I have an older system I use to mine, with 1x PCIe16x, and 2x PCIe 1x. The system has a 5 month old 720W PSU, Core2 Quad processor, and 8 GB RAM (I can go up to 16GB DDR2, but DDR2 right now is a little costly.)
I was mining fine (12.8 drivers) with two 7950s (one in the 16x, and one on a powered 1-16 extender), and decided, since I had the spare PSU capacity and spare PCIe port, to use a 1-1 extender I had on hand and also get a 16-16 extender, and another 7950. My thinking was three PCIe slots was good enough, and since each card only uses 200W, I still had enough for the system to run.
Ever since I installed the third card this evening, when I run CGminer, the graphics driver craps out and recovers, GPU0 goes permanently offline and doesn't recover, and GPUs 1 and 2 mine anywhere between 50-80 percent their capability.
Am I running into a RAM issue (since each card is a Gigabyte 7950 3GB, do I need to have 10+ GB RAM)? Or is it like someone else said, an overclocking issue?
{
"pools" : [
{
"url" : "
http://pxc.allpoolz.com:8080",
"user" : "user",
"pass" : "x"
},
{
"url" : "
http://phoen01.phenixpool.com:9500",
"user" : "user",
"pass" : "x"
},
{
"url" : "
http://btb.ltcoin.net:2222",
"user" : "user",
"pass" : "x"
}
]
,
"intensity" : "20,20,20",
"vectors" : "1,1,1",
"worksize" : "256,256.256",
"kernel" : "scrypt,scrypt,scrypt",
"lookup-gap" : "0,0,0",
"thread-concurrency" : "21712,21712,21712",
"shaders" : "0,0,0",
"gpu-engine" : "0-1190,0-1190,0-1190",
"gpu-fan" : "0-85,0-85,0-85",
"gpu-memclock" : "1450,1450,1450",
"gpu-memdiff" : "0,0,0",
"gpu-powertune" : "0,0,0",
"gpu-vddc" : "1.206,1.206,1.206",
"temp-cutoff" : "95,95,95",
"temp-overheat" : "85,85,85",
"temp-target" : "75,75,75",
"api-port" : "4028",
"expiry" : "120",
"gpu-dyninterval" : "7",
"gpu-platform" : "0",
"gpu-threads" : "1",
"hotplug" : "5",
"log" : "1",
"no-pool-disable" : true,
"queue" : "1",
"scan-time" : "60",
"scrypt" : true,
"temp-hysteresis" : "3",
"shares" : "0",
"auto-fan" : true,
"auto-gpu" : true,
"kernel-path" : "/usr/local/bin"
}
