have to be careful using 16x to 16x risers with a jumpered slot, I just fried a 16x slot

What motherboard are you using?

I run Windows 8 w/ 13.1 & 2.8

Im running a Lepa G1600 and working on trying to get 5 - 7950s working, up to 4 ATM, on it

the Boost Edition is the $320 and runs at 960 / 1250 stock

i hit 1050-1100 / 1350-1450 with these cards

I wont debate the Win 8 vs Win 7, I have used both 8 and 7 before for mining rigs, I have seen no problems nor heard of any legit information saying theres a problem with 8. From what I have read in other tech site not forums, is there is no difference in the kernels as far as GPUs are concerned besides a few small additions hence why most drivers didnt not change from 7 to 8

I have tested all the cards in the primary pcie 16x slot, and ran them on another computer of mine, all cards show up in both systems Device Manager and in CGminer they all mine

The PCIe slots are Gen 2 and function as 2x16x, 1x8x, and 1x4x

In other posts these motherboards have been said to have 6 cards running on them.

I AM ADDING A 5 LTC bounty to this

The system specs for above, Im helping Pete assemble this rig.

AMD FX 4100
MSI 990FXA-GD80 v2
5x MSI R7950 Twin Frozr 3 Boost Editions
16GB Crucial DDR3 1600
Lepa G1600 PSU
2 - 1x to 16x powered risers (I have more on order)
and a bunch of 16x to 16x non and powered risers

I have tested the voltage levels, with a power supply tester all are within spec
I am just running the cards when I got 4 to work in CGminer at stock speeds.

we are running Windows 8 x64
I haved tried AMD 12.8, 13.1, 13.4 drivers
AMD SDK 2.7, 2.8
CGMiner 3.1.1

I have disabled everything that is not needed in Motherboard BIOS
I have jumpered the 1x to 16x Risers, and I have tried with a 16x to 16x jumpered,
every conceivable combination of Riser cables in the PCIe 16x and the PCIe 1x slots.
I have the cards in my test bench raised above the motherboard, they are close together for right now, but I will build another chassis to spread them out.

In referencing the cards

#1 is in the Primary (Top Most) PCIe 16x slot
#2 is in the Seconday PCIe 16x slot
#3 is in the Third PCIe 16x slot
#4 is in the Fourth PCIe 16x slot
#5 will be used in one of the PCIe 1x Slots


I start out with 2 cards in the primary 16x slot and secondary 16x slot and once that works I add the 3rd card in the 3rd 16x slot
The bottom slot (16x) seems to be a pain, as getting it to show up in Device Manager sometimes it does and doesn't, after I get the third card to work
I have got the 5th Card in the top most PCIe 1x slot to show up in Device Manager, but the 4th card wont show up, and or vice versa

Before I try CGminer I look for the cards in Device Manager, and we Pete and I have read tons of Posts,

says the man with Chinacoin as username

Hmm?

a good case flows air better than an open air scenario, but the problem is spacing the GPUs apart which becomes an issue when you use more than two cards as most are double slot cards and if theyre stack right next to each other they will get hot

ok after some research thru the forums
I installed cgminer into a new folder and I running it seperate than my BTC one, not sure why but requires a tiny space so

added the 2 commands to the .bat file


ran cgminer for a few minutes and got my thread concurrency from the .bin file name

now coinotron is reporting ~560KH/s much greater than 80KH/s

tweaking my gpu and memory speeds and now my rig is using 4gbs of system ram

I am getting the same types of results when I switch from BTC mining with cgminer to LTC mining.
On my test machine with 1 7950 cgminer shows 630KH/sec but coinotron, notroll, and kattare all show no higher than 80KH/s

I used to love PC PnC PSU until they got bought by OCZ now I use Corsair and I love my AX1200i

LTC scripting does use RAM
https://bitcointalk.org/index.php?topic=163306

Solar Panel? lol you'd spend a fortune to get one big enough to use even if you lived in Phoenix AZ

Power Rates depend a lot on where you live in the world, I am currently paying .0803 kw/h + taxes

Of course this is all my opinion:
Mobo: good
CPU: good
GPU: good but i prefer the MSI R7950 TF ed
RAM: Good but spend a few xtra bucks on the 2x4GB DDR3 1866s if nothing else but for resale value
PSU: buy a gold or platinum for the extra wattage you get, i personally love the new i series (AX760i /860 /1200) from Corsair the monitoring software saves me a lot of time when i am OCing plus they're highly rated PSU's and you get more REAL watts out of them, that Rosewill will only give you 850w usable under full load

manufacturers wattage ratings are like car manufacturers EPA gas mileage ratings, usually not that accurate especially under >85% load

borrow your neighbors >

AMD 990 Motherboards brands is your choice, but my preference has always been ASUS or MSI

RAM depends on what you are planning to mine. BTC mining is just GPU dependent so it doesn't really need a good CPU or RAM, LTC mining uses your RAM and from what I have been reading requires about 8 GBs id spend a few bucks and buy some Corsair DDR3 1866 sticks, if for nothing else better resale

I have been getting 605 MH/s (BTC) and 640KH/s (LTC) using the MSI R7950 Twin Frozr at 65C @ 4500RPMs, MSI uses good quality parts and their cooling is very good ((see link in post above)) and also remember these suck about 250w of power each

if you are using 3 or 4 cards you will need to use PCI-e riser cables see http://www.cablesaurus.com/

I only use Corsair PSUs as I have had a great track record with them for myself and my customers, I build/repair systems as a business, plus I love the new i series PSUs being able to monitor the voltages live makes OC'ing a shit ton easier.

Another thing to consider is most PSUs are rated at 80%+ so if you have a 850w PSU that's only 80% certified its only going to give you 850*.8 = 680 under full load, so always check your PSUs rating, as once cheaper PSUs warm up their efficiency drops like a rock. So look for Gold or Platinum PSUs

Windows is easier in my opinion (i know windows well) but costs $100, where if you know Linux it can save you money

LOL I was wondering why I couldnt reply, and I assumed it was IE10 since that damn browser doesnt like anything. T