how old the mobos we are talking about?
if a 775 platform is old enough to you,then the answer is yes you can, and there is no impact on your hash rate for both btc or ltc mining.
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I prefer Asus but bought Gigabyte because the Asus cards were sold out. start /D "C:\cgminer" cgminer.exe --scrypt -o coinotron.com:3334 -u Worker.1 -p x --thread-concurrency 8192 -I 13 --lookup-gap 2 --worksize 256 -g 2 -d 0 -d 1 --gpu-memclock 1600,1600 --shaders 2048 --gpu-engine 1050,1050 --gpu-fan 60,60
![](https://ip.bitcointalk.org/?u=http%3A%2F%2Fi146.photobucket.com%2Falbums%2Fr254%2FMaGNeT76%2Fsmooth7970_zps99b004dc.jpg&t=665&c=2VeeihinsfJOkg) do you undervolt your cards? or keep them at stock voltage?
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a quick question, does it really matter which crystal/SDK to use for 7900 series cards? I haven't paid any attention to this.
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nice card, specially the temp is good. my cards can only work at about 630, ![Sad](https://bitcointalk.org/Smileys/default/sad.gif)
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I also want to know the same thing, so up up up ![Wink](https://bitcointalk.org/Smileys/default/wink.gif)
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I have the same Powercolor card. The main issue you're going to run into is that the cooling solution sucks balls. I have 7 other 7970s running at 680 kh, but that one can only run at 550 to keep it cool. I had the same issue with it mining BTC. Other cards at 1110 / 170 pulling 640 mh/s, but that one could only run up to 1080 and it was running at 100% fan.
are we talking about the same card? this is the one I am referring to http://www.powercolor.com/us/products_features.asp?id=398I have some different experience with these cards, the 7970s I have can mine with little noise at 630 each and it keeps the temp at 70 (the one closest to the CUP) and 68 for the other one. (my wife even ask me to sell all my reference 7950s to get all this kind of 7970, noise really kills her ![Cheesy](https://bitcointalk.org/Smileys/default/cheesy.gif) ) Exact same card. My 6870x2 failed and they sent me that as an RMA replacement for it. The rig that cotains this card has 3x7970s in it. I have this card on a riser where the other two are onboard, but as far away from each other as possible. Ambient temperature ranges right now from 67-80 F in an extremely well ventilated space. The two onboard run 675 kh around 55-60% fan while this card can't even hit the clocks necessary because it overheats. With the fan at 100% the card keeps getting warmer, warmer, and warmer, until I have to close cgminer to let it cool down. Perhaps, I got a lemon, but out of my 7970s (6 visiontek reference, 1 sapphire dual fan, and this powercolor) this one is easily the worst. Noise, doesn't bother me as my rigs are a on the first floor, but if it was I'd go with this card: http://www.newegg.com/Product/Product.aspx?Item=N82E16814102982R . I bought it open box last year and it easily the best in regards to noise, cooling, and the ability to overclock. Well, if that's a replacement from RMA, the chance is that's a repaired card....so they maybe fixed something and screwed up something else. I am sure you have already swap position with the onboard cards, maybe another RMA?
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6 - 12 month? most cards will still be covered by warranty ![Cheesy](https://bitcointalk.org/Smileys/default/cheesy.gif) I am only comfortable when temp < 75, using extend cable does help as well as running the miner naked. I am seeing the temp difference in/outside the case is abou t 5-6 degree, and the extend cable connected cards are running also 5-6 degree less, so that adds up about 10 degree difference. ![Grin](https://bitcointalk.org/Smileys/default/grin.gif)
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I have the same Powercolor card. The main issue you're going to run into is that the cooling solution sucks balls. I have 7 other 7970s running at 680 kh, but that one can only run at 550 to keep it cool. I had the same issue with it mining BTC. Other cards at 1110 / 170 pulling 640 mh/s, but that one could only run up to 1080 and it was running at 100% fan.
are we talking about the same card? this is the one I am referring to http://www.powercolor.com/us/products_features.asp?id=398I have some different experience with these cards, the 7970s I have can mine with little noise at 630 each and it keeps the temp at 70 (the one closest to the CUP) and 68 for the other one. (my wife even ask me to sell all my reference 7950s to get all this kind of 7970, noise really kills her ![Cheesy](https://bitcointalk.org/Smileys/default/cheesy.gif) )
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Work in progress: ![](https://ip.bitcointalk.org/?u=http%3A%2F%2Fi146.photobucket.com%2Falbums%2Fr254%2FMaGNeT76%2Fhetframeisklaar_zps154ffbdc.jpg&t=665&c=p27dtx2d8s9uXg) Now waiting for the 2x HD7970 cards ![Smiley](https://bitcointalk.org/Smileys/default/smiley.gif) that's a good design, I am thinking something like this, my previous design isn't that stable for the "second floor" cars.
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thats why most guys buy 7950 for LTC mining ...
true, my 7950 with reasonable OC can mine at 550, and some ppl use their MSI WC mine at 600 but the price of a MSI WC is almost the same as the 7970 I got...... being the owner of 5 7950's (all gigabyte) and having got my first 7970 yesterday (sapphire dual x)... 7950's are ABSOLUTELY the winner for value. 650 on a 7950 vs 710 on a 7970... its a no-brainer.. the 7970 i'll use as a gaming card this summer when i shut down my mining due to heat ![Smiley](https://bitcointalk.org/Smileys/default/smiley.gif) Agree, heard some 7950 can hash > 600, but my reference cards only stays at 550 or I haven't find their sweat spots. However price wise those "healthy" 7950s are also pricey, I remember the MSI 7950 is about $300 each (without any AMD Promo coupon or AIR), so I end up pay about $25 more for a 7970, that's after tax and delivery ![Smiley](https://bitcointalk.org/Smileys/default/smiley.gif) Last thing I haven't figure out is, with lower core/memory frequency to achieve same hash rate, say 630Kh/s, does this mean a 7970 consume less power than a heavy OC'd 7950? (I saw my friends OC their MSI 7950 to 1050 core, 1700 memory to get about 610Kh/s @ 1.1xx voltage, compare with my 7970 with 920/1672 @1.018)
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after about 1 hour of tweak..... I finally found sweat spots of these two cards. for me the 0.57 ratio is the highest I can set for core/mem I finally set the ratio to be 0.55 with core @ 915 now both mining @ 620-630 @ 1.018 voltage
so I guess it's still energy efficient at this speed.
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thats why most guys buy 7950 for LTC mining ...
true, my 7950 with reasonable OC can mine at 550, and some ppl use their MSI WC mine at 600 but the price of a MSI WC is almost the same as the 7970 I got......
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it's interesting, yesterday I lower the core to 912 and the memory clock to 1600, and lower the -w to 128, @ 1.063v one card can mine stable at 600 and the other at 550.....
seems they have some different quality? or LTC mining has some dependency on how good the rig is? I mean I am running it on a 775 platform with 4G of DDR2 RAM does this impact the speed?
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just picked up two powercolor 7970 v3 today, and its voltage is unlocked (both direction) but I can't manage to make it hash over 600K get 600K with reaper get 550K with CG 2.11.4 I try to keep the 0.57 ratio and set the core to 970 and memory to 1700 it's stable at 1.063v but the hash rate is not ideal.. ![Cry](https://bitcointalk.org/Smileys/default/cry.gif)
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forgive me for asking this question, what's the advantage to run on 220v, I mean in north american. thanks.
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I've been through Every Newegg and Amazon card as well as Tiger Direct, Microcenter and Fry's.
I can't find a single 7970 that has unlocked voltages.
I'm going 7950 I guess.
actually I just got two of powercolor 7970 V3, and they have unclocked voltage and with dual fan configuration it mines very quite the only drawback is I haven't been able to mine LTC over 550Kh/s
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and you can find cheaper CPU as well CPU only server the purpose to fill the whole on mobo, so your system can boot, ![Cheesy](https://bitcointalk.org/Smileys/default/cheesy.gif)
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reaper asks for 1.5g RAM for each 7950......
Consider HX 850, that's the PSU so far I found has 6 * 6 pins for 3 cards, I am still digging
I have one, and it has 6 connectors with 8 pins each. I found two of this HX850 from the Internet, One it says HX series HX850 the other one has Professional Series HX850, and one is 80 Plus silver the other one is 80 Gold I am confused......
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i don't have first hand info. But I read people say flash to fx2 solves the problem I am still thing about this card, how is the temp when you are mining?
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.....was thinking to get this one, it seems cheaper but without unlocked voltage......Er.....no
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