Four 5970's on MSI 890FX | Bitcointalksearch.org

jjiimm_64

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Quote from: DeathAndTaxes on November 26, 2011, 10:16:35 AM

Quote from: jjshabadoo on November 26, 2011, 02:49:02 AM

Why mention AC and DC. I'm not very educated about usage. Is DC more relevant than AC when calculating total power usage for a PSU or calculating electricity consumption?

PSU is rated in DC watts. No PSU is 100% efficient so the AC load (what is measured at the wall) will be higher. You want the DC load to be about 60% to 80% of PSU rating for max efficiency (depends on the model some provide an efficiency curve).

Quote

Why was 3 x 5970 easier to manage? Did you have trouble keeping the rig stable? Or did you not use a custom case/structure? I have a very talented partner who is great working with metal and will be building us a custom metal frame to hold our mobo, psu and gpu's.

I went w/ 3 x5970 because it was easier to rack. No need for custom rigs and extenders, and dual power supplies. I just used spare MB trays (w/ expansion slots) and racked em up 3 per MB. 15 total. There is no reason why 4x 5970 won't work you just will need to have custom rigs and extenders and possibly dual PSU.

Quote

I bought the seasonic 750 watt because they are gold certified and only a little over $100 on sale at newegg right now.

I know I won't need 1500 watt per rig, but I also know these psu's are more efficient when not at full load. If I break down the rig to sell in the future, I will probably just put one 5970 in a rig and build around it a sweet gaming machine to sell. One 750 watt will be perfect for that.

I would still buy single core semprons. They are dirt cheap and don't use much power. If you want to repurpose the rigs later you could always buy a better gaming CPU.

I have 4 of this EXACT same rig. i bot the sea sonics before the sale. I use 2 psu because with a 1200 watt silverstone, you could not overclock the cards. it would run up to about 745, but higher then that is was unstable. so I go with 2 psus. 820/420 pulls 1190 watts at the wall. These sea sonics are really nice psus.
https://plus.google.com/u/0/photos/112408294399222065988/albums/5658727447810944545

jjshabadoo

hero member

Activity: 535

Merit: 500

I'm using linuxcoin, but not the final, the version just before it. The final version looked too bloated for me and I couldn't get things running correctly in it. I still can't figure out how to get cgminer running, which sucks, but I am a linux noob.

Anyway, I have the catalyst drivers on the version of linuxcoin I'm using which is NOT supposed to have the CPU bug. I run it off a flash drive, etc.

Bottom line is, I have tried to mimmick most of what you have done because it is obvious to me that you know what you are talking about and of course have been very helpful.

My main goal is to as efficient as possible in the hash/watt area so I can mine for a LONG time. Fortunately I have a nice break on my electricity. NO I am not stealing it from a landlord! hahaha

I'm using aggression level 7 in phoenix miner and one GPU keeps going offline after about 12-24 hours. I think it just can't handle the overclock because my temps are great. I get about 58c on one and 63c on the second at max load.

Thanks again for all your help! I plan to be a contributing member to the community for a long time!

I hope my post on your GPU TIM thread was helpful.

coretechs

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Quote from: jjshabadoo on November 26, 2011, 10:45:28 AM

Yeah I have semprons, but I was wondering, do you think they get bottlenecked at all when mining? Seems the machine is less stable due to the cpu load. I've checked into making sure I have the right catalyst drivers, etc. and the cpu still runs at 60-70% load. I know from previous experiences with overclocking, that sometimes the CPU can keep you from reaching higher clocks.

There is a 45 watt dual core AMD that seems it might be better for a more stable and usable machine in terms of being able to navigate while in the linux environment. Once my miners start running, I really can barely move the mouse around or I get a lock up. Just a thought.

I have my cards at 850/300 right now, it might just be that one of my cards really can't handle those clocks.

I also wonder how much people have messed with the aggression settings in phoenix miner. I have mine set at 7 right now, but it seems it gets unstable when higher. I was thinking about downclocking one of my cards and then raising the aggression to see if there's a sweet spot for max, stable hash rate.

It would be nice to start a thread that is pinned to the top of this forum where everyone can put in their hardware set-ups and post settings with hash rates, etc.

850 is probably a bit much on stock voltage unless you have really good cooling. Try 800 and see if it's still unstable.

I have one Win 7 rig with 3x 5970s and after a lot of monitoring and tweaking I found that one of the GPUs does not like to run any higher than 880mhz, no matter how much I undervolt the ram or overvolt the GPU. The temps are fine but it still throttles so it's very likely to be the VRMs running too hot, even at 300mhz. I just run that GPU at 850/1.10v and it's stable and the other 5 GPUs are running at 900mhz/1.15v and sit around 70C. It's getting ~2450mh/s in cgminer running -I 9 and pulls about 1160 watts off the wall with the fans at 100% plus 3 additional external fans and i3 processor.

I am getting ready to wipe the OS and run linux on it. I will probably run 775mhz per core on stock voltage. In the long run, the extra strain of getting a "max hash" just doesn't seem worth the noise/power/longevity of the hardware. Then again, 5970s are $299 new and will only continue to drop in price...

DeathAndTaxes

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Gerald Davis

Mining requires negligble CPU time.

My rigs average <3% cpu usage and that is w/ Semprons downclocked from 2.8GHz to 2.0GHz.

A couple issues:
1) If you have the 100% CPU bug you are going to get at least 100% on one core (thus 50% CPU usage on dual core, 25% on quad core, etc). Having a faster CPU just means wasting even more power.

2) If you are running Windows and all the bloatware that comes w/ it then you may want to use dual or quad core Phenom simply because of the overhead of windows but this has nothing to do w/ mining.

3) If your desktop is lagging that indicates a problem more w/ intensity/aggression. The longer the miner locks up the GPU the longer between intervals that other system resources have access to GPU (like the OS updating desktop). Having more powerful CPU isn't going to improve desktop responsiveness it will just burn off more power doing nothing.

I use cgminer on Linux running on usb key. I have no monitors connected and connecting via/ SSH session.

jjshabadoo

hero member

Activity: 535

Merit: 500

Yeah I have semprons, but I was wondering, do you think they get bottlenecked at all when mining? Seems the machine is less stable due to the cpu load. I've checked into making sure I have the right catalyst drivers, etc. and the cpu still runs at 60-70% load. I know from previous experiences with overclocking, that sometimes the CPU can keep you from reaching higher clocks.

There is a 45 watt dual core AMD that seems it might be better for a more stable and usable machine in terms of being able to navigate while in the linux environment. Once my miners start running, I really can barely move the mouse around or I get a lock up. Just a thought.

I have my cards at 850/300 right now, it might just be that one of my cards really can't handle those clocks.

I also wonder how much people have messed with the aggression settings in phoenix miner. I have mine set at 7 right now, but it seems it gets unstable when higher. I was thinking about downclocking one of my cards and then raising the aggression to see if there's a sweet spot for max, stable hash rate.

It would be nice to start a thread that is pinned to the top of this forum where everyone can put in their hardware set-ups and post settings with hash rates, etc.

DeathAndTaxes

donator

Activity: 1218

Merit: 1079

Gerald Davis

Quote from: jjshabadoo on November 26, 2011, 02:49:02 AM

Why mention AC and DC. I'm not very educated about usage. Is DC more relevant than AC when calculating total power usage for a PSU or calculating electricity consumption?

PSU is rated in DC watts. No PSU is 100% efficient so the AC load (what is measured at the wall) will be higher. You want the DC load to be about 60% to 80% of PSU rating for max efficiency (depends on the model some provide an efficiency curve).

Quote

Why was 3 x 5970 easier to manage? Did you have trouble keeping the rig stable? Or did you not use a custom case/structure? I have a very talented partner who is great working with metal and will be building us a custom metal frame to hold our mobo, psu and gpu's.

I went w/ 3 x5970 because it was easier to rack. No need for custom rigs and extenders, and dual power supplies. I just used spare MB trays (w/ expansion slots) and racked em up 3 per MB. 15 total. There is no reason why 4x 5970 won't work you just will need to have custom rigs and extenders and possibly dual PSU.

Quote

I bought the seasonic 750 watt because they are gold certified and only a little over $100 on sale at newegg right now.

I know I won't need 1500 watt per rig, but I also know these psu's are more efficient when not at full load. If I break down the rig to sell in the future, I will probably just put one 5970 in a rig and build around it a sweet gaming machine to sell. One 750 watt will be perfect for that.

I would still buy single core semprons. They are dirt cheap and don't use much power. If you want to repurpose the rigs later you could always buy a better gaming CPU.

grubles

full member

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mistaken for gribble since 2011

I run 4 x 5970s on an MSI 890FX with dual PSUs, one 600 watt the other 1000 watt.

One 5970 is extended with a PCIE adapter to negate heat gains.

~3 GH/s @ 364 Mh/s per core (8 cores)

jjshabadoo

hero member

Activity: 535

Merit: 500

Why mention AC and DC. I'm not very educated about usage. Is DC more relevant than AC when calculating total power usage for a PSU or calculating electricity consumption?

Why was 3 x 5970 easier to manage? Did you have trouble keeping the rig stable? Or did you not use a custom case/structure? I have a very talented partner who is great working with metal and will be building us a custom metal frame to hold our mobo, psu and gpu's.

I bought the seasonic 750 watt because they are gold certified and only a little over $100 on sale at newegg right now.

I know I won't need 1500 watt per rig, but I also know these psu's are more efficient when not at full load. If I break down the rig to sell in the future, I will probably just put one 5970 in a rig and build around it a sweet gaming machine to sell. One 750 watt will be perfect for that.

DeathAndTaxes

donator

Activity: 1218

Merit: 1079

Gerald Davis

If it is a custom rig you likely don't need dual power supplies. I pull 870W at the wall (800W DC) using 3x 5970, sempron CPU running linux on usb key. 4x5970 is likely 1100W DC (1250W AC at the wall).

I tried 4x5970 and 3x5970. I found 3x5970 easier to manage but either way it is an efficient rig.

jjshabadoo

hero member

Activity: 535

Merit: 500

I know I'll need pci-x16 cable extenders to deal with heat and I will be building a custom case. I plan to use two seasonic 750w and just jump the second one as it will only supply power to two video cards. Anything I am missing here? Any issue with this mother board handling all four cards that anyone knows of? I'm on linux, so eight GPU's won't be an issue.

Thanks. Hoping to hit 6 G/hash soon Wink

Topic: Four 5970's on MSI 890FX (Read 1511 times)