OK. Hence why you are using 2400 thread-concurrency i.e. 5 x 480 =  2400

The info. in the cgminer read me suggests to use 4 or 5 times shaders for best operation. This series of card seems to function better at 3200 and above. I in fact have mine (stable) at 3680.

cgminer -o --scrypt -I 14 -g 1 --thread-concurrency 3680 -w 256 --auto-gpu --gpu-engine 900 --gpu-memclock 800 --no-submit-stale

GPU overclocked by 100 and default memory clock. N.B. These are not my fully overclocked settings, these are safe / stable settings.

Once you have installed MSI Afterburner - try pushing the GPU Core Clock setting up by 5 or 10 to find a stable (highest) value, where you don't see any screen or graphic glitches etc. The higher up you get just add 5 each time instead of 10. If you see a screen error then quickly move it back down by 10 to 25-ish and that will probably be close to the optimal value. You can re-set it and do the same for the Memory Clock and then try both settings together, again reduced by around 10-25 each. If the screen locks up, then you need to hard reset your PC (by holding down the power button) and waiting 10-30 seconds before a re-boot. You have a good amount of system RAM, so you should be OK to move the sliders back down, if your quick, before a full freeze-up (also give the system 30 seconds to respond if this happens).

You can't cause your GPU any real damage by doing this, only increasing voltage etc. will potentially wreck your card or make it unsafe.

I was incorrect in my post above and your default clock speed on that card is also 800 MHz ? So, around 900 to 920 is probably the max. ?

Please post your results so that I might try to help you further. Also, bare in mind that your card does not have a fan, so watch the temp. It should be OK though as it looks to have some crazy heat sink.

This is interesting for me in regards to something that I'm working on with system RAM and scrypt mining. 

Thanks

Sure. Please download GPU-Z - http://www.techpowerup.com/gpuz/ and let me know how many shaders this card has.

I have a SAPPHIRE HD 6670 2GB DDR3 in one scrypt mining box that I have.

See: http://www.sapphiretech.com/presentation/product/?cid=1&gid=3&sgid=1088&pid=1218&psn=&lid=1&leg=0

I brought it recently because I wanted to test some stuff with scrypt mining which is very RAM intensive.

This card has 'Hyper Memory Support' See the chart in the link.

Up to 2.8 GB Memory Support with Hyper Memory
Enjoy the big memory frame buffer with Hyper Memory Technology.
Hyper Memory Support Matrix Under Windows Vista and Windows 7.

On Windows 7 x64 I've managed to push this card to around 130 kh/s (stable-ish) to 145 kh/s un-stable with some serious overclocking and messing around with the voltage settings and some other stuff, which is generally unsafe to do and not to be advised.

Interestingly enough it struggles to get above 90 kh/s in Linux Ubuntu, even with the (correct) same drivers and overclocking. In other words the Hyper Memory Support can really make a big difference when scrypt mining.

Your card: http://www.sapphiretech.com/presentation/product/?cid=1&gid=3&sgid=1088&lid=1&pid=1240

Has a faster clock speed and more video memory, although it doesn't have Hyper Memory Support. However, if your using the 'default' thread-concurency of 3200 ? then I can probably dig you out some settings to improve on that using cgminer.

Again, as someone mentioned above, in many respects its almost best to under-clock the memory and just over-clock the CPU to save on power and get the best ROI etc. There will probably be a ratio for this card, where under-clocking the memory, won't affect the highest possible hash rate, once you have found the optimum thread-concurrency and the highest most stable CPU overclocked speed.

You probably won't get much above 120 kh/s tbh, but correct optimization will save power and can churn more shares!

Sorry for delay, got some minor problems. I hope I'll upload the QT client in 15 minutes.

given the REC mining rate and interests, the price should be higher than 1LTC/10K REC, probably 1LTC/1K, I would expect.

want to buy some realcoins, 20k for 1 LTC. anyone interested, please PM me.

So is this thread stopped or continue.............?

Sorry, I lost my brother this week, so I have been busy. I will get back to this eventually, but here is another thread to get free DVC
https://bitcointalk.org/index.php?topic=194307.0