To all those who pointed out my guiminer problem was because I had all three miners pointed at the same gpu, you were right - I was
smart enough to set the GTX 480's up correctly but forgot to check the same when I cloned 2nd & 3rd gpu from my first 7870 miner.
guiminer connects to stratum.bitcoin.cz:3333 ok, and all three are putting out 360+ MH/s.
I'm happy that you're getting 360+ MH/s on your Asus HD7870DC2-2GD5-V2 gpus. The Fedex dude was just here a couple of hours ago to deliver two of exactly the same cards that you have to replace a couple of mining-challenged Nvidia GPUs on an old gaming rig. I have come to the conclusion that generally, AMD cards that are moderately OC'd, usually hashes around 26% of the number of stream processors. So I figured that I would be getting around 265 MH/s (26% of 1024 stream processors) out of each of these cards. At what clock are you getting 360+ MH/s with, may I ask?
7850 - I got about 330MH/s - 1200Mhz
7870 - 430-450MH/s - 1215Mhz
7950 - 540MH/s - 1150Mhz
7950 - 520MH/s - 1100Mhz
That's what I've been getting returned the 7850 now running two 7870, two 7950.
Thanks...and please see "Edit" to my original post (eyes too slow, fingers too quick). Anyway, are those clocks sustainable? I imagine that you must be either in a cold region or in a very well-cooled data center. The only time I get up to such clocks is when I try to do a quick benchmark...and during winter...and then it dies.