Best bang for the buck GPU for mining LTC?

[Tomatocage]

Title says it all.  I got a few more free slots on my mobo.  Post your opinions!

[Greedi]

5850

[smoothie]

Title says it all.  I got a few more free slots on my mobo.  Post your opinions!

6950

[SaltySpitoon]

Title says it all.  I got a few more free slots on my mobo.  Post your opinions!

6950

I second this. 6950s are probably your best bet. Flash them to 6970s, get 500 Khash for $150 or less. That and, if/when ASICs come out, the GPU will still have resale value as its still viable for gayming.

[smoothie]

Title says it all.  I got a few more free slots on my mobo.  Post your opinions!

6950

I second this. 6950s are probably your best bet. Flash them to 6970s, get 500 Khash for $150 or less. That and, if/when ASICs come out, the GPU will still have resale value as its still viable for gayming.

Yup unlock the shaders and you're golden.

[DiCE1904]

Im also in need of figuring this one out. I'm torn between getting some 6950s or more 7970s

I emailed a rig builder about the question, and this is what I got back. I would appreciate some feedback from a big GPU miner on this

A stock 7970 has twice the performance available that the 6950 has.  Plus it uses less power.  I'm not wanting to do stock, I'm wanting to do the GHz edition AMD just put out which will have even more performance, and still use less power.   You are talking 4300 GFLOPs for the 7970, and 2253 GFLOPs for the 6950.  You are looking at about 200 extra watts of power comparing 7 7970s to 7 6950s, and 880 more watts comparing 3 7970s to 7 6950s.  I don't think there is a power supply made that can handle 7 6950s, and you will be getting close to the limit with 7 7970s, but that extra 200 watts could make or break you.

[tacotime]

Stock 7970 gets about 650-700 kh/s and will use an estimated 230 w of power (256 w from the wal at 90% efficiency).  I know this from personal experience.  A 6950 will pull roughly about 200 w (222 w at the wall; these are estimated, but mrtlt used 6950s when he mined and the power clocked in at roughly these amounts) and get 450 kh/s.

My 7950s also get 550 kh/s at 227w at the wall.

Okay:

7970: 2.64 kh/s/w
7950: 2.42 kh/s/w
6950: 2.02 kh/s/w

Thus the 7970 mines at 77% of the power of the 6950, with the 7950 tailing it.

Additionally the kernels totally suck balls right now for GCN, so this may improve over time.

[DiCE1904]

Stock 7970 gets about 650-700 kh/s and will use an estimated 230 w of power (256 w from the wal at 90% efficiency).  I know this from personal experience.  A 6950 will pull roughly about 200 w (222 w at the wall; these are estimated, but mrtlt used 6950s when he mined and the power clocked in at roughly these amounts) and get 450 kh/s.

My 7950s also get 550 kh/s at 227w at the wall.

Okay:

7970: 2.64 kh/s/w
7950: 2.42 kh/s/w
6950: 2.02 kh/s/w

Thus the 7970 mines at 77% of the power of the 6950, with the 7950 tailing it.

Additionally the kernels totally suck balls right now for GCN, so this may improve over time.

so knowing these rates tacotime would you go with 7 7970s or 7 7950s or 7 6950s?
Maybe it could comes down to the hash rate per dollar I guess? And you can always watercool these for an extra $100 each card to improve.

5858: $168 - 384Mh  2.28
6950: $200 - 450Mh  2.25
7950: $320 - 550Mh  0.58
7970: $400 - 600Mh  0.66
7990:$1000 - 1340Mh 0.74

those of course are just guesses and could be completely wrong. And I also havnt included power consumption. Im just really torn between what to get. Or hell even spending all that money on just buying a bunch of LTC to keep and stimulate growth of the network by providing demand  

and with

Additionally the kernels totally suck balls right now for GCN, so this may improve over time.

 It could be wise to invest in the 7970s hoping that hashrate for these will increase ?

[tacotime]

I would buy 7970s if I were to buy more cards, although the efficiencies of the 7950s isn't that bad.  You can probably resell 7970s for 80% of their purchase value or so before the 8xxx series comes out Q1 next year, especially if LTC mining is popular then.  This is in contrast to the 6xxx series which will probably lose way more of its value as they can only be used for mining by then, as comparatively their gaming performance will probably be poor.

I think those numbers are higher than most people report too, but I know what my rig pulls idle with no cards in it (70W) whereas most people measure power consumption as the difference from idle to load (which is incorrect and will give you lower than actual).

The temperature where I live goes down to an average of -20C in the winter time, so come November my rigs (outdoor in a shed) should be sufficiently cooled to pull excellent efficiency.  The cards will have to probably mine at 800MHz in the summertime if I keep them that long, because the heat gets to be a bit much.

Currently the 7970s are pretty profitable to mine BTC with (I make $7 a day on a $1400 investment).  If the rigs continue to pull LTC after BTC at a similar rate or the price of either grows exponentially (since I hoard), I should still have made money in 6 months time.  You need to weigh it for yourself though, it is a gamble.

You can also try gambling with the LTC market by dumping about $10k into it progressively over a month and trying to get it to snowball upwards, but I think that's even more of a gamble.

You can probably rest assured that if all the GPU miners do move to LTC though, the LTC you save now will be worth a lot in the near future.

[obisunk]

[USA only?] There's a deal for 7970 if anyone's interested.  Supposed to does 700 kh/s on ltc.  Top tier gaming card too.

Diamond HD 7970 - $311.99 AC/AR w/ FS @ Newegg
original thread: http://hardforum.com/showthread.php?t=1719397

Instant rebate/coupon stacks but AR does not.

(Costs more than flashed 6950s for the same hash power [if you have free electricity], but considering the resale value and wattage, it might just be worth it)

[DiCE1904]

I would buy 7970s if I were to buy more cards, although the efficiencies of the 7950s isn't that bad.  You can probably resell 7970s for 80% of their purchase value or so before the 8xxx series comes out Q1 next year, especially if LTC mining is popular then.  This is in contrast to the 6xxx series which will probably lose way more of its value as they can only be used for mining by then, as comparatively their gaming performance will probably be poor.

I think those numbers are higher than most people report too, but I know what my rig pulls idle with no cards in it (70W) whereas most people measure power consumption as the difference from idle to load (which is incorrect and will give you lower than actual).

The temperature where I live goes down to an average of -20C in the winter time, so come November my rigs (outdoor in a shed) should be sufficiently cooled to pull excellent efficiency.  The cards will have to probably mine at 800MHz in the summertime if I keep them that long, because the heat gets to be a bit much.

Currently the 7970s are pretty profitable to mine BTC with (I make $7 a day on a $1400 investment).  If the rigs continue to pull LTC after BTC at a similar rate or the price of either grows exponentially (since I hoard), I should still have made money in 6 months time.  You need to weigh it for yourself though, it is a gamble.

You can also try gambling with the LTC market by dumping about $10k into it progressively over a month and trying to get it to snowball upwards, but I think that's even more of a gamble.

You can probably rest assured that if all the GPU miners do move to LTC though, the LTC you save now will be worth a lot in the near future.

some great input TacoTime, I appreciate it. I think ill be going with the 7970s for the time being even though at current rate I think it would cost about a year to pay it off completely.