Sorry, can't replicate your crash.

Created a new wallet, encrypted it (client restarted), added a couple send and receive addresses, changed passphrase, added a couple more addresses.
Using the old passphrase only made Bitcoin-qt 5.1 grumble about being unable to unlock the wallet and give me that "Don't remember your password, dummy?" look

As to keeping backups, here's what I recommend:

(1) If you haven't already, download and install TrueCrypt. It's a great, free, and completely open-source piece of software with a great GUI.
(2) Encrypt your wallet file(s) into an encrypted archive ¹. Please use a VERY long passphrase. Make sure you don't forget the passphrase though ^^
(3) Propagate the encrypted archive. I send myself a copy as an e-mail attachment. I keep another copy on my smartphone. Yet another on my file server. There's a copy floating in the internet cloud... a myriad of options to choose from.

This way, whatever happens some copies will survive.
Should a third party obtain a copy of the encrypted archive, there's nothing they can do with it.

The last piece of advice is, never keep all your bitcoins in one wallet if you have a sizable amount of them.
Divide your bitcions into a number of wallet.dat files and encrypt them all.

Good luck with the recovery.



(1) A neat trick is not specifying any file extension for the encrypted archive. Mine exists as a file named something like b9e6c89a. There's nothing in the file structure which could identify it as a TrueCrypt archive, there's pure randomness inside. Have at it, you evil-doers

Let's change our approach to the recovery a bit.

Ninja, have you had any success with your backup drive?
Does it spin up when powered up? Does it initialize? Is it at all visible to the OS or BIOS?
What exactly happened to that drive, did you drop it?
If the drive was indeed dropped, disregard my advice regarding software recovery - if the head got killed, it'll never pull any useful data off the platters.

Try connecting it to another machine (perhaps with a more patient disk controller).

If the BIOS sees it, there's a good chance you might be able to recover your data using data recovery software.
Spinrite might do the job, it's a very tenacious piece of software.
Be advised though, the recovery process has been known to stretch into weeks on some damaged drives, although for me it was never longer than a couple of days tops.
I'm in no way associated with the author, BTW, just a satisfied user.

Was working fine earlier this evening... dead now.
Sad as it is to say, ArsBitcoin is dying a slow and painful death.

Howdy!

Ad 1. Yes, the only incentive will be transaction fees. That will be plenty provided bitcoin universe is large enough (at least an order of magnitude more transactions than we currently have). Please note that we're not running out of mineable bitcoins any time soon.


Ad 2. Not gonna happen. Difficulty will drop if miners aren't strong enough, that's the beauty of the algorithm. It might be fair to criticize bitcoin's inefficient use of electric power due to the approach to difficulty but that's the price you pay for the reliability, flexibility, and independence from a trusted third party.
EDIT:: I think I misread your question. DeathAndTaxes is right on point, as he usually is.


Ad 3. There are your private keys ( a pair of these for each of your address) (in fact there is a whole pool of them (100 by default) just waiting to be used), your transaction data, reserve keys, some preferences and versioning info, saved recipient addresses, ...a lot of good stuff inside that file ^^


Ad 4. That's correct. Should the number of active nodes be decimated, the bar for successfully attacking the network would be lowered accordingly. Mind you, taking a significant portion of nodes is a non-trivial task. Attacking mining pools is of limited impact as all serious miners configured their rigs to switch to solo mining if they can't connect to any pre-defined pool. The network has successfully coped with massive DoS attacks in the past.
Any serious and devastating attack would have to exploit some vulnerability in the bitcoin software.


EDIT:: Merry Christmas DAT!

I'd like to make one point clear:
All current GPU miners are heavily optimized for VLIW4/5 hardware.

Isn't it reasonable to expect that GCN cards will do much better with miner optimizations?
Just look at the performance boosts we've had with newer versions of the current kernels.

10% performance increase over VLIW5? Rest assured, the 7970 will kick ass yet.

As to the 78xx series being THE series for bitcoin mining, they are much more familiar to us thus seem better.
Wait for the software to catch up.

So, the cause seems to be your poor, overwhelmed CPU.
That constant 30% CPU usage is just Windows... that's why going Linux was among the first choices I gave you.
I already gave you some ideas as to what features you might wish to disable.

If you wish to pinpoint the source of the CPU usage more accurately, it's gonna get a tiny bit technical:
 - Install Microsoft's Sysinternals' Process Explorer ⁽¹⁾
 - Run it as root; it will show you a lot of good stuff, including CPU usage by different windows services and drivers.
 - Post a list (or a screenshot) of what's going on there, under the hood.


In my career I've seen a lot of astonishing mishaps; one cheapo laptop hogged the CPU by having its mic constantly on and doing additional postprocessing to the captured sound... the louder its environment, the more CPU was being used


Links:
(1)     http://technet.microsoft.com/en-us/sysinternals/bb896653

I can think of a few reasons why this mess could be happening.
Please start troubleshooting at 1.

[1] Overwhelmed CPU
Is this a dedicated mining rig?
A dedicated windows-based mining rig should have all the useless (in this context) housekeeping tasks turned off: no defragmentation, indexing, power saving, switching off unused hard drives, no automatic updates and by Jove don't ever use an antivirus on a dedicated miner.

That's a pretty weak CPU so if you were to use this machine as your desktop PC, the mining speed will suffer if the CPU can't keep up. Poor mining speed due to a running web browser is an ubiquitous and long-established fact of life on "mining-optimised" ( ==weak CPU ) machines.

Do you think you could monitor your CPU usage in addition to the GPU stats? CPU temps?
See what the CPU is doing when the mining speed drops happen.

[2] Faulty BIOS
You're running the most recent version, right?

[3] Motherboard too weak to provide enough juice
The MSI 890FXA-GD70 does not seem to sport the additional peripheral connector to provide more current for multiple GPU configurations.
Did you try taking one of the cards out?

Alienate Bitcoin100 supporters? Not happening man.
That's why I said "I'll pass this one" instead of "Get me outta here"  ^^

Rassah, I read the other thread and you seem to be doing one hell of a job. Big thumbs up.

Not really my cup of tea. Campaign donations just ain't what I signed up for.
Sorry, Bruno, I think I'll pass this one.

Did you install the chipset drivers and the rest of the myriad of drivers bundled with your mobo?
I don't recommend you install manufacturer's utility programs but please make sure you have no missing drivers.


Yeah, Debian is a Linux distro. Ubuntu is based on Debian, in fact.

Obviously something's off as most dedicated bitcoin mining rigs are not only based on AMD processors but on the cheapest and weakest AMD cpus.

Please double-check your bios settings on that AMD mobo, mayhap some elusive power-saving option remains switched on?
You made sure Crossfire is turned off, right?

Is that a windows-based rig? Which version of Windows? Make sure Aero interface is turned off, ok?

What's the CPU usage? Idle and mining.


...or just make a clean Debian install...

In any linux system, there are a bunch of log files in /var/log

No need to browse through them to check for a machine restart though, just use the "uptime" command.

You sure your thermals are ok?

Having taken some time to dig through all of Intel's docs, I admit I may have been more concerned that necessary.

What's bugging me is, it seems that every single technology portal specifying the maximum temp for the q6600 made the same mistake I did:
opened up the latest version of Intel's specs -> thermal -> table 28 or table 29 depending on the TDP.
The ONLY thermal spec intel bothered to provide there is the TC value.
TC is the CPU temp alright, except it's measured on the IHS and hence lower than TJunction.

Since TC is usually about 10 °C lower than TJ, Soraka is at least 20 °C away from TAbsoluteMax.
He's in the green, he's a-ok.

My original post has been corrected.

Thanks for a great, technical discussion, and finally untangling this mess.

Hereby do I proclaim us Q6600 Experts.
P4 gets the Chief Q6600 Expert title.

BTW, your link seems to be dead P4 ( http://intel.wingateweb.com/taiwan08/published/sessions/TPWS002/FA08%20IDF-Taipei_TPWS002_Nov_1006.pdf )

Precisely. We need organizations to embrace bitcoin and yet debate whether or not we should donate?
As a member of bitcoin100 I say just send them the darned coins.

You already told us you have a Q6600, Soraka. Ok.
There have been two versions (revisions) of this CPU: B3 (SL9UM) and G0 (SLACR).

G0 is the 95 Watt version while B3 is the earlier 105 Watt version.


To get this info, you need to either use a program like cpu-z or read the processor's serial number manually.
I'm aware that some (very few) BIOSes might display this info as well.

Soraka, can you download cpu-z ⁽¹⁾, run it, and post the results? The info you need is the "Revision" field.



(1)  http://www.cpuid.com/softwares/cpu-z.html

I don't mean to be rude, P4 but please try reading Intel's spec, ok?
These temps are NOT deltas!

Quoting from the aforementioned spec sheet
{
  In the event of a catastrophic cooling failure, the processor will
  automatically shut down when the silicon has reached a
  temperature approximately 20 °C above the maximum TC ⁽¹⁾. Assertion
  of THERMTRIP# (Thermal Trip) indicates the processor junction
  temperature has reached a level beyond where permanent silicon
  damage may occur.
}

Unless Intel has no clue, 82.2 (or 91, depending on the CPU revision ) °C is considered CATASTROPHIC COOLING FAILURE which may permanently damage the CPU.

Let me draw an analogy: do you think running a GPU at 110 °C is wise just because it's critical temp is 130 °C?

Nobody does that and lives happily ever after. Mind that bad guy on the balcony - and his two friends behind the sheriff's office as well ^^

Don't you run your GPUs at a temperatire radically lower than its TMAX?
Posts have been made here by guys who felt lucky and tried running their GPUs close to TMAX - they either RMA'd their GPUs or buried them in wooden boxes. Search them out if you so please.

Trying to keep everyone (and their hardware) safe,
Jake

(1) Yes, TC. Intel is using TCASE, not TJUNCTION here!

Is the manufacturer's specification wrong as well?
http://download.intel.com/design/processor/datashts/31559205.pdf

If he has the 105 W TDP version, 62.2 celsius it is.
If it's a later revision with 95 W TDP, the max temp is 71 °C
Being no psychic I can't know which version of q6600 he has. OP doesn't sound like a power user as well, so I used the safer of the two values.

I'm aware that a lot of folks perceive the q6600 as an overclock beast but I'm just supplying hard, technical data.
You overspec your CPU and all bets are off.

I changed my original post a bit, so as not to scare the living crap out of Soraka ^^

You need to hold your horses there, cowboy. You're galloping head-over-heels into town while a black-hatted, shotgun-toting bad guy is camping on the saloon's balcony.
You need to do some reading first, get a grip on what's what here in the bitcoin corral ^^


MANY OTHERWISE REPUTABLE SOURCES MISINTERPRETED INTEL'S SPECS ON THE Q6000 CPU FAMILY.
Your Q6600 might be ready to go belly up if you're actually keeping it at 70 CELSIUS.
Maximum operating temp for this CPU is 60.3 to 62.2 °C ⁽¹⁾

I MISINTERPRETED THAT SAME SPEC AS WELL.
YOU'RE OK WITH THAT CPU TEMP SORAKA, EXCEPT...
Do you use this CPU for bitcoin mining? CPU bitcoin mining has not been a viable option for a very long time now.

While your 250 GTS is in the clear (maximum temp for this card is 105 °C ⁽²⁾), there is a snowball chance in hell you'll make ANY money with this card.
Its bitcoin mining performance is just abyssal - a 150 Watt card averaging 35 MHash/s is laughing stock.

You're wasting far more resources on power than you can earn with your mining. Not to mention you seem to be killing your machine in the process.

I don't mean to put you off but in order to actually make any kind of profit mining bitcoin these days, you need to select your hardware carefully.
Damn, with current bitcoin proces, even GPU mining seems to be on its last leg...

Make sure to visit this site to compare various devices:  
   https://en.bitcoin.it/wiki/Mining_hardware_comparison

A quick glance will tell you that a single Radeon HD6950 card is EIGHT times as energy efficient as your 250 GTS.
A very inexpensive HD6770 with a power draw similar to your GPU should be capable of 200 MHash/s easily.

Put in some time, browse the forums, do the research, and for Chrissakes please do something about your CPU temp, will you?

Feel free to ask further questions, I'll respond when I'm able to.
Jake


References:
(1)
   http://HTTP://DOWNLOAD.INTEL.COM/DESIGN/PROCESSOR/DATASHTS/31559205.PDF
   http://www.cpu-world.com/CPUs/Core_2/Intel-Core%202%20Quad%20Q6600%20HH80562PH0568M%20%28BX80562Q6600%29.html
   http://www.hardwaresecrets.com/article/143/5

(2) http://www.nvidia.com/object/product_geforce_gts_250_us.html

EDIT: UPPERCASE

I pretty much agree with Technomage and BWagner.
I'm not ok with such a small and obscure link at the very bottom of the page, not by a long shot.

EDIT/CLARIFICATION: I voted Yes - I have no doubt that archive.org deserves our support, we just need to make sure a minor webpage update is bundled in with the donation ^^