Bitcoins

[Andy]

OK, I've got it running on Deepbit using that GUI. I'm getting just under 300MH/s with no flags. I tried -v which slowed it down to about 260MH/s.
Anyway I can improve this? Using an XFX 6950.

Found this on a forum, give it a go: -v -f30 -w128

 

[El Xando]

I added "-v -f30 -w128" to the flags as https://en.bitcoin.it/wiki/Mining_hardware_comparison advises, and now I'm getting around 315MH/s. Any other advice?

EDIT: Haha cheers Andy, didn't see that post before I posted this

 

[El Diablo]

Yeah thanks, I'm using the same card and was able to go from about 295 to 310-315 now.

 

[El Xando]

I tried running it with my seconday 5450 - got 15MH/s so stopped it.
What temperature has this got your GPU at El Diablo? I'm up to 90C.

 

[El Diablo]

Yes mine is around there too and actually crashing my PC =\.

 

[Andy]

Change your fan speeds...

 

[El Xando]

Yes mine is around there too and actually crashing my PC =\.

Ah... mine hasn't done that yet. I think you can use flags to turn it down and maybe not use all your GPU?

Any other advice x3?

---------- Post added at 05:40 PM ---------- Previous post was at 05:38 PM ----------

Change your fan speeds...

That sounds like a plan, mine's only at 40% fan speed with 100% activity...

 

[x3sphere]

I use the same flags, and get ~370 mhash/s on my 6970. Only crash I had was when I tried to play YouTube vids at the same time, which is a driver issue. You need to disable hardware acceleration in flash. as for improving the speed I think around 310 mhash/s is the max for a 6950 without OC'ing.

 

[Andy]

I get 280Mhs on my 5830, looks like I'm winning bros

 

[El Diablo]

Yea the first time I crashed was trying to watch youtube, then I crashed again from trying to start GPUz while bitcoin was running. Not sure if it was overheating but the card definitely was getting there lol.

 

[x3sphere]

Yeah it puts a lot of stress on your GPU. I keep my fan speed at 50%, hovers around 68-70C.

 

[El Xando]

Yeah it puts a lot of stress on your GPU. I keep my fan speed at 50%, hovers around 68-70C.

What pool and program are you using out of interest?
I just put my fan to 50% and that's only got it to around 75C, sounds like either you have better case cooling or 6970s run cooler (or a bit of both )

 

[x3sphere]

What pool and program are you using out of interest?
I just put my fan to 50% and that's only got it to around 80C, sounds like either you have better case cooling or 6970s run cooler (or a bit of both )

GUI Miner. I'm using the reddit pool at https://mtred.com/

I have an external fan blowing air into my computer so that's probably helping quite a bit with the temps.

 

[El Diablo]

I tried running it on my laptop for fun to see if it would be worth it to run that too...getting 12MH/s with it compared to 310 from my desktop lol...so much for that.

I'm also running an external fan blowing into my computer with the side case off right now with the GPU fan set to 50%. Temp seems to have leveled out at 73C now and doesn't seem to be going any higher.

All in all I think it's a lot of trouble for the amount of money you could get from it lol, but I guess if I go out or go to work or just can't play games at the moment, some free money for running my graphics card never hurts.

---------- Post added at 01:11 PM ---------- Previous post was at 01:10 PM ----------

Sorry for double post, but I also thought I saw that someone said with the 6970 bios on the 6950 they were able to get around 370+MH/s. Not sure how safe it really is to run that though since I remember seeing people talking about bricking their cards a while ago flashing the 50s to 70s.

 

[MenaceInc]

Wouldn't trust the money made from this at all. Aside from potential tax issues, it seems too risqu

 

[Andy]

Wouldn't trust the money made from this at all. Aside from potential tax issues, it seems too risqu

 

[El Diablo]

What exactly is different that makes the ATI cards so much better at this than nvidia? I see the lowest 6990 on that list is doing about 670MH/s whereas the GTX 580/590 seem to do 150-190. I know the 6990 is a better card but the 580 is better than mine for gaming and everything else, what determines that I get about twice the performance in this as that card?

 

[Andy]

What exactly is different that makes the ATI cards so much better at this than nvidia? I see the lowest 6990 on that list is doing about 670MH/s whereas the GTX 580/590 seem to do 150-190. I know the 6990 is a better card but the 580 is better than mine for gaming and everything else, what determines that I get about twice the performance in this as that card?

It's something to do with the AMD architecture being more efficient for the tasks BTC mining has.

 

[x3sphere]

I don't see any risk in doing this. There's nothing illegal about buying a Bitcoin. As for taxes, just make sure to report the income. Here in the US you only have to report if you make >$600 from one source. Only thing is, there's so many people jumping on the bandwagon so I don't know how profitable it will remain. Oh well, happy with the $90 or so I've made thus far for doing nothing.

What exactly is different that makes the ATI cards so much better at this than nvidia? I see the lowest 6990 on that list is doing about 670MH/s whereas the GTX 580/590 seem to do 150-190. I know the 6990 is a better card but the 580 is better than mine for gaming and everything else, what determines that I get about twice the performance in this as that card?

It is down to significant architectural differences, basically more (but less complex) shaders give AMD the advantage. From the Bitcoin wiki:

Firstly, AMD designs GPUs with many simple ALUs/shaders (VLIW design) that run at a relatively low frequency clock (typically 1120-3200 ALUs at 625-900 MHz), whereas Nvidia's microarchitecture consists of fewer more complex ALUs and tries to compensate with a higher shader clock (typically 448-1024 ALUs at 1150-1544 MHz). Because of this VLIW vs. non-VLIW difference, Nvidia uses up more square millimeters of die space per ALU, hence can pack fewer of them per chip, and they hit the frequency wall sooner than AMD which prevents them from increasing the clock high enough to match or surpass AMD's performance. This translates to a raw ALU performance advantage for AMD:
AMD Radeon HD 6990: 3072 ALUs x 830 MHz = 2550 billion 32-bit instruction per second
Nvidia GTX 590: 1024 ALUs x 1214 MHz = 1243 billion 32-bit instruction per second
This approximate 2x-3x performance difference exists across the entire range of AMD and Nvidia GPUs. It is noticeably visible in all ALU-bound GPGPU workloads such as Bitcoin, password bruteforcers, etc.

Secondly, another difference favoring Bitcoin mining on AMD GPUs instead of Nvidia's is that the mining algorithm is based on SHA-256, which makes heavy use of the 32-bit integer right rotate operation. This operation can be implemented as a single hardware instruction on AMD GPUs, but requires three separate hardware instructions to be emulated on Nvidia GPUs (2 shifts + 1 add). This alone gives AMD another 1.7x performance advantage (~1900 instructions instead of ~3250 to execute the SHA-256 compression function).

 

[El Diablo]

Hm...I just noticed scrolling down the hardware list that you can use it on a ps3 with CFW. It only looks like about 20MH/s but maybe now I have incentive to stop being lazy and put a CFW on my ps3 with a broken bluray drive to let this run on it...