Well... Isn't share submission somewhat related to time? My computer is running 24/7, so I don't see why I'd get less shares on longer blocks? The front page links to http://forum.bitcoin.org/?topic=1976.msg50002#msg50002
, where Slush explains it is a score based system. Are you referring to another link?
I'd be interested in your 6950 configs. As I said, I'm a casual miner, and I mine on my primary rig, so I don't want to push the overdrive too hard (I'm F'ed if I burn it). I'm with -v -w 128. I have one of those new low cost single Bios Saphire 1GB 6950 cards, whose shaders can't be unlocked (at you flash with no safety net). I've pushed the OC up to 840Mhz, where I mine at 330MH/s, with the card @ 79°. Any way to get more bang out of it without pushing the clocks further?
I was talking about http://mining.bitcoin.cz/
which is Slush's Pool's website. I don't 100% completely understand the math behind it myself, so I hope someone else replies to this thread and explains it in-depth.
My 6950 setup:
Core clock: 1,000 Mhz
VRAM clock: 400 Mhz
CCC OverDrive: +20%
Core voltage: 1260 mV (I'm still tweaking this because I think it can go lower)
Temperature: 70 C
Fan speed: 70~80% (depends on time of day; ambient temps are hotter mid-day)
Arguments: -v 2 -w 128
The card I have is a Sapphire 2GB reference card, which is basically a 6970 with some of its shaders locked. I patched my BIOS to unlock the shaders, so it's essentially an overclocked 6970. VRAM isn't really used in bitcoin mining, so underclocking VRAM makes your GPU require less voltage. This is also my gaming rig... all I have is a crappy backup laptop, so I'm screwed if this burns out too lol, but 70C is a fine temp. I highly recommend forming your own fanspeed curve based on GPU core temp. You can do this with Afterburner or Trixx easily, in the fan control settings. That way your fanspeed will be dynamically adjusted based on your GPU core temp.
Oh, and open your case and point a table fan at your card. Not directly at it, but at an angle. My fan is on 'low', angled to blow the heat from my GPU out the back of the case. Having my case closed up trapped all the heat inside... the extra fan allowed me to overclock a lot higher.