$4k for a rig
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I would invest in a larger power supply and a mobo that can take 3 to 4 cards. But if you are just reusing, I don’t see why not.
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7850 is around $140/ea and can give you in the area of 350Kh/s per card.
I personally use the Sapphire 3GB 7950 which I got for $270 and I am currently getting 650Kh/s.
7850 will require 2x the cards, 2x the PCI slots, maybe 1.5x the power consumption.
Either way the 400 watt psu seems a little low for 2x 7850. I do not have one though so I have no clue about the overclocking effects on consumption.
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The 450W will struggle with 2 x 7850, but it will run 1 x 7850. It all depends on the PSU you have and how much current it supplies to the 12V rail. My mining rig started out as a 7850 with a 450W PSU. I found that if i loaded the cgminer with intensity 19 the PSU would shut down instantly which i suspect is due to the PSU not handling the high inrush current. However the PSU would hold up if i gradually increased the intensity from 10 to 19. All in all i was able to manage an average of 385kH/s on the 7850 with the 450W PSU. I purchased a second 7850 today and upgraded the PSU to 650W. Both cards are producing an average of 385kh/s and so far are rock solid with no hardware errors.
The cards I’m using are Sapphire 2GB
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here’s how i would spend *your* money :P
9 - MSI twin frozr 7950s - $313ea - $2817
3 - Athlon II 235e /240e/245e or sempron145 - $30ish off ebay - $90
1 - 8b ddr3 pc1600 (you have 32 gb already, type unknown though) - $60ish
1 - sata hard drive (you should have at least 2 drives already) - $60ish
3 - red crates from lowes -$6ea -$18
3 - gigabyte 970a-d3 - $81 ea - $243
3 - corsair HX 1050 PSU - $220eac - $660
9 - pci-e 1x risers (i get mine from bitmit with btc) $3 - $27roughly $3900
estimated output - 5400Kh @2200watts
8) -
I agree with deroekeloze, the 7950s are the best bang for the bucks. I have 6x 7970s and although some get 750 Kh/s, some are at 680 kh/s.
Get as many 7950s working at possible!
I very much like the red crates idea, I need that :)
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[quote name=“deroekeloze” post=“7478” timestamp=“1369748637”]
[IMG]http://i.imgur.com/z5PQxLq.jpg[/img]
[/quote]Is anyone selling these pre-made yet?
‘The Crate’ for $1599 ready to go. $ $ $
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I’m working on the crate method right now as well. I’m just waiting for one more package and I’ll have mine setup. Here’s essentially what I bought (and realize I may have over engineered slightly).
1x ASRock MB-970EX4 ATX MB
1x ATX Power Supply Power Switch
4x Gigabyte AMD Radeon HD 7950 3GB
1x Seasonic SS-1250XM X-Series ATX PC Power Supply
1x Powered PCI 16x to PCI 1x riser
3x Powered PCI 16x to 16x riser
1x 4GB 1333MHz DDR3
1x Sempron 145 processorAt the moment I’m in for ~$1600 roughly. I have of old hard drives sitting around but I’m sure you can do a low scale linux install on just a usb memory key. So other parts and whatever I can scrounge up around the house I’ll probably end up spending another $10-$20 or less.
I went for the “powered” riser cards which have a plug for the power supply because this should help take the load off the motherboard to supply that power.
One other thing that NutNut pointed out in one of his posts is that you don’t really need a lot of memory. I think he said something along the lines of cgminer was using about 150megs ram to do its thing. 4gigs ram is fairly relatively cheap if you look around though but I don’t see any reason to have 8. Also the CPU doesn’t make any difference so there’s no reason to spend a lot there either.
Hope this helps!
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[quote]you don’t really need a lot of memory[/quote]
my personal experience with 7950s has been quite the opposite. my 7950 would not do anything over intensity 13 but throw hardware errors with 2 gig of pc1333. i swapped ram between rigs, throwing the 2 gig in my 5850 rig and 8 gig pc1600 gig into the 7950 rig. after re-running the setx commands on both boxes, the 7950 was able to do intensity 20 with no errors. this yielded about 100Kh bump in hashing speed and the 5850s continue happily onwards kickin out their 1.1Mh, 24/7. also with 2 gig in the 7950 box, i couldn’t run thread concurrency over 10K or so without cgminer throwing a nasty fit and calling me names. after the swap, TC set to 24K ran without a hitch. 5850’s TC remained at 8K with both types of ram, zero problems.
most of what i have read recommends at least 2 gig of ram per 7950, but a buddy of mine runs a few rigs with just 2 gig and has zero problems. it could simply come down to hardware configuration, karma, holding your mouth just right when assembling, or just plain old magic ::)
as with anything written on the internet, your mileage may vary 8)
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will give my 5cent in a little bit.
have tried allmost all the different card modell:) -
$1,650 gets you about 2.6 MH on a crated rig with 4x7950 of the Gigabyte WF3s.
I’ve built about 12 rigs thus far, and what zythen quoted was about what you want… All depends if you want AMD or Intel. I prefer Intel, which loves the Z77A motherboard.
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[quote name=“zythen” post=“7529” timestamp=“1369758957”]
1x ASRock MB-970EX4 ATX MB
4x Gigabyte AMD Radeon HD 7950 3GB
1x Powered PCI 16x to PCI 1x riser
3x Powered PCI 16x to 16x riser
[/quote]You can run 4 cards on 1 mobo? I was not aware you can use a card on a PCI 1x.
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[quote name=“ASDASDASD” post=“7551” timestamp=“1369762086”]
[quote author=zythen link=topic=936.msg7529#msg7529 date=1369758957]
1x ASRock MB-970EX4 ATX MB
4x Gigabyte AMD Radeon HD 7950 3GB
1x Powered PCI 16x to PCI 1x riser
3x Powered PCI 16x to 16x riser
[/quote]You can run 4 cards on 1 mobo? I was not aware you can use a card on a PCI 1x.
[/quote]Yes no problem. just use an extention cable from 1x-16x
Ive been trough these cards:
7990 = 1100khash
7970 = 550khash
7950 = 560khash
7850 = 240 khash
6970 = 450khash
6950 = 400khash
6870 = 250 khash
5870 = 380Khash
5830 = 250 khashAll these values are based on average of all the versions, running at stock engine/memclock and kept around/below 80 degres
5830/6870/7850 i would not bother, takes up to much space/psu connectors to be worth it…
6950/6970 works very well but they DO produce a shitload of heat, when i removed my 5x6970 rig the entire room temp went WAY down…
7990 got damn that cards get hot/noicy! i was planing to use 2x in my main gaming rig, but even when i have XL case and 5x140mm fans for air circulation the 2nd card chocked card 1 due to heat…
7970 is to overpriced vs hashrate, i get like 580khash with my gigabyte ghz editions…7950, i got 6x sapphire 7950 http://www.sapphiretech.com/presentation/product/?cid=1&gid=3&sgid=1157&pid=1481&psn=&lid=1&leg=0
now theese cards surpriced me so much i ended up ordering 15 of them, and are now in the process of changing out all of my current 23 graphic cards…
Im able to push 560khash with everything at stock (I18) and everything runs smooth at around 78degrees in an warm room!Running 3x7950 works like a charm with either an corsair 800w or an silverstone 850w. no trouble at all.
They produce amazingly little heat (compared to many others). also they need 2x 6pins connectors instead of 1x8+1x6pins, adapters for 1xmolex to 1x6pins comes in package (nice surprice), all my adapters needed two molex, so seeing it be able to run on one is excellent for cable management ::) -
[quote name=“ASDASDASD” post=“7551” timestamp=“1369762086”]
[quote author=zythen link=topic=936.msg7529#msg7529 date=1369758957]
1x ASRock MB-970EX4 ATX MB
4x Gigabyte AMD Radeon HD 7950 3GB
1x Powered PCI 16x to PCI 1x riser
3x Powered PCI 16x to 16x riser
[/quote]You can run 4 cards on 1 mobo? I was not aware you can use a card on a PCI 1x.
[/quote]Yup! All those additional pins on the card are just more data channels for bandwidth through the MB Bus. You could tape them off to drop the card down to a 8x or 4x if you wanted, although I’m not certain for what reason you would need or want to. It’ll still work as a video card though.
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One last note - If you’re an Amazon Prime member, meaning you have the $79/year membership to get 2day free shipping, I’ve been buying a lot of computer parts cheaper there than on Newegg recently. I make that $79 back in spades every year on everything I buy and have shipped free as well as tax free.
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[quote name=“deroekeloze” post=“7539” timestamp=“1369760377”]
[quote]you don’t really need a lot of memory[/quote]my personal experience with 7950s has been quite the opposite. my 7950 would not do anything over intensity 13 but throw hardware errors with 2 gig of pc1333. i swapped ram between rigs, throwing the 2 gig in my 5850 rig and 8 gig pc1600 gig into the 7950 rig. after re-running the setx commands on both boxes, the 7950 was able to do intensity 20 with no errors. this yielded about 100Kh bump in hashing speed and the 5850s continue happily onwards kickin out their 1.1Mh, 24/7. also with 2 gig in the 7950 box, i couldn’t run thread concurrency over 10K or so without cgminer throwing a nasty fit and calling me names. after the swap, TC set to 24K ran without a hitch. 5850’s TC remained at 8K with both types of ram, zero problems.
most of what i have read recommends at least 2 gig of ram per 7950, but a buddy of mine runs a few rigs with just 2 gig and has zero problems. it could simply come down to hardware configuration, karma, holding your mouth just right when assembling, or just plain old magic ::)
as with anything written on the internet, your mileage may vary 8)
[/quote]What program were you using to mine with? Reaper usually needs 1.5 GB per card, whereas CGMiner needs ~100MB.
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[quote]What program were you using to mine with? Reaper usually needs 1.5 GB per card, whereas CGMiner needs ~100MB[/quote]
CGMiner *shrug*
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i run two gb ram on my 7950 rigs no problem
with several cards.however i needef to remove shader and thread concurrency and let
cgminer chose this itself. if i try anything other.
even the values collected from .bin file i get hw error. -
[quote name=“svennand” post=“7640” timestamp=“1369782148”]
i run two gb ram on my 7950 rigs no problem
with several cards.however i needef to remove shader and thread concurrency and let
cgminer chose this itself. if i try anything other.
even the values collected from .bin file i get hw error.
[/quote]
i’m willing to bet a ram increase would cure it
cgminer probably sets default TC at 8190 with worksize 256 too right? any intensity past 13 cause the errors? that’s what mine did until i opted for more ram :P
call me crazy, but more ram fixed my rig 8) -
[quote name=“deroekeloze” post=“7648” timestamp=“1369783217”]
[quote author=svennand link=topic=936.msg7640#msg7640 date=1369782148]
i run two gb ram on my 7950 rigs no problem
with several cards.however i needef to remove shader and thread concurrency and let
cgminer chose this itself. if i try anything other.
even the values collected from .bin file i get hw error.
[/quote]
i’m willing to bet a ram increase would cure it
cgminer probably sets default TC at 8190 with worksize 256 too right? any intensity past 13 cause the errors? that’s what mine did until i opted for more ram :P
call me crazy, but more ram fixed my rig 8)
[/quote]Nope, nothing to do with the ram.
Tried inputing both 8,16, and even on my 32GB ram Rig i get the same error as long as i try to specify threads/shaders myself. according to bin it chooses something like 20k
