[url=http://www.kitguru.net/components/power-supplies/zardon/silverstone-strider-gold-1200w-psu-review-sst-st1200-g/2/]http://www.kitguru.net/components/power-supplies/zardon/silverstone-strider-gold-1200w-psu-review-sst-st1200-g/2/[/url]
[img]http://www.kitguru.net/wp-content/uploads/2011/06/cables.png[/img]

[quote name=“ghostlander” post=“47275” timestamp=“1387875839”]
[quote]6) capacitors on +12vground, closer to load - better, HF fast capacitors, tantalum(?), solid(?), rating(?)[/quote]

As for solid electrolytes, you want some radial ones probably. Nippon Chemi-Con PSC 270uF/16V (diameter 8mm) are a good choice. PSA or PS are older models with a little bit higher ESR. If you can get and fit Nippon PSC 470uF/16V (diameter 10mm), that’s even better. Sanyo solid electrolytes are more expensive usually unless you’re salvaging them from broken equipment.
[/quote]

Thanks, I have a batch of Sanyo OS-CON, will use them.

Anyone has any objections to the following -

Ideal riser should be

0*) PCIEx16 -> PCIEx1, cause mining does not require bandwidth and x1 link theoretically puts lower strain on the mg chipset/CPU.
Tho some motherboards will require presence shorting if x1 risers are used in x16 slots.

1. “cut” - to prevent current flow from/to motherboard voltage regulatorsPSU and to enable use of multiple PSUs

2. have thick enough wires on +12v lines, so they won’t burn, but not thick enough to cause significant voltage drop

3. all +12v lines shorted on the riser - to not overcurrent one pin only

4. wires soldered directly to slot

5*) +5v/+3v lines also going to PSU --> “ideally”

6. capacitors on +12vground, closer to load - better, HF fast capacitors, tantalum(?), solid(?), rating(?)

7. ground line also soldered and connected to PSU

Ideal multi-PSU

1. different PSUs +12v rails separated from each other
2. different PSUs +5/+3 rails separated from each other
   3*) same PSU rails not mixing with each other
3. Properly synced - aka turning on/off at the same time

* does not really matter or not in the scope of the subject

[quote name=“ghostlander” post=“17356” timestamp=“1372081622”]
2. Attached +12V but no earth. Bad. Additional capacitor or even two can be also useful.
[/quote]

so… riser should also have thick-enough earth wire connected to PSU earth?

[quote author=ghostlander link=action=profile;u=448 date=1386650016]
[quote author=lbr link=action=profile;u=24747 date=1386624022]
Hello,

For some reason I can’t post in the thread(prly cause I’m just registered).

[url=http://forum.feathercoin.com/index.php/topic,2193.msg17391.html#msg17391]http://forum.feathercoin.com/index.php/topic,2193.msg17391.html#msg17391[/url]

[quote]Ohm’s law disagrees with you. Path from power connectors on mainboard to other PCIe slots has much lower impedance.
[/quote]
Plz define “much lower”?
I mean… ok, voltage drop will occur, so what if it’s not too high? Right?
And for multiple PSU usage… cutting is absolutely must, right?

[quote]It isn’t clean enough. Bulk capacitors inside PSU are capable of basic low frequency filtering only. Additional capacitors at loads are required. PCIe ribbon extenders (these are not risers) add considerable amounts of impedance to power rails. That includes earth. Good quality capacitors don’t bulge.
[/quote]

F.e. CoolerMaster-SIlentProM 1000W PSU, second line caps are 16v 1600uf, low esr ones.
Imo they are good enough for not only low frequency filtering…
or… there should be some low capacitance film caps as well?

If caps should be added on riser, which ones?
I assume some solid 16v?

Also, why exactly caps at loads are required?

Thanks
[/quote]

Make one post in the forum for newbies first. Much lowe is significantly lower. It depends, but the difference may be high. Multiple PSUs are fine as long as you synchronise them properly. 1600uF/16V are not good for HF as they’re liquid electrolytes. Solid or polymer tantalum are good. Watch the polarity as tantalums explode if reversed.

[/quote]

Thanks for your reply.
Sorry for asking so much questions, but you are the first person I’ve seen on digital currencies forums who actually has some technical understanding of electricity ; )

Ok, how do I measure impedance?
I can use digital testers, analog oscilloscope.
Impedance is resistance under voltage applied, right?
What do you mean by “synchronise them properly” on/off sync?

I always cut my risers in fear that +12v PSUs lines will “meet”… and nothing good happens ; )
Was my assumption right?

Hm, what if I took two oscilloscope readings - from PSU +12v line and from motherboard +12v line, would it help to determine which caps exactly are needed to be soldered on the riser?

forum forces me to make a post…
ok.