Pico PSU Connectors

PSUs: The source of DC power for all components in the PC & often a big noise source.

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readk
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Pico PSU Connectors

Post by readk » Sat Jan 09, 2010 4:02 pm

Hey Everyone,

I'm trying to use a Pico PSU with a new mainboard and video card. The mainboard needs an 8 pin 12v connector and the video card needs a 6 pin power connector. Neither are available by the Pico!

What has everyone else done in this situation? I'm not much for cutting and splicing wires. Can I order some pre-made cables? Any suggestions? Please help!

Vicotnik
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Post by Vicotnik » Sat Jan 09, 2010 4:53 pm

Even though the mainboard connector is 8pin the 4pin from the Pico will work, just leave the remaining for pins unconnected.

You need a few adapters. Molex -> 4p 12v if your kind of PicoPSU lacks the 4pin 12v connector and a Molex -> 6p PCIe. And perhaps a few Y-splitters. These are all available at most computer stores.
Last edited by Vicotnik on Sat Jan 09, 2010 4:54 pm, edited 1 time in total.

readk
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Post by readk » Sat Jan 09, 2010 4:54 pm

Thanks! I found some online but I will try to get some locally.

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Re: Pico PSU Connectors

Post by ilovejedd » Sat Jan 09, 2010 4:54 pm

readk wrote:I'm trying to use a Pico PSU with a new mainboard and video card. The mainboard needs an 8 pin 12v connector and the video card needs a 6 pin power connector. Neither are available by the Pico!
Out of curiosity, what hardware do you have?
Last edited by ilovejedd on Sat Jan 09, 2010 5:56 pm, edited 1 time in total.

readk
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Post by readk » Sat Jan 09, 2010 4:56 pm

Fanless 5750 video card and a gigabyte motherboard with AMD 605e 45w processor, also some 1.35v "eco" DDR3 memory and an Intel SSD.

Hopefully I get enough power from the 150w pico.

Parappaman
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Post by Parappaman » Sun Jan 10, 2010 12:40 am

I think you're pushing the limits there... :?
What kind of external brick will run this pico?

readk
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Post by readk » Sun Jan 10, 2010 11:13 am

Its the 12V / 12.5A brick that many places sell with the 150w Pico.

I figure 80w for the video card, 45 for the processor, that leaves 25w for everything else under max load.

Do you think I could undervolt / underclock to get some headroom?

I guess worst case I could try to upgrade to a 200w dc/dc supply or I could replace the video card.

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Post by Parappaman » Sun Jan 10, 2010 12:36 pm

Undervolting might be useful indeed :)
25w to power motherboard, memories, hard drive and whatever peripheral you connect to the computer is not really much. What worries me more is the motherboard, as usually the ones that have an 8-pin EPS connector for the CPU onboard are the enthusiast-oriented, full-ATX boards, which typically draw more power.

readk
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Post by readk » Sun Jan 10, 2010 1:35 pm

It's an enthusiast board but I got an enthusiast board so that I would have way more options for undervolt / underclock etc. I read that it's only a few watts difference between a 790 based chipset and a budget 770 chipset.

The memory I got is ECO memory and the SSD should be low power use? I only have keyboard and mouse on USB and no optical drives or hard drives. Might not even need any fans depending on how hot it gets undervolted.

5% improvement from undervolting would only be about 7 watts though. Is 10% improvement really realistic?

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Re: Pico PSU Connectors

Post by reddyuday » Sun Jan 10, 2010 4:02 pm

readk wrote: I'm trying to use a Pico PSU with a new mainboard and video card. The mainboard needs an 8 pin 12v connector and the video card needs a 6 pin power connector. Neither are available by the Pico!
You might be in a bit of a trouble here. Each circuit of a connector is good for about 6amps of current. So, a 6-pin connector can supply up to 18amps of current, i.e., 216W! Now, I don't think any graphics card out there guzzles that much power, but something like 75W is not uncommon. You probably want to check the power rating of your graphics card.

Ryboto came up with the idea of feeding 12V power directly from the external power brick instead of passing it through the PicoPSU. If you get a Dell DA-2 power brick (still available used on eBay the last time I checked), you get three circuits of power which you can feed into (i) PicoPSU, (ii) CPU and (iii) the graphics card, separately. If that is not enough, you can also get two external power bricks.
What has everyone else done in this situation? I'm not much for cutting and splicing wires. Can I order some pre-made cables? Any suggestions? Please help!
You can find my solution in this thread.

readk
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Post by readk » Sun Jan 10, 2010 6:57 pm

If the computer is off isn't feeding power into the video card dangerous??

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Post by bonestonne » Sun Jan 10, 2010 7:48 pm

ha, no.

but as everyone has pointed out, 150W for a quad and those graphics wont last long.

but the PICO also can't give you more power just because the brick has more power.

CPU and graphics aren't the only sources that require power, and that's why 150W just is barely enough.

readk
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Post by readk » Sun Jan 10, 2010 7:51 pm

I borrowed a Kill-a-watt and will try to measure at the plug.

Also I ordered a DA-2 brick on Ebay. If the 150w isn't enough, does anyone know if I would have success mating the DA-2 to the M4 power supply from short-circuit and mini-box?

I have read that the PW-200's don't work but the M4 seems to be a similar beast rated up to 250watts and there is also a handy ATX case for it.

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Post by Parappaman » Mon Jan 11, 2010 12:16 am

By going higher than 150w you're pretty much getting off the limits of what PicoPSUs can do. You might want to seriously downgrade your video card. Also, do note that a 150w brick won't be powerful enough to supply 150w of power to the computer, as the pico has its own inefficiences to count. I think you're really better off getting a full-size power supply.

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Post by reddyuday » Mon Jan 11, 2010 12:44 am

Parappaman wrote:By going higher than 150w you're pretty much getting off the limits of what PicoPSUs can do. You might want to seriously downgrade your video card. Also, do note that a 150w brick won't be powerful enough to supply 150w of power to the computer, as the pico has its own inefficiences to count. I think you're really better off getting a full-size power supply.
If the video card is powered directly from the power brick, then the PicoPSU's limitations are not relevant.

But this system does stretch the limits of DA-2 + PicoPSU arrangement. It will be interesting to see if it works! I encourage the OP to try it. There is always the option of going to two DA-2 if it doesn't work.

Uday

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Post by Parappaman » Mon Jan 11, 2010 1:33 am

reddyuday wrote: If the video card is powered directly from the power brick, then the PicoPSU's limitations are not relevant.
It might be relevant as the PCI-E slot supplies up to 75w to the video card, and the 6 pin connector the rest of it. For this 80w video card, that would translate in a big question mark on what takes its power from...

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Post by reddyuday » Mon Jan 11, 2010 4:20 am

Parappaman wrote: It might be relevant as the PCI-E slot supplies up to 75w to the video card, and the 6 pin connector the rest of it. For this 80w video card, that would translate in a big question mark on what takes its power from...
I am confused. I thought the 6-pin connector was the PCI-E connector. See here. Are there two 6-pin connectors to this video card?

Perhaps you mean that it takes 75W from the motherboard? I think that is unlikely. But we should really see the power specification of this video card. Is one available?

Uday

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Post by Parappaman » Mon Jan 11, 2010 4:27 am

reddyuday wrote:
Parappaman wrote: It might be relevant as the PCI-E slot supplies up to 75w to the video card, and the 6 pin connector the rest of it. For this 80w video card, that would translate in a big question mark on what takes its power from...
I am confused. I thought the 6-pin connector was the PCI-E connector. See here. Are there two 6-pin connectors to this video card?

Perhaps you mean that it takes 75W from the motherboard? I think that is unlikely. But we should really see the power specification of this video card. Is one available?

Uday
The PCI-E slot I mentioned is the slot on the motherboard, and the 6-pin connector is the PCI-E connector. Don't panic! :lol:

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Re: Pico PSU Connectors

Post by ryboto » Mon Jan 11, 2010 6:33 am

reddyuday wrote:
readk wrote: Ryboto came up with the idea of feeding 12V power directly from the external power brick instead of passing it through the PicoPSU. If you get a Dell DA-2 power brick (still available used on eBay the last time I checked), you get three circuits of power which you can feed into (i) PicoPSU, (ii) CPU and (iii) the graphics card, separately. If that is not enough, you can also get two external power bricks.
What has everyone else done in this situation? I'm not much for cutting and splicing wires. Can I order some pre-made cables? Any suggestions? Please help!
You can find my solution in this thread.
Just so it's clear, with this method I was able to drive a 3.0ghz Q9400, single hard drive, and an HD3870. Recently I've upgraded to a 5770, Power levels haven't really changed. I just really wouldn't trust the single input line to the Pico to carry all that current reliably for a long period of time. Ever since I fixed my poor soldering job, I've yet to have a single issue with the system.

readk
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Re: Pico PSU Connectors

Post by readk » Mon Jan 11, 2010 8:32 pm

That seems like a lot more power considering you're driving a hard drive and a higher wattage processor! I'm going to try the kill-a-watt tomorrow and will report back.

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Post by tehcrazybob » Mon Jan 11, 2010 10:18 pm

Parappaman wrote:It might be relevant as the PCI-E slot supplies up to 75w to the video card, and the 6 pin connector the rest of it. For this 80w video card, that would translate in a big question mark on what takes its power from...
I don't actually know, but I doubt that very much. The PCIe slot is rated to provide up to 75 watts to a card if there's no aux power connected, but as soon as you hook up the 6-pin PCIe power, I doubt the motherboard supplies any meaningful level of power at all through the slot. In fact, I wouldn't be surprised if high-powered cards with the 6-pin connector don't even have any traces connected to the power pins in the slot. That would explain why some faster cards fail to boot without the aux power connected, even though they're not pulling anything like 75 watts in 2D mode.

I've got a friend with a clamp-on ammeter. Next time I'm over there, I'll stick the meter on his PCIe 6-pin lead and see how much power is running through it at idle. His X1950 should idle around 25 watts - if you're right, there will be no power running through the aux; if I'm right, there should be about 25 watts.

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Post by Parappaman » Tue Jan 12, 2010 12:39 am

tehcrazybob wrote:
Parappaman wrote:It might be relevant as the PCI-E slot supplies up to 75w to the video card, and the 6 pin connector the rest of it. For this 80w video card, that would translate in a big question mark on what takes its power from...
I don't actually know, but I doubt that very much. The PCIe slot is rated to provide up to 75 watts to a card if there's no aux power connected, but as soon as you hook up the 6-pin PCIe power, I doubt the motherboard supplies any meaningful level of power at all through the slot. In fact, I wouldn't be surprised if high-powered cards with the 6-pin connector don't even have any traces connected to the power pins in the slot. That would explain why some faster cards fail to boot without the aux power connected, even though they're not pulling anything like 75 watts in 2D mode.

I've got a friend with a clamp-on ammeter. Next time I'm over there, I'll stick the meter on his PCIe 6-pin lead and see how much power is running through it at idle. His X1950 should idle around 25 watts - if you're right, there will be no power running through the aux; if I'm right, there should be about 25 watts.
It's not about "who is right", it's about a card that is known to draw 80w at load and no one ever measured how much of it actually comes from the 6 pin connector... :?
The X1950 you have on hand could as well be the only card in the known world to behave in the way you will measure it, so you're not going to find an absolute law :mrgreen:

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Post by ryboto » Tue Jan 12, 2010 5:24 am

Parappaman wrote: It's not about "who is right", it's about a card that is known to draw 80w at load and no one ever measured how much of it actually comes from the 6 pin connector... :?
The X1950 you have on hand could as well be the only card in the known world to behave in the way you will measure it, so you're not going to find an absolute law :mrgreen:
I think x-bit labs makes a measurement of what comes from the slot vs the 6-pin when they do GPU power consumption tests.

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