Asrock H81 Pro BTC sees only 4/5 cards.

[Undefined31415]

Hello, I seem to be having a problem getting all 5 of my cards recognized by any OS, even with the use of dummy plugs.
When I checked it out with BAMT (which shows, upon each boot, which cards it finds), I found that it only saw one of my 77xx series cards.

To continue checking, I removed the 7790 and it saw all 4 remaining cards.  Then I reconnected the 7790 & removed the 7770, however, it also saw all 4 remaining cards.  This leads me to believe that there's some limitation by the motherboard, CPU, OS, or some factor, other than the actual cards (or their connections).

My mining setup:

Asrock H81 Pro BTC
Intel Pentium G3220
1x 2GB DDR3 RAM

3x 7850
1x 7790
1x 7770

Thermaltake 600W PSU & Thermaltake 700W PSU, load distributed as follows:

Thermaltake 600:
Motherboard & CPU
2x 7850

Thermaltake 700:
1x7850
1x7790
1x7770

Operating systems tried:
Ubuntu 12.04
Ubuntu 13.04
BAMT 1.4

All risers are powered, and powered in a way such that the riser is always powered by the same PSU as the 6 pin PCIe connector to its corresponding card.


My thought is that the problem is the Pentium CPU's limitations on "PCI Express Configurations", seen on the Intel site, under Expansion options.  Does anyone have another idea why I can't get all 5 cards running?  http://ark.intel.com/products/77773/Intel-Pentium-Processor-G3220-3M-Cache-3_00-GHz

I would appreciate any suggestions!

[grendel25]

windows 8.1 pro and never look back.

[Planethill]

windows 8.1 pro and never look back.

This.

[MinerP]

windows 8.1 pro and never look back.

This.

If this doesnt work, its probably your riser. I have experienced a 25% failure rate of all risers. Countless wasted hours just to find out it was a riser problem.

[soulnecturn]

Possible reasons and ways:

1) connect 1 card, start system, if ok turn off, connect second card, if ok turn off, connect next 3rd card, if see turn off system, connect 4th card, if see turn off all, then connect last card and wait little if system will find it... sometimes this worked for me with those mobos

2) other thing. Risers - try to use other risers (might be malfunctioning...)...

3) With btc mobo as well I will suggest you to try this:
- remove both molex connected to mainboard (yes no powering mobo anymore from this mobo special feature...)
- connect all cards and attach them to RISERS molex as supportiing powers (instead of the mobo molex).
Explanation: I had one fight with btc 81 and somehow it didnt allow me to connect more then 3 cards even as visible ... like mobo was all time blocking it as not enough possible power were supporting from those 2 molex (yes wired, stupid but for me helped - honestly :/)


Pretty thats all from what I would start in my case
I have 4 such a mainboards and had as well some fights with it... its like never can be best

good luck

[Undefined31415]

I swapped out some of my risers (still don't know which ones were defective though ) and got them all running under Ubuntu 13.04, without the A1->B17 shorting or unpowering any risers.

Thanks for all the help everyone!