inductance can be big enough to make the electricity arrive too late and that can make the processor unstable. By adding a capacitor by the connector, when the processor wants suddenly a lot of power, the capacitor can give that power for a few nanoseconds until the wire's inductance stops hampering the power delivery and does its job ... so the end result is that an overclocker may see he/she is able to get 25-50 Mhz more overclocking at the extremes.

So if you add an extension cable, the capacitor still does its job, improving the power delivery by some very small amount up to where it is, but from that point to the end of the extension you have inductance again and you have resistance of the wires, so that degrades quality a tiny bit.

 

Longer wires and extensions are bad because of the extra resistance added.

You have the resistance of the wire itself, at around 0.021 ohms per meter if AWG18 wires are used, and you also have the resistance at the point where two connectors meet, which is around 0.01 ohm (because no contact is perfect).

So you have some loss where the modular cable is plugged into the power supply, there's some loss in the original cable, then there's some loss at the point where the extension cable meets with the original cable and then again some loss in the cables of the extension.

If you use the Ohm's law  (Voltage = Current x Resistance) you can estimate how much losses you'd have.

Let's say you give 120 watts to the processor, through 4 pairs of wires (the 8 pin EPS connector) which is a cable 1 meter long, but you add an extension that's another meter. 

120 watts at 12v is 10A, so considering there's 4 pairs, that means 2.5A per pair. The total length of the wire will be 2 meters from power supply to the end of extension, and 2 meters back to the power supply, so 4 meters in total.

So if the power supply outputs 12v, then you'd have at the end of your extension :

V =  2.5A x  ( 4 meters of wire x 0.021 ohm per meter + 0.01 ohm resistance at psu connector + 0.01 ohm resistance where the extension connects + 0.01 ohm where its plugged into psu)  = 2.5 x 0.114 = ~ 0.285v

So at the end of the cable, you'll only have around 11.8v

 

Now, the processor doesn't really care, because you have the VRM (the dc-dc converter) which takes this voltage and converts it to 0.7v..1.4v the processor needs.