Last barrier was at around 10.25 the last time people panicked. I think that was a month ago.

After that it rebounded pretty fast, then it got stuck at 16-17 for a long time.

That stream of work theory definitely makes sense.

Any idea why it would only happen while mining though? The load is spread pretty much 50/50 in everything else that stresses the GPUs. During mining both cores have same hash rates but only the 2nd core overheats.

Or maybe it's GUIminer/Poclbm?

Can you post back with results? I'm thinking AMD powertune is crippling the card if OC switch is not on.

I get pretty much the same results as OP, very noticeable boost from the standard 330-340mhash per core to at least 400-420 (with the exception of the temperature thing)

However, even at same clock rates, OC switch in position 1 "unlocks" the speed. In position 0 (default) the hashing rate just wont go past 370mhash/s or so.
So the switch could be doing some sort of power limiting on some 6990's.

I don't think you read mastergamer's post.
The voltage regulators are cooled with the air stream the fans take in. The slower you run the fan the hotter they get.

If you are overclocking a card, your VRM is overheating in an exponential scale the more voltage you add.

A graphics card will probably never die in normal use from a toast GPU just as a CPU chip wont.
It might weaken from overclocking due to electromigration but it will never die.

It's the capacitors, VRM, chokes and other components that are the most likely to break.

I stand corrected. Price doesn't correlate with quality in PSU's.
There's a lot of expensive no-name crap out there.

It's GPU specific. Some can be pushed as high as 1075mhz, and others will start freezing even at 910.

If it's a 'sour GPU' so to speak, then it simply can't go past a certain point no matter how much voltage is applied.
Though usually the premium ones are binned for the top of the food chain (best 5870 cores to the 5970, best 6970 cores to the 6990)

The card wont fit into the x1 extender on it's own, the end has to be sawed off.
Some sellers already do it for you before shipping though.

Slush and Tycho got rid of their DDoS attacks back a month ago with the use of blacklisting/whitelisting IP's based on 'suspicious', 'normal' and 'repeat' traffic,
so that's one "simple" solution you don't need to pay hundreds of thousands of dollars for.

For example, slush's pool was initially only allowing people to connect that were actively submitting shares to the pool lately.
Pretty fool-proof if you ask me.

If they make a power-efficient (I'm thinking 45W) APU that can put out 80-120mhash/s with 400-600 Radeon 7xxx series shaders, CPU mining will be worth it.

Granted it's not much in daily BTC, but it will pay to keep the processor mining, unlike now.

Tried to 840mhz ages ago, works great for the other core. Also puts temps in games etc. at about 65c for both cores, both equally loaded to 99-100%.

2nd core still goes up to 99c while mining.

And that's why you should spend the extra money on a real PSU instead of skimping out a few bucks & ruining the rest of your PC

Kept. The 50BTC itself is distributed. Deepbit has the highest fees of any pool in the 'industry'.

I only keep some workers there because it's practically guaranteed income with next to zero variance (avg. -+5% daily) due to it's huge size, making it worth the fees.

Seasonic, Silverstone and Corsair make the best high-end power supplies. Not subjectively speaking; Specifications wise. Everything else is practically junk compared to the top-line 850-1000W+ PSU's of those companies.

Enermax has also top notch guts under the hood, though is a bit less known outside the US.

http://www.hardwaresecrets.com/

Ok, good to hear it's normal then. I do run 5 other 6990's since March but none with this big temp fluctuations.

Fans are constantly at 90-100% due to that one core. The 1st gpu temp is just as it should be around 70-75, but the 2nd goes nuts.
And it only happens while mining so it can't be misapplied thermal paste etc. (temps stay within 1-2c of each other in different apps)

How long of a round are you currently going on? I don't have miners at Eligius atm.

lol

Take in account the current & next difficulties (1.3-1.6m).

They are brutally hard for small pools in terms of variance.
Sure, it evens out in the long term, which is months and years statistically.

It doesn't even out in the short term. A single difficulty can change in 7-10 days.

If your pool does under 50ghash/s, your earnings might drop to literally zero if the pool has bad enough luck (i.e. it might only find a single block during a difficulty level, or none at all)

The larger a pool is, the better it's protected against massive luck swings caused by raising difficulty level & variance.
Pool luck varies about 5-15% at the most on giants like Slush and deepbit.

On pools below 500 ghash, there are daily swings upwards of 20-50% or worse.

A lot of countries can't join LR and Dwolla is for USA users only.

What other international options are there if you need the cash in your hands?

Maybe. But I wouldn't prostitute my grandma for 3 dollars like the people begging "Foodstamp".
Or even 30.
Or 300.

Maybe 300.