What wattage DC-DC PSU would suffice for this mini-ITX build??

[CAT-THE-FIFTH]

In the planning stages of starting a new mini-ITX build!

Will be using a Zotac 9300 and an E4300 with an SSD. I might look at a Celery E3300 too.

Would 90W be enough??

A non-standard case will be used,well actually its not even meant for computers!!

[Pob255]

90w should be ok, I think, cannot really say as I've not messed around with pico psu's, nor did a do a power draw test on my miniITX build
Might be better to err on the side of caution and go for a 120w

[CAT-THE-FIFTH]

Thanks,for that Pob. Was originally going to rebuild my other Shuttle but found a more interesting alternative!!

[Bagnaj97]

Thanks,for that Pob. Was originally going to rebuild my other Shuttle but found a more interesting alternative!!

Build log needed methinks. I've seen what you're planning to use as a case and I reckon it's going to be a tight fit!

[scaryjim]

CAT, are you looking at the FSP 90W PSU bundle from linitx (or other places)? If so be aware that it only pushes 60W on the 12v line, and won't power a Sempron 140 + 785G mobo (I know as I had one ). If I was you'd I'd invest a little more in one of the 150W/160W PicoPSUs to make sure you have the current headroom on the 12v line - particularly with the GeForce 9300 which is quite a powerful IGP.

[CAT-THE-FIFTH]

I was looking at the 90W jobbie on LinITX and the picoPSUs on Ebay and the 120W versions too.

I just checked the price of the 150W pico-PSU on the LinITX with the appropriate AC adaptor -£90!

I do have this is an old Hiper media chassis:

http://images.bit-tech.net/content_i...chassis/13.jpg



Its 200W.

Edit!!

SPCR,measured the power consumption of the motherboard with an E7200:

http://www.silentpcreview.com/article943-page5.html

The system draws at least 65W - so that would mean at least a 120W to 150W DC-DC PSU!

[CAT-THE-FIFTH]

Had a look at the 120W DC-DC PSUs and they are a rip-off price IMHO in the UK. £50+ for a 120W set is just silly money.

I am going to see if I can use an SFF PSU instead and use it externally.

[scaryjim]

If you've got room for a 1u flex-atx PSU I can strongly recommend the FSP ones like I've got in my Aria now. They're very slim so you might squeeze it in.

What are you planning to use for the case?!?! Must be something unusual if it's causing this much consternation about a suitable PSU...!

[CAT-THE-FIFTH]

That Hiper PSU I have in the old media centre case will just about fit,but the cables cause problems. I do have a Shuttle 250W PSU which I can adapt externally.

Here are some pictures of what I am using as the case. It is an old box I found while having look around. It is made of aluminium.

[yefi]

SPCR,measured the power consumption of the motherboard with an E7200:

http://www.silentpcreview.com/article943-page5.html

The system draws at least 65W - so that would mean at least a 120W to 150W DC-DC PSU!

Unless I'm mistaken, those figures are for AC power though. ~50W will more likely be the DC draw. Seeing as they're using an E7200, not sure why you'd need 120-150W.

[CAT-THE-FIFTH]

Unless I'm mistaken, those figures are for AC power though. ~50W will more likely be the DC draw. Seeing as they're using an E7200, not sure why you'd need 120-150W.

It might doable on a smaller PSU I suppose,but I would have to be careful with the DC-DC PSU I would buy and the AC adaptor too.

But still even a 90W jobbie,is not cheap!!

[scaryjim]

And as I've already said, the 90W FSP from linitx will not power a Sempron 140 rig that only drew 60W peak from the mains on a standard AC PSU. It only provides 60W max on the 12v rail and I suspect the overcurrent protection is a little ... eager. So even a slight variation, or a few milliseconds of higher draw, will trip it. It'd be a pain to get a 90W PSU then find that one particular task you do pushes the system that bit harder and trips the OCP. I suspect that deliberate hard-loading of the CPU and GPU together could easily push the whole system up towards 100W, and you need your PSU to cope with the absolute peak draw the system could ever pull, not just the draw it will typically pull. As always, some headroom is a good thing ...

Interesting box CAT - what motorola device has given its life for your new rig? That space at the front looks like it'd fit a 1u PSU OK, but presumably you already have plans for that?

[yefi]

And as I've already said, the 90W FSP from linitx will not power a Sempron 140 rig that only drew 60W peak from the mains on a standard AC PSU. It only provides 60W max on the 12v rail and I suspect the overcurrent protection is a little ... eager. So even a slight variation, or a few milliseconds of higher draw, will trip it.

The 90W PicoPSU can handle a constant 5A on the 12V (60W), with a peak of 7A (84W). The 120W PicoPSU can handle a constant 7A (84W) with a peak of 10A (120W). If a system with a faster processor needs only ~50W, you definitely don't need more than the 120W PicoPSU.

[watercooled]

As above, check DC power rather than AC power when tested with an ATX power supply, and remember ITX boards often draw less power than ATX boards. I did some testing with a Celeron G540 in an ITX board and the most I could get it to pull was with OCCT PSU stress test, peaking at 54w at the wall when using an FSP 90w 'PicoPSU'. Under CPU load it didn't pass 45w in OCCT, again that's the highest I could get it, it was more like 37w in other apps. The 65w TDP is very conservative.

Of course, LGA1155 is a very efficient platform, and the same can't necessarily be said for 775, but there's a chance it's not as heavy on 12v as the Sempron system. However, I have managed to trip the FSP PSU by connecting another 2.5" HDD for example - the startup surge is enough to trip the OCP i.e. it seems to react very quickly, but then it doesn't have big caps like ATX PSUs so it could even be UVP reacting as the caps are discharged.

But I digress, I have one of the 90w FSP PSUs (advertised in FS, unless it's been removed as I've not bumped it in a while) if you want to try one. As mentioned in the FS thread it produces annoying coil whine mainly at low loads. See if you can find out how much DC power the system needs, and let me know if you're interested. I'd happily take it back if it's no good for you.

Oh and something else worth mentioning, unlike the 'official' PicoPSUs, the FSP one uses a 19v input and does DC-DC for 12v on the internal part, so it gets fairly hot even powering an Atom system, so would probably need active cooling for 775.

[scaryjim]

The 90W PicoPSU can handle a constant 5A on the 12V (60W), with a peak of 7A (84W). The 120W PicoPSU can handle a constant 7A (84W) with a peak of 10A (120W). If a system with a faster processor needs only ~50W, you definitely don't need more than the 120W PicoPSU.

Sorry, I thought my personal experience of that PSU not powering an ASUS 785G mobo and Sempron 140 might have some bearing on CAT's decision

As I've said, I monitored that rig closely with an AC monitor and it never rose above 60W from the wall, however the 90W FSP tripped out immediately on boot when the 4pin 12v connector was plugged in. It ran the board (although obviously it didn't boot) with the 12v connector unplugged, so it was obviously tripping on the 12v line. Which suggests that there was a milliseconds surge on power-up that was throwing the OCP, which the AC meter couldn't detect. As we have no way of knowing exactly how high that spike is, I'd rather play it safe and go for plenty of headroom than risk getting a PSU that will trip. AFAIK the efficiency curve on a DC-DC board + power brick drops off less steeply at low power draw than on a conventional PSU, and since the draw will be well above 20% anyway you'll be into the better part of the curve most of the time. Perhaps a 120W Pico will handle it, but given the small difference in price, and the greater headroom for future upgrades, I see no reason not to get the 150W version...

[watercooled]

Yeah the FSP would likely be pushing it a bit, but a standard 90w PicoPSU would probably be fine - 12v just passes through the DC-DC board so you're only really limited by the AC-DC brick.

IIRC I was able to power up my 5050e system with the FSP PSU, and I recently tried with my Llano system and it worked fine. I'll still have the 5050e platform for testing so I'll double check; it could be that yours was an earlier batch or something. I don't have access to a 775 platform but as I said I'd be happy to take it back if there are any problems.