5970 or 6990??

[goozman96]

I started mining several days ago but unfortunately I have an NVIDIA BFG GeForce GTX 260 which averages me around 45 Mhash/s. I was looking into some ATI cards since they have much higher outputs. But I'm kind of confused. According to this chart, a 5970 could get me anywhere from 530 to 802. How is this possible? Are there different varieties of each card or what? And also a 6990 can get me anywhere from 670 to 835. How can I know what speeds I will get with each card with my current set up?

I should probably state that I use GUIMiner and I have Windows 7 Ultimate SP1 64bit. Any additional specs (if needed) can be found here under the System Specs tab.

I actually live in an apartment while I am going to college and my rent includes electricity, so its of no concern to me.

Thanks in advance!

[smoki]

A lot of factors can affect a card's hashing speed:
- gpu clock speed: this one is a no-brainer - hashrate scales almost perfectly linearly with gpu frequency
- video memory speed: this one is a bit trickier - most cards actually improve performance if you lower the memory speed. The sweet-spot can be anywhere between 160 and 400 MHz for 5xxx and 6xxx series cards. The impact on hashing speed isn't nearly as big as with gpu frequency, but gains up to 5% or so can be achieved
- APP SDK version: 2.1 is supposed to be the best for 5xxx series cards, giving ~10% higher performance than 2.4. Versions 2.2 and 2.3 are not recommended for several reasons (low performance and high cpu utilization). 6xxx series is not supported in 2.1 though.
- Catalyst version: from what I've read results seem to be all over the place, so I can't really recommend which version to use. I'm sticking with 11.5 for my combo of 5870 and 6870 cards.
- OS: again, different people report differently about whether Windows or Linux is faster, same for 64-bit vs. 32-bit
- miner used: phoenix's phatk kernel seems to be the fastest for most users, at least under Windows. Under linux, again, different users have different results with various miners. In my case it's pretty much a wash between phoenix (phatk) and poclbm under linux.

As for card choice... a 5970 is more power efficient and has better performance at a given gpu frequency. You can also use 2.1 APP SDK with it. It should also be cheaper to buy. It's probably just about impossible to get either new or used. It will also be harder to sell when you stop mining, or, if you keep it for gaming, will be a good deal slower than the 6990.

[Basiley]

depend price.
also, not thats 6990 pack lot more heat/consumed power. in bigger scale than boost from increased shaders number.
generally im thing 6990 is OP and too big/fat/hot for 40nm waffer/transistors.
so, if you can find 5970 its okay enough, IMO.

[Jack of Diamonds]

I don't notice any difference between Phoenix and POCLBM using a 6990.

In fact Phoenix just makes it run too hot without noticeable speed benefits (using sdk 2.4).
Also core 0 is always about 5% slower than core 1 even though both have the same exact flags.

[goozman96]

I don't notice any difference between Phoenix and POCLBM using a 6990.

In fact Phoenix just makes it run too hot without noticeable speed benefits (using sdk 2.4).
Also core 0 is always about 5% slower than core 1 even though both have the same exact flags.

What speeds do you get?

[Jack of Diamonds]

I don't notice any difference between Phoenix and POCLBM using a 6990.

In fact Phoenix just makes it run too hot without noticeable speed benefits (using sdk 2.4).
Also core 0 is always about 5% slower than core 1 even though both have the same exact flags.

What speeds do you get?

351mhash/s on core 1, 339-342mhash/s on core 0. Also core 0 temperature is 92c constant, core 1 is 78-81.

Doesn't matter what flags I use or none at all; Core 0 always runs hotter and slower.

Nothing else is being used or run the card.

[goozman96]

So what would you have to do to get it to the theoretically possible 800+?
I assume it's not overclocked or anything, right?

[Jack of Diamonds]

You have to raise the voltage and OC to 950-990mhz which I'm not going to do, and wouldn't advise anyone else to do so either.
The card is already pushed to it's limits running practically two full 6970's if you switch to the normal OC mode (830 -> 880mhz plus increased memory clock)

I'd never run the cores at nearly 1ghz and over 100 celsius 24/7. Even with watercooling I think it's unsafe and stupid with a $800 card.

[goozman96]

Ah, I see. I think my graphics card already came OverClocked out of the box.
This is it: http://www.amazon.com/BFG-BFGEGTX260MC896OCE-GeForce-MAXCORE-Graphics/dp/B001G0MSMG

So there's not much I can do to increase my speeds with my current card?

[newguy05]

Ah, I see. I think my graphics card already came OverClocked out of the box.
This is it: http://www.amazon.com/BFG-BFGEGTX260MC896OCE-GeForce-MAXCORE-Graphics/dp/B001G0MSMG

So there's not much I can do to increase my speeds with my current card?

why you running nvidia? it's a waste of money and time.

[goozman96]

I built my current rig about 3 years ago; way before I had a clue what BitCoin was - cuz it didn't exist yet!

[jgraham]

I don't notice any difference between Phoenix and POCLBM using a 6990.

In fact Phoenix just makes it run too hot without noticeable speed benefits (using sdk 2.4).
Also core 0 is always about 5% slower than core 1 even though both have the same exact flags.

I think it stands to reason that if the choice of software is causing the card to run hotter then it's likely getting your card to do more work.   The MH/s in POCLBM might just be measuring/displalying the hashrate while hashing so without all the network overhead.

I'd try running a benchmark by looking at the number of shares done by each core over say a couple of days.

I'm doing this exact thing between phoenix/poclbm and phoenix/phatk+mod