Topic: Record hashrate for a 5850? (me, showing off) - page 2. (Read 15271 times)

way to necro and what clock was you running it @ for 95c on a after market cooler?

with the new Version of TRIXX it is possible to OC more than one card

maybe it is thanks to the mail I send them to do a version for multi GPU support 

I know practically nothing about overclocking the 5870s although I did see a screenshot of someone using Windows who had their 5870 up to 1.35V and 1135 MHz so they were able to break my current 1.3V barrier.  Not knowing makes it a gamble, particularly with Linux as Sapphire don't seem to be aware that Linux exists.

If you can unlock the shaders then a 6950 looks like a good plan.  Unlocked it might be competition for a 5870 (the 5870s are incredible miners).  I still can't say anything about your ability to overclock or overvolt but if you're using Windows then the risk is small.

Also, if you are looking for energy efficiency then 430 MH/s might be a bit much for an unlocked 6950.  I see from the linked page that this is achieved by taking the card to 1.275V which is a pretty serious overvolt.  Remember that power increases quadratically with voltage and linearly with clock rate so a 20% overvolt on both should give you about a 73% power consumption increase (of the gpu - not necessarily the whole card).

hhmmm ... thanks for the warnings ! sooo .... you think it's safer to buy 5870 instead of 5850 or are they both suffering from same gambling problem
yup trixx is my favorite way for I just get along better with it ... MSI Afterburner got a littlebit on my tits ... so I hit the button and rid myself of it !

ok ... I know from a buddy of mine that 6950 with 2 gb ram can be unlocked shaderwise for sure ... since that's going at about the same price as a 5870 where I am, would that be a safer bet ? I read here https://en.bitcoin.it/wiki/Mining_hardware_comparison that 6950 can also exceed 430 Mhas/s and that'll be more energy efficient as my 5830 at 330 despite double the price ... and only 30% or so gain in performance . what do you think ?

Private communication with the original builders of my rig, BlightyCoin, revealed that some Sapphire 5850 Xtremes can be overvolted to 1.3V on Linux with Catalyst 11.6 and AMDOverdriveCtrl but some will not go beyond 1.0875V.  Given that my cards do go beyond and their cards do not and because I believe I ordered one of the first rigs they assembled, I think that newer BIOSes will limit your overclocking potential in Linux.  I'd be very worried about overclocking/overvolting limits in your position as they were the greatest obstacle to configuring my rig.

If you are using Windows then you have Trixx but I hear there are a number of annoying limitations with this too so beware.

All I can advise is to read everything you can find on the subject, buying the card is almost certainly going to be a gamble but you can atleast get the odds in your favour.

Also, if you cannot overclock you can always undervolt instead so that the rig isn't completely useless but I guess this is little compensation.  My good card is undervolted by 0.1V and it still clocks 170MHz above stock so the untapped potential could be huge.

Best of luck!

hey gang ! I got 5830 here and am reaching 330s with sapphire Xtreme stk voltage and 1040  370 mems @ 78 C stable 24/7

Want to go buy 5850 or 5870 but am a bit scared due to not knowing whether I can OC them... So if I stk to sapphire Xtreme 5850 or saphire 5870 will I be ok ?

Thanks ! yup ... you were right pushing the envelope is my game Diablo you rule for your mods to phatk

Cheers,
Al

I'm sorry, I've been assuming that the 5xxx cards and 6xxx cards use a different size process.  A quick look online suggests they both use a 40nm process but I can't be sure.  What I do know is that the Sapphire HD5850 Xtreme cards are quite a bit shorter than the reference 5850s and are built more like the 6xxx family.

I appreciate that I've been extremely lucky with my cards.  Perhaps the manufacturer has a lot to do with it.  I do know that when running a GUI and with stock cooling the maximum stable clocks of the cards were around 900 MHz but I didn't do any testing after removing the GUI and replacing the coolers so I can't say which of these two had the most impact.  A card that only goes to 870 MHz even with good cooling, and doesn't accept even a small overvoltage, sounds like a very bad card to me.  I assume that if you undervolt the card you lose stability at 870 MHz.

Ohm's law is "Voltage = Current * Resistance" but there are two caveats to mention here.

1) Current is not Power.  Check out Joule's Law to see that both heat and power are proportional to the square of the current.
2) As temperature increases, resistance increases, so current will grow slower than linearly as voltage is increased.

I agree that the maximum stable clock seems to grow logarithmically as voltage is increased (and so voltage must be increased exponentially to increase maximum stable clock linearly).  However, just as 1 + x is a good approximation for exp(x) for x close to 0, small changes in voltage close to stock voltage will affect maximum clock rate approximately linearly.

Also, I'm fairly sure that increasing the clock rate increases the power consumption linearly.  Combining this with the above, if you increase both your voltage and core clock by 10% you should expect the power consumption (of the core) to increase by 33.1% (a cubic relationship).  I think some people choose to do this is because, for them, 10% more MH/s is actually more valuable than 33.1% more power + shorter card life.  I'm sure some people do it because they think it's profitable when it is not for them.  Some people do it because they are overclockers and are actually slightly more interested in configuring, pushing, and comparing cards than the bitcoins.  These people will invest in after-market coolers or water cooling (not profitable), do copious testing (more profitable to just get reasonable settings and let the card run), and will post what they learn online (not profitable as it increases the network hashrate).

I think you can still get the Sapphire HD5850 Xtremes (I think they were released even after some of the 6xxx family!)  They cost about 130 GBP each.  I can't vouch for their power in gaming but they certainly fare well with the 6xxx family for mining.  Indeed, I believe the 5970 is the fastest mining card (I'm fairly sure it's capable of 1GH/s underwater and I don't think the 6990 can do that) so the 5xxx family is doing something right.

Are you saying the Sapphire 5850 Xtreme model is built on a smaller process (nanometers) than the normal 5850's ?  Because the stock voltage you listed for it is the same as my original reference 5850.

It's crazy how it's totally luck of the draw with GPU chips.  I have two reference 5850s, one that still has the stock red blower heatsink on it and will do 400+ MH/s, and one with a crazy aftermarket heatsink on it that keeps it at 55c, RAMsinks, and air blowing over the ram and vrm's, and it won't go any over 870 MHz nor will it accept any overvolting whatsoever (instant lockup)


Also as to the extra voltage being linear or exponential, according to ohm's law it seems like it should be linear, but I have also read elsewhere that power increases with the square of the voltage added (maybe due to excess heat being lost through the transistors?), so I don't know which is correct.  What I do know however, is once you hit the ceiling clock with stock voltage and begin adding extra voltage to go higher, it quickly gets into diminishing returns and the extra voltage needed goes exponential.


Too bad they stopped making 5850's and 5870's, they really were powerful little cards even by today's standards!

I see what you're saying.  I don't want to mislead people into thinking that overclocking to the extreme is a good idea financially and I agree that many people would be interested primarily in profit given the tools (not all but most).  Maximising profit is far from easy but my feeling is that a mild undervolt is best in this regard (accounting for the high value of BTC compared to power costs for GPU miners and the cost/depreciation of the cards themselves).

I personally rather like using mining for benchmarking cards simply because it shows off the OpenCL power that the cards have.  In the long term I will want to use my cards for tasks such as Folding@Home, Mandelbrot fractal generation, Strong Go/Weiqi/Baduk engine, and am not interested in 3D acceleration, video acceleration, desktop effects, or GUI at all.  Mining is a good benchmark for the former because it is a test of low memory/bandwidth raw OpenCL processing which I can run without a GUI and supports a rather cool crypto currency.  Naturally, for Folding@Home high efficiency is most important and I'll get to that but for Mandelbrot and Go it's all about performance.

i only wanted to point out how inefficient overvolting is. i'm not sure about the actual increase in power given a voltage increase, but even if it was linear, your core clocks won't scale linear and neither will your hashrates. so if the consumption increases quadratic, you're looking at an even greater loss. i'm pretty sure if people could monitor consumption without much effort, this would be the benchmark everyone would go for. too bad you can't measure consumption without buying tools, so we're stuck with benchmarks of raw hashing power. this is insane, though. if you like benchmarking and comparing your results, go for something else than mining. go do some weird 3dmark benchmarking sessions with LN2 and quad-fire etc.

Alright, I'll say this one more time.

Running your cards at high voltages or temperatures for extended periods will likely cause the cards to die prematurely.  These records should be taken as a measure of potential and can be useful for comparison but for most circumstances will not be profitable for long periods (considering power costs, card depriciation, or both).

If you are concerned only with maximum profit then this thread is not for you (unless you have no power or hardware costs and limited time) but you might hope to reap the benefits of the work done here in the long run.

When my power meter finally arrives I'll be undervolting my cards and looking for high MH/J scores then.  I'll make a thread for this when I'm ready and perhaps you'll find it more useful but, just as here, it will be for research and NOT recommended for maximum profit.

I do not deny the diminishing returns of increasing voltage but I don't understand why increasing voltage will increase power consumption exponentially and perhaps you can explain why?

If you increase the voltage (assuming no change in electrical resistance of the cards circuitry) then the current will increase in proportion (Voltage = Current * Resistance) and therefore the power consumption will increase quadratically (Power = Voltage * Current), not exponentially!  In real life the increased current will increases the temperature of the circuitry and therefore the electrical resistance so the growth of power with respect to voltage will actually be a little slower than quadratic.  Increasing clock rate will increase power consumption approximately linearly as far as I understand so if you increase both voltage and clock rate by 10% you might draw around 23% more power.

I simply cannot see how voltage and power can have an exponential relationship.

No, I'm talking about a 5850, in particular a Sapphire HD5850 Xtreme.  This particular card is built with the 40nm process and looks like a 6950 but has the essential structure of a standard 5850.  It will go to 1030 MHz on stock voltage provided I keep it cool enough and will run happily at that speed for days at a time without freezing.  To get more than 1030 MHz I had to increase the voltage and the increase from stock (1.0875V) to 1.25V was sufficient to make 1110 semi-stable (it only lasted 3 hours).  Indeed, the card went to 1130 MHz but was not stable (lasted only 90 seconds).

I'm sure the low temperature (about 55*C) and lack of a GUI made a difference to my maximum stable overclock.  In particular, I can't tell you whether or not mouse movement would have crashed the card because there was no mouse to move.  I'm sure if I was mining in a GUI environment I'd have to drop 50 MHz off of my clock to get stability, and another 40 MHz if the GPU was over 70*C.

I posted on the 5870 thread rather than here because they were interested in maximum speed whereas here we were more interested at maximum speed at 1GHz core.

The more you add the quicker it adds up (exponentially)

So yes, at the levels shown in this thread, 0.2V increments will result in 20-30% bigger power draws

At 1.3V or above you are already crossing a negative threshold
(you will be paying more for electricity than you will earn from the extra few dozen mhash/s

But as long as people just want to see a 'big number' without caring how much electricity is required to produce it, go ahead..
Or the fact the VRM will die in a month.

well, around that, yes. maybe 30%.

are you sure increase for 0.2V give 50% more power consumption?


are you talking about a 5870?
I am on a 5850. I run it for 10min it was limit stable I touch the mouse => BSOD. But now I mine at 426MH/s with a 1040MHz clock stable.

Without changing the voltage it's hard to get a 5850 to 1GHz.  The most important factors seem to be system stability (don't drive a GUI and mine with the same card) and low temperature (certainly less than 60*C).

Just incase your inability to increase the voltage on your cards is a software issue, I'm able to change the voltage by using Catalyst 11.6 and AMDOverdriveCtrl (editing the .odrv profile for higher voltage, a GUI slider may not go beyond 1.0875V).  This is on Linux but I can't imagine it's harder on Windows.  No BIOS flashing or Trixx should be required.  Older versions of Catalyst will suffice if you only want to decrease your voltage.  I cannot make my voltage increase beyond 1.3V with this method.

Unfortunately not but that is a damn good hash rate but then 1055 MHz is a very high clock.  I feel that it should be possible to get more MH/s at that clock rate but is your card stable at that rate?  How long did you run the miner for?

I decided to overvolt my good 5850 from stock (1.0875V) to 1.25V and see what it could do.  It managed to hold 1110 MHz under load for 3 hours (finally dying when I got adventurous and tried to start mining on my other card) and managed 461.1 MH/s with very few stales.  I posted about this here.  You can get a screenshot here and I have pictures of my rig here.  Admittedly, I have the advantages of Linux without any GUI, very good aftermarket coolers, and lowish ambient temperatures where I am (peaking at 21*C in the middle of the day).

I was proud to have beaten the highest claimed 5870 record but it wasn't long until scifimike12 took his water cooled 5870s to an astonishing 501 MH/s (which ran for an hour before he turned it down).

Needless to say, I do not run at 461.1 MH/s all the time.  I'm not very concerned about the voltage or heat and I'm not convinced it's not profitable but there was simply far to much noise.  428 MH/s at stock volts and 50% fans is ok for now and I'm going to undervolt my cards and turn down the fans once my power meter finally arrives.

you guys don't actually get it. why would you want to invest like 50% more power consumption for a mere 30 mhash/s? is this a benchmark? try benchmarking actual mining efficiency.

you know what, i hate you but i shall persevere, once i cool those vrms ill be pushing more