Buying another 5850 for crossfireX, want advice.

[aqrulesms]

Hello,

I currently have a converted gaming rig that I am currently using for mining. It is currently running a 5850 at 300 mh/s at stock speed without OC, as I want to make sure my card has a fair longevity.

I am deciding whether or not to add another 5850 to this rig. The most concern I have is for the slowly increasing difficulty rate and was wondering if I could make back my $150 on this to later increase on my mining endeavors.

At the moment HD 5850s cost $150 each, as you may know. In total I am simply wondering that with the combined power of 600 mh/s, can I make back my money fast enough?

Power is not a concern, and it costs about 3 cents per kilowatt, totaling at 6 cents due to fuel cost.

Thanks for your opinions and advice. 

[Vanderbleek]

http://allchains.info/calc.html

Should answer your questions. If everything stays the same, your rig would make up the deficit in ~70 days. That seems about normal, it's usually around a 3 month repayment time for hardware, or so it seems.

[aqrulesms]

Thank you very much. I'll go along with my mining plan.

Will most likely just sell my PS3(which I no longer use) for this operation.

[Vanderbleek]

You can mine Litecoins on a PS3 -- I think Pooler wrote a SCrypt miner that runs on the Cell architecture.

[aqrulesms]

Hmm that might be good, but the problem is my PS3 is not jailbroken, and I have a very small budget as to my mining.

I'm thinking about just mining single with one 5850, selling my PS3 and then using the combined cash to get a 5970 + 5850 CrossfireX configuration.

Are the two even compatible? I've seen pics of people running them crossfire but I'm not too sure, and it's not officially supported by Ati.

[Vanderbleek]

You can run them in the same computer, but--

Two cards do not need to be crossfired to operate in the same motherboard, and many miners do not run their cards in xfire.

You could xfire them (the 5970 is two 5870s, and you can xfire any 58xx cards together) but you may actually see a performance decrease, since the 5970 will downclock to match the 5850.

[aqrulesms]

You can run them in the same computer, but--

Two cards do not need to be crossfired to operate in the same motherboard, and many miners do not run their cards in xfire.

You could xfire them (the 5970 is two 5870s, and you can xfire any 58xx cards together) but you may actually see a performance decrease, since the 5970 will downclock to match the 5850.

So it would be the most economical to purchase another 5850? A 5870 will also downclock to match the 5850 also, correct?

[DeathAndTaxes]

What he is saying is there is no reason or need to cross fire.  Leave the cards "uncrossfired" and you can use and two cards you like.  I wouldn't mix 5000 series and 6000 series cards if you can avoid it.  Each generation has optimal settings and trying to get settings optimal across multiple generations will be a pain in the ass.

TL/DR version:
I would get a 5870 over 5850.  Just don't crossfire.  Some people report no problems enabling crossfire but it doesn't provide any benefit so keep it simple.

[aqrulesms]

What he is saying is there is no reason or need to cross fire.  Leave the cards "uncrossfired" and you can use and two cards you like.  I wouldn't mix 5000 series and 6000 series cards if you can avoid it.  Each generation has optimal settings and trying to get settings optimal across multiple generations will be a pain in the ass.

TL/DR version:
I would get a 5870 over 5850.  Just don't crossfire.  Some people report no problems enabling crossfire but it doesn't provide any benefit so keep it simple.

Oh I never realized that you did not have to crossfire in a multi card configuration. Thanks for clearing that up! 

[Vbs]

I currently have a converted gaming rig that I am currently using for mining. It is currently running a 5850 at 300 mh/s at stock speed without OC, as I want to make sure my card has a fair longevity.

Here's a good starting point: I have two Sapphire 5850's@400MH/s each.They are running on 12.1 drivers with SDK 2.5 from the 11.11 drivers (SDK 2.5.793.1). I'm using cgminer with phatk kernel, vectors 2 and worksize 256; the cards are clocked at 970MHz core and 150MHz mems. I have auto-temp set at 70ºC (for "longevity"), the fan usually goes between 54-58% to achieve that.

[aqrulesms]

I currently have a converted gaming rig that I am currently using for mining. It is currently running a 5850 at 300 mh/s at stock speed without OC, as I want to make sure my card has a fair longevity.

Here's a good starting point: I have two Sapphire 5850's@400MH/s each.They are running on 12.1 drivers with SDK 2.5 from the 11.11 drivers (SDK 2.5.793.1). I'm using cgminer with phatk kernel, vectors 2 and worksize 256; the cards are clocked at 970MHz core and 150MHz mems. I have auto-temp set at 70ºC (for "longevity"), the fan usually goes between 54-58% to achieve that.

Despite that, the card does draw more power, and would lead to accelerated electromigration. The connections within the chip themselves would wear out and become "thin".

How long have you ran your cards at those configurations?

[grue]

I currently have a converted gaming rig that I am currently using for mining. It is currently running a 5850 at 300 mh/s at stock speed without OC, as I want to make sure my card has a fair longevity.

Here's a good starting point: I have two Sapphire 5850's@400MH/s each.They are running on 12.1 drivers with SDK 2.5 from the 11.11 drivers (SDK 2.5.793.1). I'm using cgminer with phatk kernel, vectors 2 and worksize 256; the cards are clocked at 970MHz core and 150MHz mems. I have auto-temp set at 70ºC (for "longevity"), the fan usually goes between 54-58% to achieve that.

are you overvolting? I don't think it's possible to get 400 MH with stock voltage.

[Vbs]

Despite that, the card does draw more power, and would lead to accelerated electromigration. The connections within the chip themselves would wear out and become "thin".

How long have you ran your cards at those configurations?

Bought both 5850's as refurbs, and have been running only for 2 months. You might like to read through this thread for more info on this http://bitcointalk.org/index.php?topic=48222.0

[Vbs]

I currently have a converted gaming rig that I am currently using for mining. It is currently running a 5850 at 300 mh/s at stock speed without OC, as I want to make sure my card has a fair longevity.

Here's a good starting point: I have two Sapphire 5850's@400MH/s each.They are running on 12.1 drivers with SDK 2.5 from the 11.11 drivers (SDK 2.5.793.1). I'm using cgminer with phatk kernel, vectors 2 and worksize 256; the cards are clocked at 970MHz core and 150MHz mems. I have auto-temp set at 70ºC (for "longevity"), the fan usually goes between 54-58% to achieve that.

are you overvolting? I don't think it's possible to get 400 MH with stock voltage.

Nope, stock voltage.

[Chomp]

I currently have a converted gaming rig that I am currently using for mining. It is currently running a 5850 at 300 mh/s at stock speed without OC, as I want to make sure my card has a fair longevity.

Here's a good starting point: I have two Sapphire 5850's@400MH/s each.They are running on 12.1 drivers with SDK 2.5 from the 11.11 drivers (SDK 2.5.793.1). I'm using cgminer with phatk kernel, vectors 2 and worksize 256; the cards are clocked at 970MHz core and 150MHz mems. I have auto-temp set at 70ºC (for "longevity"), the fan usually goes between 54-58% to achieve that.

are you overvolting? I don't think it's possible to get 400 MH with stock voltage.

Nope, stock voltage.

with 12.1/SDK 2.5 my sapphire 5850 gets 395MH/s
930 core 180 mem 1.088v
fan 50% 60c

[juhakall]

Realistically, I can't run my 5850 crossfire setup at over 800MHz core clocks, without creating a loud hurricane in my home. The upper card in my setup is a Vertex 3D 5850, and the bottom card is a reference model 5850. They are 2-slot cards, so there's an empty space of one slot between them. I run them at 150MHz memory clock and 777MHz Core clock, and they are still pretty loud @ 80C. The reference card is undervolted to just 1.012V. I'm getting 310MH/s from both cards, which is a little low. If loudness is of any concern, you can't really hope to overclock your cards in a crossfire setup inside a normal computer case, unless you have some serious cooling. You might even have to resort to underclocking, or redefining what "loud" means for you.

EDIT: I'm running SDK 2.1 with Catalyst 12.1.

[Fiyasko]

Hmm that might be good, but the problem is my PS3 is not jailbroken, and I have a very small budget as to my mining.

I'm thinking about just mining single with one 5850, selling my PS3 and then using the combined cash to get a 5970 + 5850 CrossfireX configuration.

Are the two even compatible? I've seen pics of people running them crossfire but I'm not too sure, and it's not officially supported by Ati.

Im sorry but i have to state that i laughed when i read "jail broken" I know im being an asshole for posting this but i couldnt resist.

Heres a picture about you quandery into comatability to help "de douche" myself

[aqrulesms]

PS3s cannot run unsigned code. It leads me to the conclusion that the mining script only works for jailbroken PS3s.

Is that correct?

[aqrulesms]

I currently have a converted gaming rig that I am currently using for mining. It is currently running a 5850 at 300 mh/s at stock speed without OC, as I want to make sure my card has a fair longevity.

Here's a good starting point: I have two Sapphire 5850's@400MH/s each.They are running on 12.1 drivers with SDK 2.5 from the 11.11 drivers (SDK 2.5.793.1). I'm using cgminer with phatk kernel, vectors 2 and worksize 256; the cards are clocked at 970MHz core and 150MHz mems. I have auto-temp set at 70ºC (for "longevity"), the fan usually goes between 54-58% to achieve that.

are you overvolting? I don't think it's possible to get 400 MH with stock voltage.

Nope, stock voltage.

with 12.1/SDK 2.5 my sapphire 5850 gets 395MH/s
930 core 180 mem 1.088v
fan 50% 60c

What OC tool are you using?

[Vbs]

What OC tool are you using?

cgminer takes care of controlling the o/c and fan automatically! https://bitcointalk.org/index.php?topic=28402.0

A good starting point for you to try:
cgminer -k phatk -v 2 -w 256 -I 9 --temp-target 70 --auto-gpu --auto-fan --gpu-engine 725-950 --gpu-memclock 150 --gpu-fan 55-85 -o http://pool:port -u worker_name -p worker_pass

For the settings above, I would suggest you use SDK 2.4/2.5 (my personal favorite is the 2.5 SDK runtime that comes with the 11.11 driver). You can also save the settings in a JSON config file.