SPCR

Had a couple comments in another forum about my system being too ambitious for a 150w brick / PicoPSU 150. I'm putting it together tomorrow since all the parts are here; should I bother?

AMD 605e
Gigabyte GA-790XTA-UD4
2x 2gb 1.35w eco DDR3
Fanless Powercolor 5750 video
Intel 80gb SSD

Do you think I could underclock or undervolt to maybe shave 10% off of my power use if it's a close call? I want to run this all on 1 fan because it's in a very noise sensitive environment.

I am guessing that this system will use more than 150W at full gaming load. Your biggest trouble areas will probably be the 12V connectors turning to "crispy critters" before the year is out. As the connections deteriorate from silver to tan to black the system will become increasingly unreliable. Unreliable hardware is the worst nightmare.

I'd put it all together using a standard power supply with ample capacity, max out the load on all components, and measure the total power draw at the socket.

If it is very close to or exceeds 150W, you may have issues. If not, you should be OK. I'm not sure how the efficiency of a 150W power brick + PicoPSU compares with a standard ATX PSU, but you may want to build in a factor for this too.

With that hardware set I would guess that your most effective power reduction possibility would be to under clock and/or under volt the video card.

Why do the connectors get crispy-fied?

Also what do you recommend to measure the power draw? I don't have any hardware for this. Can I get some kind of device inexpensively?

What do you guys think about upgrading to this?

http://www.mcubed-store.com/catalog/pro ... cts_id=179

I'm kind of in a panic now since I bought all these parts and want to get going on the build! But I really want to push the low power / low heat / 0db envelope with this build... Otherwise I would have gotten a faster processor etc.

I could go with a passive internal PS but I think it would create a lot of heat in the case? I was hoping that with a brick I could passively cool the CPU and Video Card and maybe just have 1 500rpm exhaust.

"about upgrading to this?"

That's BS!!!. So is the price.

if this is a gaming build, your not going to get away with that much power draw and a PICO.

It doesn't matter if it's in a "noise sensitive" area, you're entering power draw that will murder the PICO you just bought.

Go with a Corsair or Seasonic 300-400W power supply. it's really not going to give you much of an increase in noise. i promise.

read the reviews on this site, it's here as a tool.

With todays technology, a hot gaming system can't be silent while gaming. It can be reasonably quiet and non-annoying at idle. It can be very, very quiet during S3 sleep state.

PWM fans are a good way to easily achieve quiet operation at idle and still supply cooling power at full load.

Here are some budget ideas:
=> The CPU PWM fan control can be used to operate the chassis fan. The chassis fan, which is at the outside of the chassis, is often more audible than the CPU fan, which is inside the chassis.
=> The PWM fan control can operate more than one fan with a Y-adapter.
=> The Scythe Gentle Typhoon (which unfortunately isn't a PWM type) has the most non-annoying noise signature that I know of.

"a single cooling fan"

A General Statement:

With a standard ATX mini-Tower chassis, with the PS at the top, then you might be able to accomplish your noise requirements with only the PS fan if you have a sufficiently low wattage passive cooled video card and a sufficiently low wattage passive passive cooled CPU and a robust and efficient PS like an Enermax 82+ series and all the other vents at the rear of the chassis are blocked off to prevent air convection short circuits.

I don't understand why I need a 400 watt power supply for a 45 watt processor and max 80 watt video card? It would be helpful to have some of these questions answered so I know the "why" of things. What is the upper limit for the pico? Why is that hFX supply "BS"?

The main reason it has a 5750 video card is because I read that it has a very small power footprint even vs all of the 4xxx series cards. I can underclock it and murder the performance or just buy a new card, this would be a good solution vs adding a power supply with loud fan for me. The video card only needs to be as fast as the machine we're replacing which had I think a (now broken) geforce 7900 series card in it.

Price isn't really an issue, but noise is, its going to need to run in a soundproof area with audio recording etc.

This is why I was originally trying to get down to 0 fans which is why I wanted the power supply out of the case to remove heat. Its not a gaming machine which is why I can sacrifice cpu and video performance to get the noise and heat down - I don't really care if I have to buy another video card etc.

!?! OOPS ??!?

When you said GA-790XTA-UD4 and HD 5750, I assumed a gaming scenario. Your heat and power requirements problem are solved if you change to something like a ASUS M4A785-M.

So please tell us, exactly what are your requirements.

I do appreciate all the help guys!

Now I am thinking maybe I order a Dell DA-2 brick and an M4 supply and ebay the pico psu..

The machine won't be a FPS gaming machine but it will need to run DirectX 3D graphics applications and light video editing and do light 3d graphics development, so the card needs to be able to do DirectX 10 and be decent at it, plus playback HD video. I don't think onboard video will work although the 5750 is overkill for sure. I could maybe get away with something like an nvidia GT220 or 240 which I think is quite a bit slower.

The requirements are really a very-nearly passive and silent machine (even when a microphone is on in a soundproofed room) that can do light to medium multimedia work in 2D and 3D with cost basically not a huge factor.

You asked earlier what you could buy to measure power draw..not sure if you got an answer, but here's one..

http://www.newegg.com/Product/Product.a ... -_-Product

I own one..it's a great tool to add to the arsenal. Ill probably have it for my whole life. Keep in mind, this measures AC power draw..so if your PSU is rated for 150W DC, that will show up a little higher on this meter because of the inefficiencies in the PSU itself.

readk wrote:I don't understand why I need a 400 watt power supply for a 45 watt processor and max 80 watt video card?

You might not _need_ but you don't lose ANYTHING by going for 400W. The energy loss only depends on the efficiency of the PSU at the load you are throwing at it.

I'm really surprised that given the availability of the DA-2 nobody has an out of the box solution? I'm hoping to give that a try with the M4-ATX since everyone seems to have problems with the PW-200 power supplies after I test out the Pico a bit more.

I'm thinking maybe with underclocking/undervolting if I shave off 10% of my power draw I can make it work with the Pico though.

I'd hate to have to get a new video card but that's probably what I should have done, just stuck with something that doesn't have an external connector.

"I don't understand why I need a 400 watt power supply"

If you add another 30W for all the other heat sources in your chassis to the 45W + 75W then you have 150W. An efficient 400W PS will have robust enough components to handle the high intake temperatures of your minimal air flow system without ramping up the fan speed to a loudness that you don't want.

I see what you're saying. But what if it will only be 25w and I can undervolt or underclock the hardware to free up 10w more. Then its 135w under max load, and idles well under that. Would that be so bad?

I don't think I want to deal with the heat of a bigger power supply, cooling it will be too loud based on my experience, or else it will just get way too hot. I'm not going to give up so easy, I will try a few power supplies and if that doesn't go well I'll try to knock 30w off the video card by replacing it with something else. I know there is a GT240 and a GT220 out there that are passive and probably come in well under the 5750.

Do you know if the kill-a-watt is really useful? Does reading AC at the plug really give you a good picture?

the AC reading at the plug will always tell you slightly more than your DC power draw. So yes, because it is consistent, it is very useful. Say you know your PSU is 80% efficient roughly. If your Kill-a-watt is measuring 100W for example, you know that your components are eating 80W of that.

There really isn't any easier, cheaper alternative to measuring power draw in my opinion.

Any idea how efficient the brick will be though? No efficiency specs written on it. Pico advertises 95% though.

Xbit Labs measured the the 5750 at 60w under load. And the benchmarks they use (Furmark and 3DMark06) tend to be a bit more demanding than real world applications I think.

http://www.xbitlabs.com/articles/video/ ... 750_5.html

So you could probably get by with the 150w PicoPSU and power brick. It'd be closer than I'd be comfortable with, but it would probably work, especially if you were to undervolt the CPU and video card (no idea if it's even possible to undervolt the GPU, and the CPU probably couldn't be undervolted much considering it's already a 45w model). I'd keep an eye on the barrel plug the PicoPSU uses, though. Supposedly the connector isn't designed to handle more than 8A of continuous current, or about 100w. I never understood why they build the unit like this when it's supposed to be rated for 150w, but whatever. Just make sure that the connector isn't overheating under load. If it is, you'll have to replace it with a more robust one.

I'm worried about two things:

1. +12V current stability/capability: Can your power brick sustain such a high load on 12V lines continuously?
2. Power-up peak: Your power brick may not be able to tolerate peak value of instantaneous power-up. After all, you're drawing power nearing the full capacity of continuous load, let alone instantaneous peak load.

The safe bet is Nexus Value 430W or Enermax Eco80+ 350W.

readk wrote: I don't think I want to deal with the heat of a bigger power supply, cooling it will be too loud based on my experience, or else it will just get way too hot.

it's the efficiency that counts, because power that's not consumed is put off as wasted heat.

bigger supplies can be better, in the sense that they will have bigger heat sinks(more surface area to dissipate heat), and would therefore rely less on fan rpm.

look at the spcr review of the cp-850, see how quiet it is.

My experiences with AMD CPU mainboards mostly has been that any type of CPU core voltage or speed tinkering prevents Cool'n'Quiet from automatically undervolting and underclocking the CPU during idle.

Perhaps someone out there knows for sure about your Gigabyte GA-790XTA-UD4.

It seems to depend on the board. He should be able to adjust the voltage and HTT frequency on that Gigabyte board. The only thing that breaks CnQ on the Gigabyte mobo in my sig is adjusting the CPU multiplier.

And I think you can use Windows software like K10Stat to adjust the multiplier settings for CnQ.

Results are in:

viewtopic.php?t=57219

BUT

The nice people who sold me my Pico PSU have offered to let me exchange it for an M4 which I will use with my Dell DA-2 I just got today.

However, the Pico does seem to work and the Killawatt says < 150 watts.

Should I bother exchanging for some setup that may not even work better than this?