First mining rig

[oddwh]

Hello guys,

During these last months, I used my graphic card from my PC for mining (a 7970 lightning). I'd like to get more power and buy 2*r9 280x. I'll put them on an old motherboard (asus p5q), with 4gb of ram and a c2d e8400.

I've a question about the psu :

- 800w is enough for 2*r9 280x ? Even if cards aren't undervolted ?

If it's enough, I know I can put 3 gpus on a P5Q, do you think 1000w is enough ?

About undervolting, does it remove the warranty ? I'm a bit afraid about that and I didn't find a true answer. I don't know if I undervolt a card if there is a way to see it when I return the card.

Sorry for my english and thanks 

[damnation]

For 2x r9 280x your looking at about 340w x2 = 720 w add another 200 w for the rest of your system (just in case) means that you would need at least a 1000w system for a 2 cards system and a 1250w for 3 cards.

Though some ppl have reported that the 1250 W was fine for 3x R9 280x  quite a few have also complaint that it was a little risky.

Running at full load a good "GOLD" rated PSU will be fine for 1250W.

[oddwh]

For 2x r9 280x your looking at about 340w x2 = 720 w add another 200 w for the rest of your system (just in case) means that you would need at least a 1000w system for a 2 cards system and a 1250w for 3 cards.

Though some ppl have reported that the 1250 W was fine for 3x R9 280x  quite a few have also complaint that it was a little risky.

Running at full load a good "GOLD" rated PSU will be fine for 1250W.

Thanks a lot for your answer, I didn't think a r9 280x use so much power 

Anyway, I still have my question about the warranty, if someone already had an experience with that, please answer 

[sandor111]

300w is plenty for a 280x, unless you plan on overvolting

[oddwh]

300w is plenty for a 280x, unless you plan on overvolting

hmm yeah, I don't will try to overclock the card, because I live in an appartment, and the card will become too noisy. I'm more thinking to an undervolting, but only if it doesn't remove the warranty (or only if they can't see it when I have to do a return)

I've read somewhere it's more around 250~300w, true ? that means with the factory voltage, it's possible to put 3 cards on one 1000w psu.

[damnation]

Check the below blog..

http://holynerdvana.blogspot.in/2013/11/litecoin-mining-with-r9-290-and-r9-290x.html

The blog has a decent build guide for R9 290's but just remember... the most important aspect of mining aint the GPU's its your PSU... so dont cheap out on it



https://bitcointalk.org/index.php?topic=7216.4240

chk post number 4255 and 4257

Note that comment- has hard time running 3 on 1000w without it crash

[oddwh]

Check the below blog..

http://holynerdvana.blogspot.in/2013/11/litecoin-mining-with-r9-290-and-r9-290x.html

The blog has a decent build guide for R9 290's but just remember... the most important aspect of mining aint the GPU's its your PSU... so dont cheap out on it



https://bitcointalk.org/index.php?topic=7216.4240

chk post number 4255 and 4257

Note that comment- has hard time running 3 on 1000w without it crash

thanks a lot  I searched some experiences and you gave me it