Just built a system with 4 of these cards with a sempron 140 yesterday, built in a HAF-X case with a 1000w 80PLUS Gold OCZ PSU.

Modified the voltage of each card to 1.0v voltage via using RBE to edit existing bios, the 4 cards are running 860/280 across the board (for now, still stability testing, stable for over 24 hours atleast). Fan speed set to 60% across the board.. room temp of 26'c, hottest card about 78'c, coolest card about 50'c. Power draw measured from wall: 480w.

Seems like I could have built this system with a 600w PSU after the undervolting. System total is about 1060mhash/sec (~265 per card using poclbm phatk), build cost was about $900 before tax as I got each card for $103, but if I knew the power draw was going to be this low I could have opted for a PSU that wasn't $150.

With this version over regular poclbm, my HD5830s get about 10mhash/sec more per card.

But there's just one problem, I keep getting long polling exceptions working off BTCGuild USWest such as:


Sometimes it will reconnect and recover, sometimes it doesn't bother and just sits there idle, until I notice that the miner has been disconnected for a few hours. This doesn't happen with regular poclbm.

1. Yes, it was stupid. I have several different passwords, the password I used for mybitcoin and mtgox was my "junk" password, while I was dabbling with mtgox. Anything financial or important has it's own unique password, but as I do not use a password manager I won't create a unique PW for a site that I will rarely, if ever use again. I never thought to change it after bitcoin became valuable to me.

2. My bitcoins left my account less than 24 hours after this notice went out. I went to bed on Sunday without receiving the email that something was wrong with mtgox during that day, I woke up Monday, went to work in a rush without checking my email, came home and saw the email, checked mybitcoin, and my coins were gone.

3. See above.


I don't live on the forums, nor do I regularly look at news sites, nor do I have a smartphone with mobile broadband to check email with. I do not have a TV so I would not have seen it on news. The only hint I had was that email, and by the time I actually got it, the account was already long compromised. Not everyone who is an advocate of bitcoin actually keeps up with the news on it. It really is boring to me because it will take a long time for bitcoin to become anything more than it's current effective status of "encrypted/untraceable USD funds", so I only check up on this stuff once every couple weeks.

Is it my fault? Ofcourse, in multiple ways it is. The password thing is one obvious one. The other is relying on a service to maintain it's security in exchange of my FEE PAYMENTS for them to uphold their service. The fee mtgox charges on exchanges is obviously to pay the person operating the exchange, in a way they are responsible to maintain their service's security. Since they didn't uphold proper service, scammers have made way with several hundred thousand dollars from the common users, regardless of the method achieved. It's like saying Sony isn't to blame for several people's credit cards being compromised and charged through the roof, and instead is the user's problem for not cancelling their credit card the very instant the news broke ice. Sony didn't uphold proper service, and caused the problem to happen regardless. Lots of people simply didn't even get the news of Sony being compromised, or thought it didn't effect them because they haven't used sony's services for many years, or forgot the one time they lent the nephew the credit card to buy some DLC or some crap when he was staying the night.

Uhh.. not everyone that uses bitcoin tolls over the forums every single day. I visit this forum once  every 2 weeks or so I saw no warning to respond to within 24hrs, I came home from work that day and my shit was gone, that was my "warning".

Having identical passwords is one thing, but do not claim everybody follows the same routine you do. I don't daytrade bitcoin, nor do I use bitcoin rss feeds, or anything like that. I leave my 1.2ghash/s mining and go do other things, and check my bitcoin count every couple weeks.

Lost 62 BTC to the same address today.

I'd probably be a bit more angry if I wasn't well in the green, and is nothing in comparison to those with 1000+ BTC.

More of an expensive lesson for my own stupidity - all my financial accounts have separate passwords, yet I never took mybitcoin serious enough to give it a separate password.

Safe is more or less below 85'c for 24/7 mining.

Using MSI Afterburner you can unlock frequencies fully by editing the cfg file in the afterburner folder (should find this on google quick), so it will let you set your core clocks anywhere up to stupidly high amounts (ie: 1.3ghz). Pretty much any 40nm ATI card can expect atleast 900mhz core.

In theory, people who have lesser efficiency mining rigs would simply stop mining, which would then decrease difficulty.

There are alot of people who will eventually be sick of seeing less than 1 BTC per day from slush's pool on their nvidia cards and will drop off.

If you reduce the memory too much, it can cause graphics errors. My HD5870 cannot go under 425mhz memory without getting graphical glitches like you've mentioned. Sometimes after you set the 300mhz clock, then return the card to stock the glitches won't go away until you reboot as well.

Using SDK 2.2 instead of 2.3 or 2.4, I still get 2 cores put to 100% load using a HD 5870 and HD 5670 on Win7.

For the meanwhile anyone with this problem can set CPU affinity to only 1 (same for all) core for all poclbm processes so only one core is fully loaded, that way less electricity is used and less heat is made until a proper solution arises.. it doesn't seem to effect hash rate at all.

The best bang for the buck mining is the HD 5870.

A few places around here sell it for about $185-$200 CAD new, and it will have 43% better performance per clock than a HD 5830 because it has 43% more shader units (1600 vs 1120 on the 5830).

At only 900mhz it puts out about 330,000 khash/s, I've also seen 390,000 khash/s at 1030mhz (although with my reference cooler, I can only keep it at about 930mhz unless I want a hairdryer in my room). This is all using SDK 2.3 on Windows with the 11.2 driver. I tried SDK 2.1 as well as older drivers and found no significant difference at all (less than ~5m increase/decrease). I also didn't notice anything significant upgrading to SDK 2.4.

I wouldn't agree that the 6870 is a better miner than the 5850 either. The 58xx and 68xx/69xx series all top out at roughly the same core frequencies, most will cap out anywhere from 950-1000mhz for mining. HD 6870 is already 900mhz and doesn't have much headroom, HD 5850 is 775mhz and has much more headroom for overclocking. That all being said, HD 5850 already performs better for mining when both are at stock frequency.

My HD 5850 at ~920mhz sees roughly 300,000 khash/s. Comparing my HD 6850 at the same frequency of 920mhz.. it only sees about 215,000 khash/s.

MSI Afterburner, look into enabling unofficial overclocking (google).

Though my card allows up to 1300mhz in CCC without doing this.

Make sure -v -w 128 is on your command line.

My HD 6850 gets about 230-235Mhash/s at 1ghz with "-v -f 5 -w 128" set, your 6870 is a bit low considering it has 160 more shaders, I would expect it to top out closer to 250-260Mhash/s at 1ghz.

I don't see any performance problems with ATI Stream SDK 2.3 on Win7 with m0mchil's python miner, I don't see why so many people instantly suggest to downgrade.

My HD 5870 gets about 355-360 mhash/s at 940mhz with -v -f 5 -w 128, and my HD 6850 gets about 230-235 mhash/s at 1ghz with the same switches.

On my 5870 @ 940mhz I run the fan at about 50% (~2350rpm), the temp flatlines at a constant 81-82'c at this speed. Another thing is that the stability of the core overclock is a bit misleading with mining, my card at stock voltage only runs stable at 910mhz with games + mining at the same time (915mhz = crash), but has mined for a week at 940mhz without a single hickup. My HD 6850 gets a similar result and is stable running at a ~20-30mhz higher core speed for mining than games. I just created seperate profiles in MSI Afterburner to quickly switch the core between 910 and 940mhz depending on what I'm doing, as that little 30mhz boost increases the speed by about 10m hash/s.

You could probably overvolt and get into the 380-400 range with a single HD 5870 if you had one with a nice cooler, but the reference coolers are hot/loud enough on stock voltage as-is even with great case cooling and room temps.

Sorry, I should have mentioned that I'm using Windows 7 64bit.

So I'm using m0mchil's bitcoin miner and I've had it working fine on the HD6850 @ 220mhash/s, and I've since added a second card in - a HD4850 I had laying around.

I'm having problems getting this one detected as an OpenCL capable device, I've removed and reinstalled ATI Stream SDK 2.3 as well as reinstalled video drivers + opencl driver, didn't make any difference.

GPU Caps Viewer doesn't list it as an OpenCL capable device either. Anyone know what could be preventing this from working right? It seems the 4xxx series doesn't support OpenCL properly but there are others in the thread claiming to be using 4800 series cards.