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gpu-psu capacitor?

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NErdgOd56

New Member
Joined
Nov 5, 2018
i was thinking about hooking up a 12v capacitor (like one from walmart for subwoofer amps) in line with the 8pin gpu plug. ive used them with solar pannels and such and they def help a bunch.

ive got a few hard drives and such drowing a lot of power. i also have a secondary gpu i use for linux, and im trying to avoid buying a psu whil also having a capacitor in my computer because that would impress my friends and be badass imo.

im just worried about things like wire gauge and if the extra energy would damage any components at idle or something. any one got any advice (and by advice i dont mean "dont do it" lol if you have a reason i shouldint pleas give a little bit of detail so i can google)

id probably by a fuse and i was thinking of ordering some high amp diodes? i have a pi in my rig( to control leds and such) in case i need to like detect shutdown and trigger a relay or something. im willing to put work into this to make it work, as long as it shows results ( i get a throttle cap reason: pwr or whatever in gpuz constantly)
 

EarthDog

Gulper Nozzle Co-Owner
Joined
Dec 15, 2008
Location
Buckeyes!
Welcome! A couple of things...

1. Please list system specs including cpu, memory, ram, mobo, and power supply so we can see if what you have (psu) will work.
2. Wire gauge is the least of your worries. Thinking adding a capacitor inline will get you more power, is. It doesn't work that way and wont yield the benefits you believe you will receive. It is for additional ripple protection.
3. Its not really impressive or badass to ng have a cap inline. Some power supplies come this way, some dont. But I wouldn't call it a bragging point.
 
Joined
Dec 13, 2005
Is there a legit reason for adding the cap? Sounds like it's just to offset some of the load, in which case - you do realize that recharging it will also put strain on the PSU right?


Like ED said, specs would help. If you're seeing any sort of instability going with a beefier/higher quality supply from the start really is the best bet. If you want a flashy side project there are tons of little LED voltmeters and ammeters out there. You can slap one on some old capacitors and rig it up so it simply looks like your PC is running off this giant bank but with less risk.
 
OP
N

NErdgOd56

New Member
Joined
Nov 5, 2018
good point yall, should have mentioned my specs, but i was really just looking to see if anyone had killed a gpu trying this. ill have to get the psu model and specific wattage tomorrow, but its between 750 and 850w, i dont remember it off hand, but i have a watercooled (slightly)overclocked 1070, oc'd, ryzen 1500x also watercooled (both single radiator aio with two fans (push-pull)) 16gbram, ocd as well, theres also a gt730 and an asus ac wifi card, and all of my satas are used (5hdds, no ssd) including one m.2 sata. with one extra fan and a bunch of usb devices, two keyboards, two mice, sometimes a steeringwheel and/or joysticks/pads. furthermore theres an rpi3 controlling ws2812b LEDs (12v) , somewhere around 70-90 of them.

additionally
i run two OS's when im using one virtual "system" at full load and one idle its fine, if all "8" cores and both gpus are being used,for instance gaming on windows "system" and video transcoding on linux. or compiling something, the cards and the cpu start to throttle and gpuz and hwmonitor shows definite "rippling." now that i have a term for it.

and to put icing on the cake: the ac power source is unstable, to the point where ive already gotten a ups and set it up where i mainly use the pc to stop random shutdowns, ps its in a shed a good bit away from the main house.

i already have a capacitor, and i dont like buying new parts when my current parts arent broken, especially with my current budget. i already have the capacitor and have already spent money on a ups. if i can get this to stabilize the main power hog in my system which is the 1070 then i think id be golden, ive already tried using it for the leds and i still get pwr throttles. im just wondering if the cap, in theory, could damage the card somehow? it was way less expensive than gpus are now than when i bought it and i DEF would have to buy something smaller if i break it..

does anyone have a hard "do not do this becasue it could ____ your ____!!!111" reason not to do this? im prolly gonna keep checking this for about a week and then try it if no one says anything lol

3. Its not really impressive or badass to ng have a cap inline. Some power supplies come this way, some dont. But I wouldn't call it a bragging point.

1) says you
2 youre thinking like, tiny small black caps. i mean something like this:
to my normie friends theyd be all like WHAT THE FUDGE only they wouldnt have said fudge granted mines not that flashy and big, but itds beep when filled and light up during heavy use.
 
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Johan45

Benching Team Leader Super Moderator
Joined
Dec 19, 2012
If the AC is unstable a decent UPS should help with that. Next is your PSU if it's unstable that's a problem for the whole system. A 7-850 W "quality" PSU shouldn't even break a sweat running all that you have connected, I do wonder why the gt730, that's just a waste of power considering you have the 1070. If it's for Physics that's a real waste.
 

EarthDog

Gulper Nozzle Co-Owner
Joined
Dec 15, 2008
Location
Buckeyes!
the cards and the cpu start to throttle and gpuz and hwmonitor shows definite "rippling." now that i have a term for it.
gpuz and hwmonitor do not show ripple.


ive already tried using it for the leds and i still get pwr throttles
leds take up so little wattage in the first place...of course unrelated parts would still throttle. The power throttling I think you are describing has nothing to do with the psu. A 1070 and cards of that generation have power limits built in. When it goes past whatever it is set at, it will lower clockspeed. This is normal behavior.

does anyone have a hard "do not do this becasue it could ____ your ____!!!111" reason not to do this?
I do.... because you are doing this for the wrong reasons. First, you dont know what ripple is, second you think it will give you 'more power' for your throttling video cards...it wont. Video cards aren't like subwoofers where a bass hit needs extra power on store. It absolutely will not resolve what you are calling (but seemingly isnt) a problem. So to do it to be cool.... I suppose.... but it wont help your 'issue'
1) says you
2 youre thinking like, tiny small black caps. i mean something like this:
to my normie friends theyd be all like WHAT THE FUDGE only they wouldnt have said fudge granted mines not that flashy and big, but itds beep when filled and light up during heavy use.
Yep, that's my opinion. :)
Yes, I was thinking something that was actually functional (debateable) that surpreses ripple, and not a car cap that isnt going to help you in the first place. :)


Get a new PSU. A quality 750W model is PLENTY for the system you listed. :)
 
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don256us

Uber Folding Senior
Joined
Jul 17, 2003
I'm going to echo the others. This is a bad idea. It sounds like you have a problem and instead of putting emphasis on a solid correction, you are looking for something flashy. Whether you are willing to do the work or not seems like a real cluster fudge only there's no fudge. (Yes I read your posts. :) )

Before we get too deep into whether you should or should not put in a cap, lets get more information on the problem that you have.

1) Get us the specs for your machine.
2) Tell us about the problem(s) you have. (We'll limit this to computer problems. :rofl: )
3) Lets talk about solutions to the problem(s).
4) Talk about something flashy.

Lets not start with flashy, we don't know what we'll end up with.
 

wagex

Chapstick Eating Premium Member
Joined
Jan 14, 2011
capacitors only help with subwoofer amplifiers in the instance the amp is surges of draw, like a sick drum beat not a constant load, keeps a little extra juice right there handy, at constant load a capacitor will help nothing as if its constantly over the power sources capability it will just stay depleted.

p.s. dont use capacitors in car audio, they are bandaids, upgrade your wiring, upgrade your alternator, upgrade your power storage. anything to keep more power available at all times not just for short bursts.
 
OP
N

NErdgOd56

New Member
Joined
Nov 5, 2018
If the AC is unstable a decent UPS should help with that. Next is your PSU if it's unstable that's a problem for the whole system. A 7-850 W "quality" PSU shouldn't even break a sweat running all that you have connected, I do wonder why the gt730, that's just a waste of power considering you have the 1070. If it's for Physics that's a real waste.

i use the gt730 for linux and passthrough the 1070 to a windows vm. i need both, its not for physX. one is for post/linux the other is for gaming. they both get put to use a lot the gt730 more for transcoding than gaming but i do run some linux versions of games for a "split screen" experience w/friends occasionally

gpuz and hwmonitor do not show ripple.
after some googling of the term ripple, youre right its not ripple, however the 12v value drops to around 11.7 sometimes 11.3 and then back up during stress tests. also in gpuz the pwrcap reason: pwr comes up and goes away, which is what i thought you meant by ripple

leds take up so little wattage in the first place...of course unrelated parts would still throttle. The power throttling I think you are describing has nothing to do with the psu. A 1070 and cards of that generation have power limits built in. When it goes past whatever it is set at, it will lower clockspeed. This is normal behavior.
youd be correct if i hadt soldered over the 3 resistors that are used to measure how much power the card is pulling

I do.... because you are doing this for the wrong reasons. First, you dont know what ripple is, second you think it will give you 'more power' for your throttling video cards...it wont. Video cards aren't like subwoofers where a bass hit needs extra power on store. It absolutely will not resolve what you are calling (but seemingly isnt) a problem. So to do it to be cool.... I suppose.... but it wont help your 'issue'

calm down bud, i realize theyre not like subs and i now realize i didnt know what ripple was, and if i had any ripple problems it would be solved by the ups i bought, right?
regardless i get that its not ripple, thank you, (but also why did you bring that up if its not ripple?)

also it seems like no one has given me any logical reason why it wouldnt solve my issue because i am seeing usage spikes in hwmonitor, mint's system monitor and gpuz that seem to correlate with the pwr throttling and 12v rail drops. granted i havent made any graphs or anything but the problem is 12v rail drops and in cars they solve that with caps, same with the leds people put caps on them to make them not flicker from voltage drops, im experiencing voltage drops so im thinking a cap would help
Yep, that's my opinion. :)
Yes, I was thinking something that was actually functional (debateable) that surpreses ripple, and not a car cap that isnt going to help you in the first place. :)
Bah, Humbug! i bet youre fun at parties...
Get a new PSU. A quality 750W model is PLENTY for the system you listed. :)
but i dont wanna

I'm going to echo the others. This is a bad idea. It sounds like you have a problem and instead of putting emphasis on a solid correction, you are looking for something flashy. Whether you are willing to do the work or not seems like a real cluster fudge only there's no fudge. (Yes I read your posts. :) )

Before we get too deep into whether you should or should not put in a cap, lets get more information on the problem that you have.

1) Get us the specs for your machine.
2) Tell us about the problem(s) you have. (We'll limit this to computer problems. :rofl: )
3) Lets talk about solutions to the problem(s).
4) Talk about something flashy.

Lets not start with flashy, we don't know what we'll end up with.

We've already got 1, 2, and 3 covered. :)

Perhaps but there are still a lot of generalities yet.

i agree that there is a lot of generalities. i havent even mentioned the dremel or the 2 channel project amplifier im gonna add for a boot chime and voice control. stay tuned for full specs, model numbers screenshots and pics, been busy.
keep in mind that i REALLY want to put this capacitor in my computer lmao just for the shi!7s and giggles mostly. so if anyone has a legit FACTUAL reason why this is a bad idea and not just an opinion id really want to hear it. if this wont, in theory, break anything; then im gonna do it even if i get a bigger psu
 
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EarthDog

Gulper Nozzle Co-Owner
Joined
Dec 15, 2008
Location
Buckeyes!
after some googling of the term ripple, youre right its not ripple, however the 12v value drops to around 11.7 sometimes 11.3 and then back up during stress tests. also in gpuz the pwrcap reason: pwr comes up and goes away, which is what i thought you meant by ripple
Where are you reading this value? Software? If so, put a multi-meter on it and confirm. Software readings are notorious for being off. That said, the specification for the 12V rail is 5%, so 11.4V on the low side and 12.6V on the high side are considered 'in spec'.

youd be correct if i hadt soldered over the 3 resistors that are used to measure how much power the card is pulling
???? So you circumvented the power limits? Are you sure that is actually working? What process did you follow? I would like to see what was done to prevent power limit throttling. :)

That said, temperatures on those cards also lower the clockspeeds... something else to consider. ;)

calm down bud, i realize theyre not like subs and i now realize i didnt know what ripple was, and if i had any ripple problems it would be solved by the ups i bought, right?
regardless i get that its not ripple, thank you, (but also why did you bring that up if its not ripple?)

also it seems like no one has given me any logical reason why it wouldnt solve my issue because i am seeing usage spikes in hwmonitor, mint's system monitor and gpuz that seem to correlate with the pwr throttling and 12v rail drops. granted i havent made any graphs or anything but the problem is 12v rail drops and in cars they solve that with caps, same with the leds people put caps on them to make them not flicker from voltage drops, im experiencing voltage drops so im thinking a cap would help
Nobody is fired up here. Ripple can be mitigated with a UPS, sure.

I brought up ripple in the first place to define what it was, or more specifically, what an inline capacitor (what I thought we were talking about before you posted about a massive car cap) does on a PSU. See my first post here, #2.

I thought I gave you a logical reason...now that you gave more information, we have a different direction to go..............

1. You need to confirm where you are getting these voltage readings from. If software, confirm via hardware.
2. Confirm it isn't temperatures on the GPU causing throttling/drop in boost bins.

If you performed the power limit mod, but still seeing Pwr as a throttling reason in GPUz, then I am not sure that mod worked.... that or you need something else (a different BIOS for the card perhaps). Though lets be clear, the PWR throttling reason in GPUz has nothing to do with the amount of power, or lack thereof, being delivered to the GPU. It is simply telling you it is throttilng because it hit the power limit of the GPU...... hence why I am asking are you sure it was done right?

Bah, Humbug! i bet youre fun at parties...
I'm a realist and can only go by the information you give us. Its almost as fun as listening to crazy dude at the party with all their ideas but doesn't seem to be getting the whole story at once.... touche as they say! hehe!

but i dont wanna
...and that's fine. We are here to help!

That said, if your PSU (what brand and model please?) is sagging that much, though it may be 'cool' to put a car cap in there, that may be a bandaid of a bigger problem with the PSU. If it is a high quality PSU, chances are if/when it blows it won't take out other components, if its is mediocre or garbage platform, then you are risking other parts with this 'mod'.

So, to recap................(seewutididthur)

1. Confirm voltage readings I am guessing you are seeing in software with a MM.
2. For giggles, report the temps on the card (apologies if I missed it earlier)>
3. What PSU brand and model?


Please edit to add to posts. I merged the the triple post. :)
 
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mr.generic.user

New Member
Joined
Dec 1, 2018
In-line ripple caps are found in some, if not many, quality power supply cables. I have a Seasonic Focus Platinum, and a Seasonic Prime Gold, and both have ripple caps in the cpu eps and pcie cables.

If you choose to use a ripple cap, for a 12v source it should be a 25v 470uf to 25v 1000uf. My Seasonics use 470uf. You should always size a cap to be rated for twice the voltage needed. The purpose they serve is that if a device spikes current draw suddenly the cap will keep the voltage from drooping while the psu catches up. The cap will also take the brunt of the punch if a load suddenly stops drawing as much current. However, a capacitor will only have the voltage that it is charged with, so if your psu is only feeding 11.4v, then the capacitor will only be charged to 11.4v.

If your hard drives are spindle disks and are only reading or writing in bursts, then it might be a good idea to put a ripple cap in line with them, as the motors are powered by the 12v line and could could cause voltage droop if they are getting intermittently slammed.

As others have said though, you need to make sure that you are addressing the correct problem. I would start by using a good psu tester or multimeter to see if your supply voltages are good, then make sure your psu is not undersized or of poor quality. You could also use a kill-a-watt to check your wattage under max load and make sure it is never more than 80% of your power supply's rating. It works very much like a house, tall ceilings are good, but short ones and your head hits the fan.