Or use an adjustable power supply, something like this one (just an example):

http://www.ebay.com/itm/30-Amp-12-Volt-DC-13-8V-Regulated-Power-Supply-for-Ham-Radio-CB-US-SELLER-/360874766820

Output voltage can be set with a potmeter, so you can easily adjust for
the IR drop in the wiring. And often these are cheaper than PC PSUs.

You will be suprised with the hashrate when the boards are operated
'slightly' over 12 Volts:) Have six of them hashing now with a total of
202.78 GH/s at 13V1.  (Remember this warranty thingie;)

intron

Exactly right:) It's an 8 slot M-board with Ethernet.

Like so:

https://i.imgur.com/XbdZjyM.jpg

You forgot the (TM) sign;)

PM-ed you.

No, double rainbows and unicorn tears.

LOL:-)

That will indeed increase stability of the H-CARDs.
Sticking packing foam peanuts between the cards
also helps a lot:)

Thank you Hal.

I consider Peltier cooling for this summer.
--
Beware to keep temperatures above dew point:)

And 'overvolted' it looks something like this:

 cgminer version 3.8.5 - Started: [2014-03-01 13:48:44]
--------------------------------------------------------------------------------
 (5s):211.5G (avg):212.1Gh/s | A:13029070  R:36550  HW:13  WU:2964.3/m
 ST: 2  SS: 0  NB: 446  LW: 2628905  GF: 0  RF: 0
 Connected to btcguild.gigaforge.com diff 128 with stratum as user xxxxxxx
 Block: 925b0f2f...  Diff:3.81G  Started: [15:18:54]  Best share: 35.6M
--------------------------------------------------------------------------------
 [P]ool management [S ]ettings [D]isplay options [Q]uit
 BXF 0:  52.7C         | 33.61G/33.63Gh/s | A:2072842 R:5434 HW: 0 WU:469.9/m
 BXF 1:  53.6C         | 32.49G/32.60Gh/s | A:1986468 R:5164 HW: 0 WU:456.1/m
 BXF 2:  60.1C         | 33.79G/33.85Gh/s | A:2091120 R:4800 HW: 1 WU:472.9/m
 BXF 3:  59.9C         | 33.99G/34.01Gh/s | A:2076144 R:4896 HW: 0 WU:475.3/m
 BXF 4:  53.0C         | 39.17G/38.80Gh/s | A:2390528 R:6400 HW: 0 WU:542.5/m
 BXF 5:  52.7C         | 39.36G/39.27Gh/s | A:2411968 R:9856 HW:12 WU:548.7/m
--------------------------------------------------------------------------------

 [2014-03-04 15:29:59] Accepted 0da5cd6b Diff 4.8K/128 BXF 1
 [2014-03-04 15:30:00] Accepted 01a9d4d4 Diff 154/128 BXF 3
 [2014-03-04 15:30:00] Accepted 01bec1a5 Diff 147/128 BXF 3
 [2014-03-04 15:30:01] Accepted 31624882 Diff 1.33K/128 BXF 4
 [2014-03-04 15:30:05] Accepted 01d05f2a Diff 141/128 BXF 4
 [2014-03-04 15:30:08] Accepted a5018370 Diff 397/128 BXF 4
 [2014-03-04 15:30:12] Accepted 0129ec3e Diff 220/128 BXF 3
 [2014-03-04 15:30:19] Accepted 01ebb26e Diff 133/128 BXF 4

A voltage of 13V35 was measured with a voltmeter at the terminals
of the power supply.

intron

In a unrolled architecture the operations that make up
a certain calculation are laid down individually in silicon
in a pipelined fashion. This means every clock cycle another
calculation can be started and (after the pipe delay) every clock
tick another result is produced.

In a rolled architecture there is only a single 'main calculation
block' and partial results are fed back into that block until a
result is produced. Results are produce less frequent, but
the silicon area taken up is also smaller, so more loops can
be implemented on the same die.

When you roll up a calculation to a tight loop taking up less
area, changes of a defect of that block are smaller. However
there is a small penalty in silicon area for defining the stop condition
(i.e. 'is the calculation ready or not?').

Will send you some more chips to play with:)

LOL:)

S-HASH can be overclocked by changing a resistor value.
Look for resistor R01T near the power module and replace
it for one with a lower value. Not sure what it is now, try
100K/82K/70K.

Only try this when you know what you do though!
You can damage the board when the output voltage
is made too high.

Read the datasheet of APTS050A0X3-SRPHZ for more info.

intron

A low-cost NTC and a small MCU running Steinhart-Hart would do the trick:)

intron

The hashrate of a strings design is heavily dependent
of the supply voltage. You are sure this didn't change?

I am definitely interested in them when they come out.  Looks great so far.
If you need someone to test any units for you let me know.
--
Thank you for the offer, but we are 'testing' the hell out
of these things already. And for more than Two Weeks (tm)

intron

Is reeds verkocht.