|
Title: 4 7850's or 2 7970's? Post by: SeanArce on June 19, 2013, 11:04:02 PM What's more promising?
Title: Re: 4 7850's or 2 7970's? Post by: SeanArce on June 20, 2013, 02:36:10 AM I want to feel apart of the bitcoin community. Which is a better option?
Title: Re: 4 7850's or 2 7970's? Post by: Gomeler on June 20, 2013, 04:34:32 AM 2x HD 7950s for litecoin. Mining BTC on GPUs isn't wise.
Title: Re: 4 7850's or 2 7970's? Post by: neo101one on June 20, 2013, 04:42:22 AM you might save money getting 4 7850s, but might need a bigger psu. the 2 7970s could run on a 750w psu.
Title: Re: 4 7850's or 2 7970's? Post by: SeanArce on June 20, 2013, 05:54:17 PM 2x HD 7950s for litecoin. Mining BTC on GPUs isn't wise. I'm going to be mining alternative crypto Title: Re: 4 7850's or 2 7970's? Post by: SeanArce on June 20, 2013, 05:55:30 PM you might save money getting 4 7850s, but might need a bigger psu. the 2 7970s could run on a 750w psu. How many watt psu for 4 7850's? Title: Re: 4 7850's or 2 7970's? Post by: BlazinBeaches on June 20, 2013, 05:59:09 PM 7850s draw about 130watt each
7950s are 200 7970s are 250 +/- plus mobo/cpu/ram plus 15% breathing room Title: Re: 4 7850's or 2 7970's? Post by: zackclark70 on June 20, 2013, 06:02:16 PM you can get 3 7950s for the price of 2 7970s and only need a good 750w psu ( i have a 3 card rig with 1950kh 720w from the wall )
Title: Re: 4 7850's or 2 7970's? Post by: zvs on June 20, 2013, 06:53:31 PM 7790's are about 15% slower than 7850's for bitcoins (duno about scrypt currencies).. they only use about 70-75 watts
Title: Re: 4 7850's or 2 7970's? Post by: TheSpiral on June 21, 2013, 09:26:51 AM 7790's are about 15% slower than 7850's for bitcoins (duno about scrypt currencies).. they only use about 70-75 watts They're very close for SHA, 7790's are much worse for scrypt.Title: Re: 4 7850's or 2 7970's? Post by: zackclark70 on June 21, 2013, 09:33:51 AM if you are mining any scrypt coin stick with 7950s if you can as thay have a higher resale value ( do not buy xfx )
Title: Re: 4 7850's or 2 7970's? Post by: rovchris on June 21, 2013, 11:45:48 AM Just out of interest why are 7850's better than 7970's
Title: Re: 4 7850's or 2 7970's? Post by: SeanArce on June 22, 2013, 03:51:27 PM Just out of interest why are 7850's better than 7970's I'm guessing its more cost effective and the initial price of the 7850 is a lot better Title: Re: 4 7850's or 2 7970's? Post by: The Extreme on June 25, 2013, 06:08:36 AM No contest...
4x 7850: Max Power Draw = 4*130W = 520 W Approx LTC Hashrate = 4*330 kH/s = 1.32 MH/s Kilohashes/Watt: 2.54 Upfront Cost = 4*$190 = $760 2x 7950: Max Power Draw = 2*180W = 360 W Approx LTC Hashrate = 2*620 kH/s = 1.24 MH/s Kilohashes/Watt: 3.44 Upfront Cost = 2*$300 = $600 2x 7970: Max Power Draw = 2*270W = 540 W Approx LTC Hashrate = 2*725 kH/s = 1.5 MH/s Kilohashes/Watt: 2.78 Upfront Cost = 2*$420 = $840 The 7950s are typically all but impossible to beat as a mining card for any non-BTC mining. In this example, the two 7950s have the cheapest upfront cost, consume the least power, and trounce the other options in terms of hashes per watt. It's my understanding that for mining, the Pitcairn-based boards are not the best option; for a mining rig, consider only Tahiti-based cards (7870XT or higher). That said, the 7950 is almost always the best bet, regardless of the number of cards. Hope this helps... Title: Re: 4 7850's or 2 7970's? Post by: rovchris on June 25, 2013, 06:22:42 AM No contest... 4x 7850: Max Power Draw = 4*130W = 520 W Approx LTC Hashrate = 4*330 kH/s = 1.32 MH/s Kilohashes/Watt: 2.54 Upfront Cost = 4*$190 = $760 2x 7950: Max Power Draw = 2*180W = 360 W Approx LTC Hashrate = 2*620 kH/s = 1.24 MH/s Kilohashes/Watt: 3.44 Upfront Cost = 2*$300 = $600 2x 7970: Max Power Draw = 2*270W = 540 W Approx LTC Hashrate = 2*725 kH/s = 1.5 MH/s Kilohashes/Watt: 2.78 Upfront Cost = 2*$420 = $840 The 7950s are typically all but impossible to beat as a mining card for any non-BTC mining. In this example, the two 7950s have the cheapest upfront cost, consume the least power, and trounce the other options in terms of hashes per watt. It's my understanding that for mining, the Pitcairn-based boards are not the best option; for a mining rig, consider only Tahiti-based cards (7870XT or higher). That said, the 7950 is almost always the best bet, regardless of the number of cards. Hope this helps... What about the fact that you would require additional motherboards, CPU's, PSU's to run more cards for the same Hash rate. Realistically you can only connect 4 cards to one motherboard and expect any kind of stability. When you factor in these additional costs and the power overhead of the additional hardware - I am not sure that the 7950's are better. Title: Re: 4 7850's or 2 7970's? Post by: The Extreme on June 25, 2013, 06:29:09 AM No contest... 4x 7850: Max Power Draw = 4*130W = 520 W Approx LTC Hashrate = 4*330 kH/s = 1.32 MH/s Kilohashes/Watt: 2.54 Upfront Cost = 4*$190 = $760 2x 7950: Max Power Draw = 2*180W = 360 W Approx LTC Hashrate = 2*620 kH/s = 1.24 MH/s Kilohashes/Watt: 3.44 Upfront Cost = 2*$300 = $600 2x 7970: Max Power Draw = 2*270W = 540 W Approx LTC Hashrate = 2*725 kH/s = 1.5 MH/s Kilohashes/Watt: 2.78 Upfront Cost = 2*$420 = $840 The 7950s are typically all but impossible to beat as a mining card for any non-BTC mining. In this example, the two 7950s have the cheapest upfront cost, consume the least power, and trounce the other options in terms of hashes per watt. It's my understanding that for mining, the Pitcairn-based boards are not the best option; for a mining rig, consider only Tahiti-based cards (7870XT or higher). That said, the 7950 is almost always the best bet, regardless of the number of cards. Hope this helps... What about the fact that you would require additional motherboards, CPU's, PSU's to run more cards for the same Hash rate. Realistically you can only connect 4 cards to one motherboard and expect any kind of stability. When you factor in these additional costs and the power overhead of the additional hardware - I am not sure that the 7950's are better. Hmmm... rovchris, I'm not sure I follow. I agree with your assessment that 4 GPUs is the realistic maximum on any one mobo. But with the 7950's (or 7970's, for that matter) he would only need two cards instead of four. One more advantage to the 79xx cards... Title: Re: 4 7850's or 2 7970's? Post by: rovchris on June 25, 2013, 06:46:45 AM Sorry man I was not very clear.
I was just saying in the situation where lets say you wanted to build a 10mhs rig (scrypt) - you would require more cards if you using the 7950's and hence more of all the supporting hardware. In this situation though as the OP only wanted to build a rig of a set size you make a very good case. I was just picking the experts brains here! Title: Re: 4 7850's or 2 7970's? Post by: chadtn on June 28, 2013, 10:59:55 AM I was able to get away with running two 7970's on a 660 watt power supply for a couple of weeks with no problem. I decided to upgrade before I started over clocking the cards though.
Chad Title: Re: 4 7850's or 2 7970's? Post by: Equate on June 28, 2013, 12:57:07 PM 2 7950 better than 2 7970 if you want to mine LTC
Title: Re: 4 7850's or 2 7970's? Post by: Eastwind on June 28, 2013, 02:16:01 PM you can get 3 7950s for the price of 2 7970s and only need a good 750w psu ( i have a 3 card rig with 1950kh 720w from the wall ) I think it is better option. 7950 works better than 7850 on LTC, as the memory bandwidth of 7950 is 384 bit instead of 256 bit. memory bandwidth matters on LTC mining. Title: Re: 4 7850's or 2 7970's? Post by: ohiwastedmylif on June 28, 2013, 07:02:01 PM 7970 are now on sale for $300, vapor-x 7970 for $330 range, all with 4 games that can be sold for about $50 if you are lucky.
Slickdeals is your friend if you do not need tons of them. You can pick up a few for really cheap every other week when new rebates come out. We will see $200 7950's and $260-$275 7970's this fall. Title: Re: 4 7850's or 2 7970's? Post by: Galimore on June 28, 2013, 07:17:44 PM No contest... 4x 7850: Max Power Draw = 4*130W = 520 W Approx LTC Hashrate = 4*330 kH/s = 1.32 MH/s Kilohashes/Watt: 2.54 Upfront Cost = 4*$190 = $760 2x 7950: Max Power Draw = 2*180W = 360 W Approx LTC Hashrate = 2*620 kH/s = 1.24 MH/s Kilohashes/Watt: 3.44 Upfront Cost = 2*$300 = $600 2x 7970: Max Power Draw = 2*270W = 540 W Approx LTC Hashrate = 2*725 kH/s = 1.5 MH/s Kilohashes/Watt: 2.78 Upfront Cost = 2*$420 = $840 The 7950s are typically all but impossible to beat as a mining card for any non-BTC mining. In this example, the two 7950s have the cheapest upfront cost, consume the least power, and trounce the other options in terms of hashes per watt. It's my understanding that for mining, the Pitcairn-based boards are not the best option; for a mining rig, consider only Tahiti-based cards (7870XT or higher). That said, the 7950 is almost always the best bet, regardless of the number of cards. Hope this helps... Every single thing in your 7850 calculation is wrong. Brand new 7850's are $140 at newegg, mine hash at ~375 on a pretty mild overclock (and still run at <60*C at 75% fan), and draw slightly more than 110w each. I'm running two sets of four on 800w power supplies and haven't had a single issue in the three months I've had them. During the Never Settle deal they were actually only ~$120 after you sold the codes. http://www.newegg.com/Product/Product.aspx?Item=N82E16814202004 Title: Re: 4 7850's or 2 7970's? Post by: 12gaFacelift on June 28, 2013, 07:53:29 PM 4 in the same box i hope its open because its what i use here, 4x MSI Radeon HD R7850 Power Edition 2GD5/OC and the box need much fresh air.
Title: Re: 4 7850's or 2 7970's? Post by: Mapuo on June 28, 2013, 08:00:03 PM 7850 - 400 kh/s, not 330, 350 or 375.
Title: Re: 4 7850's or 2 7970's? Post by: 12gaFacelift on June 28, 2013, 08:07:04 PM 400? say to me then because i hit 355 only with cgminer
the box in question: Box : Cooler Master HAF X Motherboard : Asus Maximus V Extreme Processor : Intel Core i7-3770 Quad Core 3.4 Ghz CPU Cooler : Cooler Master Hyper 612 PWM Graphic Card : 4 x MSI Radeon HD 7850 PE OC Memory : 4 x 4Gb Kingston HyperX Blu Black Series DDR3-1600 CL9 Power supply : Corsair Professional Series Gold CMPU-1200 1200W *I dont use the box only for mining but also for host my file Title: Re: 4 7850's or 2 7970's? Post by: Mapuo on June 28, 2013, 08:48:46 PM 400? say to me then because i hit 355 only with cgminer "intensity" : "12",the box in question: Box : Cooler Master HAF X Motherboard : Asus Maximus V Extreme Processor : Intel Core i7-3770 Quad Core 3.4 Ghz CPU Cooler : Cooler Master Hyper 612 PWM Graphic Card : 4 x MSI Radeon HD 7850 PE OC Memory : 4 x 4Gb Kingston HyperX Blu Black Series DDR3-1600 CL9 Power supply : Corsair Professional Series Gold CMPU-1200 1200W *I dont use the box only for mining but also for host my file "worksize" : "256", "kernel" : "scrypt", "lookup-gap" : "2", "thread-concurrency" : "4800", "shaders" : "1024", "gpu-engine" : "1150", "gpu-fan" : "0-100", "gpu-memclock" : "1250", "gpu-vddc" : "1.108", "temp-cutoff" : "95", "temp-overheat" : "85", "temp-target" : "70", "auto-fan" : true, "expiry" : "1", "gpu-threads" : "2", "queue" : "1", "scan-time" : "1", "scrypt" : true, "temp-hysteresis" : "1", "kernel-path" : "/usr/local/bin" 7850 - 400 kh/s, not 330, 350 or 375. I can get 400 with extreme OC and voltage occasionally but the WU ration and stability suck. ~BCX~ Title: Re: 4 7850's or 2 7970's? Post by: Mapuo on June 29, 2013, 12:40:56 AM I cant, but I know everything for 7850.
Regards |