12-volt-only motherboard and linear power supply?

[Bullwinkle]

Lebouwsky, pushing others wasn't on my mind when I originally posted this. I was actually interested in ways of accomplishing certain things more cheaply than others had. I'm glad I posted because various replies helped me find a better path to accomplish those things.

 

I will try to follow up with an A/B comparison of the two power supply routes (switching vs linear) for the server I'm building. That seems like a small way I can return the favors, and perhaps it will interest you too.

 

Again no pushes intended.

[Lebouwsky]

On 26-4-2017 at 4:49 AM, Bullwinkle said:

Lebouwsky, pushing others wasn't on my mind when I originally posted this. I was actually interested in ways of accomplishing certain things more cheaply than others had. I'm glad I posted because various replies helped me find a better path to accomplish those things.

 

I will try to follow up with an A/B comparison of the two power supply routes (switching vs linear) for the server I'm building. That seems like a small way I can return the favors, and perhaps it will interest you too.

 

Again no pushes intended.

My post was not directed to you Bullwinkle, it was more like a ........ brain fart? 

 

About the 12v motherboard; on page 59 of the post "a novel way to" Romaz suggests a 12v Supermicro SoC board as one of the best boards to build a server from. Its nog cheap though.

[Johnseye]

On 4/25/2017 at 9:49 PM, Bullwinkle said:

Lebouwsky, pushing others wasn't on my mind when I originally posted this. I was actually interested in ways of accomplishing certain things more cheaply than others had. I'm glad I posted because various replies helped me find a better path to accomplish those things.

 

I will try to follow up with an A/B comparison of the two power supply routes (switching vs linear) for the server I'm building. That seems like a small way I can return the favors, and perhaps it will interest you too.

 

Again no pushes intended.

 

Did you end up buying the components?  I just built a 12v server using the following.  I have a Paul Hynes SR7 LPSU on order, but it will be a while before it's ready.  In the mean time I'm using the HD Plex supply.

 

Streacom case

ASUS Q170T/CSM.  Alternatively there are other boards available but I wanted one with M.2 and dual NICs.

Intel i7 7700T.  Still rated at 35w I wanted the most powerful processor to upsample.

Intel M.2 SSD 5400s.  80 mW active

8GB of Crucial DDR4

 

As I mentioned I'm temporarily using the HDPlex Internal 160W AC/DC adapter.  It's connected to the internal 12v jack on the board.  It will be replaced once I get the SR7 LPSU.  This is about as simple as it gets. There is one other simpler solution which is a Supermicro board that has the CPU built in.  Those boards run from $800 to $1k however.  We've been discussing this over in the A novel way to... thread.

[Bullwinkle]

6 minutes ago, Johnseye said:

 

Did you end up buying the components? 

 

Hi Johnseye, nice to see where you are. Yesterday morning I posted this, showing where I am but mainly to share the power consumption figures which I thought might help others.

 

https://www.computeraudiophile.com/forums/topic/31667-power-consumption-test-for-a-first-draft-server-build/

 

[Johnseye]

7 minutes ago, Bullwinkle said:

Hi Johnseye, nice to see where you are. Yesterday morning I posted this, showing where I am but mainly to share the power consumption figures which I thought might help others.

 

https://www.computeraudiophile.com/forums/topic/31667-power-consumption-test-for-a-first-draft-server-build/

 

 

What were you running when you benchmarked 74w?

 

[Bullwinkle]

9 minutes ago, Johnseye said:

 

What were you running when you benchmarked 74w?

 

A freeware benchmarking package, Sisoft Sandra Lite, employing four of its cpu and vm benchmarking tests. I described what I did further up in the post. To a certain extent I'm also making inferences based on Miska's linked post and later posts, indicating that even without offloading to CUDAs, he didn't observe the i5-7600T getting beyond about 50% utilization. Sandra pushed all four cores to 100% for a good five minutes.

[Johnseye]

Just now, Bullwinkle said:

A freeware benchmarking package, Sisoft Sandra Lite, employing four of its cpu and vm benchmarking tests. I described what I did further up in the post. To a certain extent I'm also making inferences based on Miska's linked post and later posts, indicating that even without offloading to CUDAs, he didn't observe the i5-7600T getting beyond about 50% utilization. Sandra pushed all four cores to 100% for a good five minutes.

 

No kidding, 74w with 4 cores at 100% ?  That's great.  I have no idea what my power consumption is, but if that's a max I'll be in good shape.  Thanks for the info.

[tedwoods]

Well, the jury has come to a verdict and it's in favor of the direct connection, especially with switch re-clocking...

[simonklp]

On Sunday, April 16, 2017 at 9:12 AM, Superdad said:

Most all of the current Intel NUC motherboards will run from just a 12V supply.

 

You are much better off putting the supply external to the case.  But then I am biased as I build and sell a popular choke-filtered, dual-output, 5-7 amp LPS.  

 

Also, having the DC-DC switching converters on the motherboard does not offer much advantage over choosing the ATX mobo you want and plugging in a picoPSU to drop the 12V to 5V and 3.3.  Comes complete with the harness and everything.

 

 

 

I am thinking of building a Audio PC. Could anybody be so kind to give me some advice on which of the following is a better option in terms of SQ: -

1) To use a ATX Linear Power Supply with ATX motherboard.

2) To use a 12V DC LPS with motherboard capable of accepting 12V input.

 

The dilemma here is that, while on one hand, there are some very good 12V DC LPS available in the market, there is only very limited choice for ATX LPS. Furthermore, in terms of specifications and reputation, it appears that some 12V DC LPS are much better than the ATX LPS.

 

But, on the other hand, as mentioned above by @Superdad, having the DC-DC switching converters on the motherboard may have adverse effect on SQ when compared with the ATX mobo together with a dedicated DC-ATX converter for Hi-Fi (e.g. HDPLEX).

 

Could anyone kindly give some advice on the above?

 

Thanks! 

[Johnseye]

41 minutes ago, simonklp said:

 

I am thinking of building a Audio PC. Could anybody be so kind to give me some advice on which of the following is a better option in terms of SQ: -

1) To use a ATX Linear Power Supply with ATX motherboard.

2) To use a 12V DC LPS with motherboard capable of accepting 12V input.

 

The dilemma here is that, while on one hand, there are some very good 12V DC LPS available in the market, there is only very limited choice for ATX LPS. Furthermore, in terms of specifications and reputation, it appears that some 12V DC LPS are much better than the ATX LPS.

 

But, on the other hand, as mentioned above by @Superdad, having the DC-DC switching converters on the motherboard may have adverse effect on SQ when compared with the ATX mobo together with a dedicated DC-ATX converter for Hi-Fi (e.g. HDPLEX).

 

Could anyone kindly give some advice on the above?

 

Thanks! 

 

You have the answer for reasons you mention. Don't worry about the on board DC converters, they're better than the HDPlex ATX converter which is better than the Pico converter. Get yourself the best 12v LPS you can afford and if it can handle 19v as well a lot more opens up to you. 

[Superdad]

2 hours ago, simonklp said:

 

I am thinking of building a Audio PC. Could anybody be so kind to give me some advice on which of the following is a better option in terms of SQ: -

1) To use a ATX Linear Power Supply with ATX motherboard.

2) To use a 12V DC LPS with motherboard capable of accepting 12V input.

 

The dilemma here is that, while on one hand, there are some very good 12V DC LPS available in the market, there is only very limited choice for ATX LPS. Furthermore, in terms of specifications and reputation, it appears that some 12V DC LPS are much better than the ATX LPS.

 

But, on the other hand, as mentioned above by @Superdad, having the DC-DC switching converters on the motherboard may have adverse effect on SQ when compared with the ATX mobo together with a dedicated DC-ATX converter for Hi-Fi (e.g. HDPLEX).

 

Could anyone kindly give some advice on the above?

 

Thanks! 

 

 

A couple of things to keep in mind (and I promise I am not saying this to sell more of our choke-filtered, dual-output, 5-7 amp JS-2 LPS units--we already sell all we can build);

 

a) The "ATX" linear supplies, just like standard SMPS ATX supplies are still feeding 12V (and 5V) into both the 20/24-pin power socket and the 4-pin higher-current 12V socket of the motherboard.  So the DC-DC switching converters of the motherboard are used regardless of if you power the mobo thru a back-panel facing 12V/19V DC jack or the main board connection.  

 

b) The various picoPSU-type adapters (and I see now that HDPlex has expanded into that space with adapters smaller than their big version) are all still DC-DC switching regulators.  I know that the wiring harness of the 12V picoPSU units splits out the 12V to the square 4-pin socket for main CPU supply (which still goes through a bunch of DC-DC regs as no chips actually run from 12V).  So I never really followed the point of using a 19V input adapter other than perhaps to reduce the current requirement to provide the critical 12V going to the mobo.

 

c) As for the other voltages: If one is building a system, then you ought to consider supplying 5V--to things like SATA drives and USB cards--directly from an LPS.  That is better than going through the DC-DC switching regs of the adapter boards.  The wiring for such is not difficult, and these days most modern motherboards are not fussy about power-on sequencing.

 

So it seems to me that one can either keep things simple with a 12V input NUC-type board, or with a simple 12V picoPSU  wth the harness it comes with:

[hurka]

Atx standard use separated socket for cpu,this hungry boy can feed cheaper smps. Atx mobo +hd plex ,pico or others, feed good  psu (sotm sps500,battery,u caps,.....)

[simonklp]

5 hours ago, Johnseye said:

 

You have the answer for reasons you mention. Don't worry about the on board DC converters, they're better than the HDPlex ATX converter which is better than the Pico converter. Get yourself the best 12v LPS you can afford and if it can handle 19v as well a lot more opens up to you. 

 

Thank you for your advice.

 

But, should a DC-ATX converter dedicated for Hi-Fi application be better than the on-board DC converter already built in the motherboard, shouldn't it?

 

Kindly please advise. Thanks.

[simonklp]

3 hours ago, Superdad said:

a) The "ATX" linear supplies, just like standard SMPS ATX supplies are still feeding 12V (and 5V) into both the 20/24-pin power socket and the 4-pin higher-current 12V socket of the motherboard.  So the DC-DC switching converters of the motherboard are used regardless of if you power the mobo thru a back-panel facing 12V/19V DC jack or the main board connection. 

 

Alex, thank you for your kind advice.

 

But I notice that the ATX power supply connector already includes +12V, -12V, +5V, +3.3V and ground. Is it still necessary to go through DC-DC switching converter of the motherboard? Even if it is still necessary, would it be used just for the voltage other than that already included in the ATX connector? So, does using ATX LPS still avoid the DC-DC switching converter built-in the motherboard, doesn't it?

[Summit]

With an ATX power supplies it’s not necessary to go through the DC-DC switching converters on the motherboard. An ATX power supply has separate rails for the +12V, -12V, +5V, +3.3V which means that you can attach a power cables on the ATX PSU and on the other end connect the Molex connector direct on the hard drive, PCIe card, hard drive etc. You normally have a primary and one secondary side on a good SMPS ATX PSU. The primary side is powering the mobo and its CPU and GPU while the secondary side handle the rest. The secondary side rails are DC-DC converted already in the PSU to +5V, +3.3V.

 

For gaming not only high power is of importance and it’s why ripple and transient response etc are measured in many hard core computer reviews. I have got good SQ result with a SMPS ATX PSU combined with a separate LPS for powering some audio critical components like USB card, NET card and the OS hard drive. Even without the separate LPS my ATX PSU is pretty good IMO.

 

Look at the ripple, components used and built on this ATX PSU for example:

http://www.tomshardware.com/reviews/evga-supernova-650-p2-power-supply,4364-8.html

[ismewor]

16 hours ago, simonklp said:

But I notice that the ATX power supply connector already includes +12V, -12V, +5V, +3.3V and ground. Is it still necessary to go through DC-DC switching converter of the motherboard? Even if it is still necessary, would it be used just for the voltage other than that already included in the ATX connector? So, does using ATX LPS still avoid the DC-DC switching converter built-in the motherboard, doesn't it?

@simonklp Even using the ATX 24pin input you still can't avoid the voltage regulators on the motherboard. reason being there are some voltage specific needed other than those regular one. Example like Dimm Ram 1.8v to 2.5v according to spec. CPU could use anything like 1.3v, 1.8v etc intel and amd are different. other like PCI-E use 0.8v etc. 

on the other hand, 12V only input will have to go through couple more onboard regulators to +5v, +3.3v, -12v so ATX linear can avoid some of the regulators but not all. 

 

Hope this help some.

[simonklp]

16 hours ago, Summit said:

With an ATX power supplies it’s not necessary to go through the DC-DC switching converters on the motherboard. An ATX power supply has separate rails for the +12V, -12V, +5V, +3.3V which means that you can attach a power cables on the ATX PSU and on the other end connect the Molex connector direct on the hard drive, PCIe card, hard drive etc. You normally have a primary and one secondary side on a good SMPS ATX PSU. The primary side is powering the mobo and its CPU and GPU while the secondary side handle the rest. The secondary side rails are DC-DC converted already in the PSU to +5V, +3.3V.

 

For gaming not only high power is of importance and it’s why ripple and transient response etc are measured in many hard core computer reviews. I have got good SQ result with a SMPS ATX PSU combined with a separate LPS for powering some audio critical components like USB card, NET card and the OS hard drive. Even without the separate LPS my ATX PSU is pretty good IMO.

 

Look at the ripple, components used and built on this ATX PSU for example:

http://www.tomshardware.com/reviews/evga-supernova-650-p2-power-supply,4364-8.html

 

@Summit Thank you very much for your kind advice and sharing.

[simonklp]

11 hours ago, ismewor said:

@simonklp Even using the ATX 24pin input you still can't avoid the voltage regulators on the motherboard. reason being there are some voltage specific needed other than those regular one. Example like Dimm Ram 1.8v to 2.5v according to spec. CPU could use anything like 1.3v, 1.8v etc intel and amd are different. other like PCI-E use 0.8v etc. 

on the other hand, 12V only input will have to go through couple more onboard regulators to +5v, +3.3v, -12v so ATX linear can avoid some of the regulators but not all. 

 

Hope this help some.

 

@ismewor Also thank you very much for your kind advice and valuable information.