Update your cgminer Proofer.
There was some minor glitch in the code resulting in the "Pool not providing work fast enough" condition being falsely triggered right after having received an LP message.
I believe Conman mentioned this specific glitch lately in cgminer thread.

Pools will be the death of us all... and I regard Deepbit as the Mordor of all pools - can't expect anything good with all that amassed hash power.

Translates to:

Not what you want to see, I reckon.
That's the worst-case scenario, to be sure, but that's how algorithms should be always analyzed.
If you evaluate the best-case performance or even the expected performance, you might miss a situation where the algorithm falls flat on its face when slightly abused.


The second approach seems safer. Even though it doesn't give the big miners a huge incentive to set up donations, prioritizing them regardless is the way for the whole pool to be more efficient.

The exact difference in mining speed between a stock 5850 and a stock 6870 is 3,5%.

I know it's old. Still, the 5850 is hard to beat as far as mining is concerned. Games will likely prefer a more recent card though.
Not worth going with that specific card 5850 you linked to IMO, it's bound to be loud as heck under full load.

If I were to choose, I'd go with this.
Three massive fans will keep this card cool and quiet even with some crazy overclocking. The superior cooling system does come at a premium though.

24/7 mining generates a lot of heat, more than typical gaming will generate.

But you ARE performing useful math - not only does mining "unlock bitcoins" as you put it but it also keeps the whole bitcoin universe secure.

As to your question, of course there are ways block chain hashing can be combined with other useful applications.
Care to come up with and implement one?

Do yourself the favor and grab a 6870. It's just more efficient at mining.
If you're going to start mining, at least let's make it a commendable start.

In fact, an old 5850 would be a bit faster than a 6870 but it's increasingly hard to get those in good shape and with manufacturer's warranty.

Voltage or Power-tune? Those two are completely orthogonal values and mustn't get mixed up.

Biggest-miners-first is a tried and true algorithm beneficial for the pool and its operator.
P4Man already made his point about donations and I believe he's right.

If you choose to proceed with incorporating donations into the LP system, Doc, make sure there's a hard limit as to where donations can move any miner on the priority list.
Don't do something bone-headed that might negatively impact the whole pool (*cough*Triplemining jackpot farming*cough*).

You wouldn't like to have 150 CPU miners appear out of the blue and ruin your LP system by setting their donation to 50%, right?
They aren't gonna get any work done anyhow and your LP system is hosed.


Thanks for taking a good care of us, Doc.

Nearly there.
Just keep in mind that not every mining kernel currently works with 79xx cards.
DiabloMiner is reported to support GCN architecture flawlessly.

Not quite. What you are talking about would be the Powertune slider.
This doohickey doesn't change the voltage but changes the maximum amount of power the card will use at driver level.
That's nowhere near as useful as being able to change the voltage directly because powertune impacts the hash rate to some degree.
You may set it to eg. -10% in order the lower the temperatures.

Once again I remind you that there are better tools for fine tuning your cards than AMD Vision Engine Control Center and Overdrive.
No need to feel sorry, just do as any other newb does and do some research in Hardware and Mining Support.

As I said, I have no experience whatsoever running cgminer on Windows.

Try those Overdrive-replacements first. This should allow you to make better use of your cards.
While your (hopefully) undervolted cards will being tested for stability, you can mess around with setting up cgminer.


Undervolting a GPU means lowering the voltage at your GPU core.
Almost all cards will run without problems at lower than factory-set voltage levels.
The reason for this phenomenon is, the lower the quality of the GPU core is, the higher voltage is required to run that particular chip. Manufacturers set voltage levels for the whole families of cards based on an absolute worst-case scenario.

Power usage (and thus the amount of heat produced) diminishes by voltage squared, hence relatively minor voltage reduction can have a tangible effect on power efficiency and temperatures.

I already touched on it here: https://bitcointalk.org/index.php?topic=60593.msg706110#msg706110

That's precisely why I said give MSI Afterburner a try. It's a better alternative to Overdrive, free of charge.
Another widely-used and highly-regarded program is Sapphire TriXX

...and preferably sooner rather than later as this malfunction might damage your USB controller circuit.

Firstly, it's more like doing the backup every 100 actions.
No matter whether you receive funds, send funds, or generate new receiving addresses, each of those actions uses⁽¹⁾ one of the pre-generated keys.

Secondly, you can run bitcoin-qt with the parameter -keypool=<n>  to tweak the pool of pre-generated keys. Sane values are <1000.


Notes:
(1) Actually, receiving funds only uses a key from the key-pool if the funds are sent to the address currently listed as "my address". Receiving bitcoins with any other previously-generated address does not influence the key-pool. Therefore, you will generally be safer than you think you are as far as using very old wallet backups is concerned.

Good for you but still that's 3% fee for the most primitive, proportional payout scheme.

You'll be a sheep the pool hoppers thrive on. If that doesn't bother you, be my guest.
As I said SMPPS, PPLNS, PPS, and DGM payout schemes were invented with the explicit purpose of being immune to pool hopping.

No payout scheme should influence your revenue in any way. Some being more variance than others but all the differences average out over time.
The only things which really matter are pool fees and stale share percentage.

Some pools introduce fancy features to lure users: Triplemining has a 1 BTC jackpot every week. The only problem is, being one of the pool's 130+ active users there is no reason you should expect to win the jackpot this year. As I said, it's more of a lure than a tangible advantage.

Some work will surely need to be done:
That temp is dangerous in the long run.
100% fan speed will wear the fans out fast.
1375 MHz @memory is just a waste of energy. Lowering the clocks to 300MHz should drop the temps significantly all by itself.
You might wish to upgrade your PC case with a few good fans. Which case are you using BTW?

I strongly suggest you ditch AMD Vision Engine Control Center and Overdrive and give MSI Afterburner a try.

Yeah, I agree that using cgminer requires putting the thinking cap on and going into the full-nerd mode (also known as text-mode)  
Once you get it working though, it's extremely handy.

It's called shock treatment. Just what the doc prescribes to guys with 30 posts under their belt authoritatively stating that a 1500W monster can't pull 950 Watts
My point wasn't to be harsh and nasty. I needed to stop the disinformation from being spread around.

Thanks for the clarification Jedi. Getting accurate info from the actual developer is more then I could hope for

I don't recommend you use Deepbit.
However good/stable they are, they can't possibly make up for the 10% fee they charge the PPS-mode miners.

Eligius is a SMPPS pool, therefore you will get very steady payouts - every single share you send will be paid for.
While Deepbit pays you 0.00003597 BTC per share, current reward on Eligius is 0.00003997 BTC.
How about you underclock your GPUs by 10%? No? Didn't think so. Then why stick with high fee pools?

I'm currently mining at Bitminter and have only 0.13% rejected shares. That should put your 1.63% in perspective.
Using BitMinter, you have to get ready for some variance. There can be days when no block is found and you get nothing.
That shouldn't matter, however, as over time expected revenues from both Eligius and BitMinter converge on the same value.

They're not supposed to be 50°C, I was just being sarcastic at your vagueness  
Keep'em below 80°C at all cost. Underclocking will help here. High 60s - low70s would be optimal.

If possible, avoid fan speeds exceeding 70%, though.
Higher speeds yield diminishing returns and you'll wear out the fans in a few months.

You said your memory was at the lowest setting. Can you tell me exactly what speed that amounts to?

My previous post has been updated with some general undervolting tips.
All my miners are running Linux and I'm using cgminer for the undervolting. Not sure how it's done on Windows.
I suggest you give cgminer a try. This miner is capable of dealing with multiple-pool mining, overclocking, undervolting, and temperature control all by itself. Not bad for a single piece of code.
If cgminer fails to change the voltages, try AMD's CCC.
If CCC doesn't provide an option to undervolt, you're gonna have to use software like trixx or afterburner.