The one thing Bitcoin has taught me is that PSU are the unsung heroes of the computing world. 
Hear, hear. Gone are the days for me of clicking 'lowest price' sorting and picking the first one that meets the wattage requirements.
Topic: I have 3 5970s on the way; now what? - page 2. (Read 4520 times)
Hear, hear. Gone are the days for me of clicking 'lowest price' sorting and picking the first one that meets the wattage requirements.
An 80 Plus Gold PSU is going to cost you about the same as a bronze or silver 1200 w PSU. You'll also be running the PSU at 80+% capacity 24/7 ... most PSU operate most efficiently at ~50 - ~60% load, not 80%... so your cost over time is going to be higher running a 1KW PSU as well.
While I don't believe any of my sub 1.2KW PSUs were 80plus GOLD rated, they were quality PSUs (Corsair, etc) and they had stability problems if I put in more than 2 5970's along with 5870's. Moving to a 1200w let(s) me put 3 5970's and 1 5870 on the same rig. Anything less and the rig becomes unstable. Swapping one of the 5970's with a 5870 on a sub 1200w PSU and things become stable again.
Like I said, maybe an 80 plus gold would be different, but for the cost difference, my money is on 1200w.
While I don't believe any of my sub 1.2KW PSUs were 80plus GOLD rated, they were quality PSUs (Corsair, etc) and they had stability problems if I put in more than 2 5970's along with 5870's. Moving to a 1200w let(s) me put 3 5970's and 1 5870 on the same rig. Anything less and the rig becomes unstable. Swapping one of the 5970's with a 5870 on a sub 1200w PSU and things become stable again.
Like I said, maybe an 80 plus gold would be different, but for the cost difference, my money is on 1200w.
Interesting alternative view. It is amazing how important the PSU ends up being. Then again we are pushing these machines far beyond what they were ever intended to do. Maybe i just go lucky w/ good PSU. A lot depends on not just the wattage, but rail configuration, quality of the regulation etc.
One PSU might have nearly perfect regulation @ 60% load but goes to crap at 80% load.
Another might have more variability in voltage @ 60% load but isn't much worse at 80% load.
For the record my rigs all have 3x5970 running on either:
1000W model http://www.newegg.com/Product/Product.aspx?Item=N82E16817171056
1200W model http://www.newegg.com/Product/Product.aspx?Item=N82E16817171055
My workstation (4x5970 water cooled) uses this beast:
1350W http://www.newegg.com/Product/Product.aspx?Item=N82E16817194092
A little too expensive for mining rigs but I use the workstation more for just mining. It is an awesome PSU the only con would be the price. Nice thick heavy cables, quality cable wraps, all the cables are modular (including ATX 24 pin) which is useful when you need to get into that case crammed w/ 4 dual GPU cards and water cooling gear.
The one thing Bitcoin has taught me is that PSU are the unsung heroes of the computing world.
Quick question do you run your rigs @ 230V? Either at home or in your datacenter. I am thinking about maybe running a pair of 230V 30A lines in my garage to squeeze another 5% or so efficiency out of the rigs as well as move them all to dedicated circuits.
An 80 Plus Gold PSU is going to cost you about the same as a bronze or silver 1200 w PSU. You'll also be running the PSU at 80+% capacity 24/7 ... most PSU operate most efficiently at ~50 - ~60% load, not 80%... so your cost over time is going to be higher running a 1KW PSU as well.
While I don't believe any of my sub 1.2KW PSUs were 80plus GOLD rated, they were quality PSUs (Corsair, etc) and they had stability problems if I put in more than 2 5970's along with 5870's. Moving to a 1200w let(s) me put 3 5970's and 1 5870 on the same rig. Anything less and the rig becomes unstable. Swapping one of the 5970's with a 5870 on a sub 1200w PSU and things become stable again.
Like I said, maybe an 80 plus gold would be different, but for the cost difference, my money is on 1200w.
Also - I'd try to make sure you got a single rail design. I've had nothing but trouble trying to balance multi-rail GPUs when you're sucking down amps with dual GPU cards hanging off them on every rail.
While I don't believe any of my sub 1.2KW PSUs were 80plus GOLD rated, they were quality PSUs (Corsair, etc) and they had stability problems if I put in more than 2 5970's along with 5870's. Moving to a 1200w let(s) me put 3 5970's and 1 5870 on the same rig. Anything less and the rig becomes unstable. Swapping one of the 5970's with a 5870 on a sub 1200w PSU and things become stable again.
Like I said, maybe an 80 plus gold would be different, but for the cost difference, my money is on 1200w.
Also - I'd try to make sure you got a single rail design. I've had nothing but trouble trying to balance multi-rail GPUs when you're sucking down amps with dual GPU cards hanging off them on every rail.
No, a 1KW PSU will not power 3 5970's in a stable configuration. Many, many of my initial problems when building my bitcoin rigs turned out to be power related. Once I switched exclusively to 1200w PSUs, 90% of my stability problems went away. Running at the threshold of a PSU will induce all sorts of intermittent problems that are nearly impossible to track down.
It depends on the system as I indicated if you are building a general purpose computer which also mines then go 1200W but 100W is fine (check individual rail amperage) for a dedicated 3x5970 rig.
Sempron 145 (underclocked to 2GHz).
2GB RAM
4GB flash drive running linux coin.
3x5970s. (820 core & 160 Mhz memory)
80Plus-Gold PSU.
everything not needed turned off in bios (usb3, IDE, SATA controller, onboard sound, etc).
Pulls 870W at the wall. That is AC wattage. Back out (at least) 10% for PSU inefficiency and it is ~800W DC. That is 80% of 100W rated load.
Now before anyone half reads this and does something stupid. 1000W is fine for a USB linux only system properly optimized to reduce non-GPU powerload and w/ proper GPU memory underclocked (huge wattage saver). If you can't / won't do that then go 1200W at least.
So a 1000W PSU should be enough, even with a HDD? --I might decide to do some SW development with this system.
No, a 1KW PSU will not power 3 5970's in a stable configuration. Many, many of my initial problems when building my bitcoin rigs turned out to be power related. Once I switched exclusively to 1200w PSUs, 90% of my stability problems went away. Running at the threshold of a PSU will induce all sorts of intermittent problems that are nearly impossible to track down.
+1000000000
This is why ALL of my rigs are dual PSU to specifically avoid this problem. Dual PSUs are almost always less expensive than a single PSU of the same wattage so there is also cost savings in dual PSUs, even if you have to buy the dual PSU adapter.
So a 1000W PSU should be enough, even with a HDD? --I might decide to do some SW development with this system.
No, a 1KW PSU will not power 3 5970's in a stable configuration. Many, many of my initial problems when building my bitcoin rigs turned out to be power related. Once I switched exclusively to 1200w PSUs, 90% of my stability problems went away. Running at the threshold of a PSU will induce all sorts of intermittent problems that are nearly impossible to track down.
I would recommend you do something like this:
These are a couple of rigs I have running. PM me if you would like some details.
These are a couple of rigs I have running. PM me if you would like some details.
You move out of the dc or you have some at home too?
This is a picture of them being burnt in at my house before being moved to the DC. I will details the specs when I get a free moment.
The rig so far...
Ordered:
3x 5970 GPU
1x Corsair 1200AX PSU
1x Acrylic Open Computer Case
Planned:
MSI 890FXA-GD70 motherboard containing Sempron 145 CPU and 1G RAM (used)
Ordered:
3x 5970 GPU
1x Corsair 1200AX PSU
1x Acrylic Open Computer Case
Planned:
MSI 890FXA-GD70 motherboard containing Sempron 145 CPU and 1G RAM (used)
Usual comment about Linux ...
See my sig - and yeah use cgminer - coz only the best will do
(if you're going to use a hard drive to make it more reliable booting, you can still use that script but instead select to install to HDD after you boot the CD in your mining rig and you get to the screen that gives you that option)
See my sig - and yeah use cgminer - coz only the best will do
(if you're going to use a hard drive to make it more reliable booting, you can still use that script but instead select to install to HDD after you boot the CD in your mining rig and you get to the screen that gives you that option)
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The other advantage of 1200W is that if you later change your mind you could build an open extended frame, buy 4 extenders, add one more 5970 and convert it into a 4x5970 rig (~3GH/s).
I would recommend this. If bitcoin goes up you'll be happy, if bitcoin goes down its pretty safe to say you'll have a computer you'll be happy with for some years down the road. The 890 is an AM3+ board so you can always grab a 6 core later on down the road.Quote
I know this isn't frugal, but do you think this $50 acrylic open case would work?
I have seen this being used, AceJam I believe, and it works good.It's a bit more oddball, but a shoe rack works good too!
(with the use of extenders of course) I know from another post of yours elsewhere that you use the MSI 890FXA-GD70; that's what I'm planning to use.
Yup that is the one.
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I know this isn't frugal, but do you think this $50 acrylic open case would work?
A little pricey but it would work fine. Hell just a MB sitting on a MB box works fine (I ran 4 rigs that way for over a month).
I use a pair of 120mm fans laying "on top" across the 3 video cards to aid in airflow. That plus GPU fans clocked at 70% keep everything cool and stable. If you want it a little quieter in winter you probably can get away w/ 60% fan speed but you might need to turn down the clocks 5% or so.
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So a 1000W PSU should be enough, even with a HDD? --I might decide to do some SW development with this system.
The 870W is a sempron CPU (underclocked to 2Ghz from 2.8Ghz), usb drive running linuxcoin, GPU RAM underclocked to 160MHz, no HDD, everything unrelated to mining turned off in the bios (USB3, sata, onboard sound, etc) and a 80Plus-GOLD PSU. If you are going to put in a decent CPU and use it for general purpose computing if it were me I would go for 1200W PSU. 1000W would be fine for an optimized dedicated mining rig.
The other advantage of 1200W is that if you later change your mind you could build an open extended frame, buy 4 extenders, add one more 5970 and convert it into a 4x5970 rig (~3GH/s).
If you are willing to open mount them you can use a normal ATX MB without using extenders.
You just need a MB w/ a slot configuration:
PCIEx16
anything - unused
anything - unused
PCIEx16
anything - unused
anything - unused
PCIEx16
I know from another post of yours elsewhere that you use the MSI 890FXA-GD70; that's what I'm planning to use.You just need a MB w/ a slot configuration:
PCIEx16
anything - unused
anything - unused
PCIEx16
anything - unused
anything - unused
PCIEx16
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I run 3x5970s (6 GPU) that way just fine. Granted this is w/ no case. I simply have the MB mounted to an ATX MB tray (w/ expansion slots to support the video cards).
I know this isn't frugal, but do you think this $50 acrylic open case would work?Quote
~2300 MH/s per rig and 870W @ the wall.
So a 1000W PSU should be enough, even with a HDD? --I might decide to do some SW development with this system.
If you are willing to open mount them you can use a normal ATX MB without using extenders.
You just need a MB w/ a slot configuration:
PCIEx16
anything - unused
anything - unused
PCIEx16
anything - unused
anything - unused
PCIEx16
I run 3x5970s (6 GPU) that way just fine. Granted this is w/ no case. I simply have the MB mounted to an ATX MB tray (w/ expansion slots to support the video cards).
~2300 MH/s per rig and 870W @ the wall.
You just need a MB w/ a slot configuration:
PCIEx16
anything - unused
anything - unused
PCIEx16
anything - unused
anything - unused
PCIEx16
I run 3x5970s (6 GPU) that way just fine. Granted this is w/ no case. I simply have the MB mounted to an ATX MB tray (w/ expansion slots to support the video cards).
~2300 MH/s per rig and 870W @ the wall.
I'm open-minded about open-air. I like the idea of a chassis if it doesn't turn out to add silly expense or inconvenience.
Unfortunately, with 3 or 4 GPU's you'll need a E-AXT, XL-AXT or HPTX. All of which are expensive boards and enclosing them is equally expensive.
You can do an ATX board, but you need PCIe extensions because of the heat generated and it will no longer fit in an off-the-shelf enclosure.
BTW, in response to your PM: All operating systems with available ATI SDK, except for mac (don't know, don't use it), will allow up to 8 GPU's. 5970's are dual GPU's so you are at 6 total now
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Right now my only development system is a MacBook Pro
Really?! What kind of development do you do, web?Quote
...
Open air rigs are still portable, I move mine around fairly frequently.
I'm open-minded about open-air. I like the idea of a chassis if it doesn't turn out to add silly expense or inconvenience. Open air rigs are still portable, I move mine around fairly frequently.
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Right now my only development system is a MacBook Pro
Really?! What kind of development do you do, web?Quote
You move out of the dc or you have some at home too?
Open air rigs are still portable, I move mine around fairly frequently. Run an open-air rig. No case. Those 5970s get way hot when they're sitting right next to each other in a case. Plus it's cheaper to go caseless
Open is OK, but I'd prefer a chassis so the rig can be moved as a unit. Build em yourself.You got a copy of XP or Win7??? You can even use a flash drive instead of a hardrive if you can figure out Linux(I have no clue about Linux myself 
).
System software is still an open question. I am going to want to get into the GPU software at a low level just to make sure I won't have any ideas to speed it up, so I think I'm going to want to run AMD's SDK, which is either Win7 or Linux. Right now my only development system is a MacBook Pro on which I run, in addition to Mac OS, Win7 via virtualization. I could also run Linux the same way, but am not currently.).Quote
You can either build 3 small rigs for about $140 each,dual core AMD cpu($50),mini atx mobo($30),no less than a 600watt powersupply($40)for single 5970,1 gig DDR3 ram($20),use an old hardrive you got laying around.
Or 1 large rig for about $600,1500 watt powersupply for 3 5970's($275 or so),3 slot PCIE 16x mobo($250),same cpu & ram.
Definitely one rig containing the three cards. Based on what I've read and seen on these Forums I'm pretty sure that can be done by separating the cards (with empty slots between) in a closed case with lots of airflow. But I don't require a closed case. Or 1 large rig for about $600,1500 watt powersupply for 3 5970's($275 or so),3 slot PCIE 16x mobo($250),same cpu & ram.
I would recommend you do something like this:
These are a couple of rigs I have running. PM me if you would like some details.
These are a couple of rigs I have running. PM me if you would like some details.
You move out of the dc or you have some at home too?
I would recommend you do something like this:
These are a couple of rigs I have running. PM me if you would like some details.
These are a couple of rigs I have running. PM me if you would like some details.
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