Help adding another HD7770

[tyrion70]

Hi All,

I recently added a second HD7770 to my trusty mining rig (if you can call it that :p). Its now running a smooth 370MH using only 250W, which actually surprised me since it was at 170W with 1 HD7770.

Now I'm thinking of adding a third HD7770. However my mainboard has only 2 PCI-E slots. It's a ASUS P5K MB (with a Q6600 CPU).

The question is; what mainboard do u advise that is able to support 3 HD7770's? Before you all say buy a 7970 instead; prices here in Holland for those cards are idiotic.. A 7770 costs me 110,- while a 7970 starts at 370,-. With the reported MH/J and MH/s it would only cost me to switch to 7970's. Also my PSU is 550W so I'm not comfortable sticking 2 7970's in it without replacing that as well (which would make it even more expensive).

TIA,
Tyrion70

[avive]

Im using Gigabyte GA-Z77X-D3H

http://www.gigabyte.com/products/product-page.aspx?pid=4325#ov

How do you monitor the power?

[tyrion70]

Hmm.. I thought my english was good, but no way to explain this..

I use this: http://tuinenbouwmarkt.nl/rce-1106cresta-waterpasinstrumenten?utm_source=Google%2BShopping&utm_medium=Winkelvergelijkers&utm_campaign=Google%2BShopping&gclid=CKXr9JTm3rYCFQm33godKUoAqw (Dutch site)

We call it an "Energiemeter" in Dutch.. You just plug it in and plug your PC or other equipment in the meter and voila

With regards to the mainboard; It says it has one PCI-X4, one PCI-X8 and one PCI-X16 slot, doesn't that influence the speed?

Thanks

[avive]

No influence on the speed.

I have one 5870 which makes 350 Mhash
and two 5830 which makes 500 Mhash together

Im using Seasonic X Gold 850W
I need to check the actual power rate in full load.

[tyrion70]

OK Cool; I'll see if I can find that MB somewhere here

I'm not sure where ur from but in US I found:
http://www.walmart.com/ip/Stanley-Energy-Meter/14146175

Maybe that helps..

Rgds

[FiatKiller]

You can use powered risers to convert a 1X slot to a 16X. Most common source is cablesaurus.com