Help with my builld!

[jrobe121]

To all:

I've been working on my new rig for over a week, literally.  Stats as follows:

Phenom X4 955 black edition
Asus Crosshair Formula IV
2 x 4 GB G skill DDR3 1600
2 x XFX 5850 1GB
1 x Sapphire 5870 2GB
250GB seagate 7200 RPM sata 6 GB/s
Dynamax 850 watt PSU
NZXT zero cool (I'm changing to an Azza case tonight)

For two weeks I had a coolmaster 750 watt power supply and only ran the 5850's.  I easily overclocked to 895 core and 300 memory getting 335-340 Mhash consistantly with temps around 65 C.

This past week I added the 5870 and immediately had issues.  From every review of tripple crossfire on 5870's the most I saw in power use was 600 watts, so I thought 750 would be fine.  Yet even still my PC would shut off within minutes of trying to mine on all 3 without overclocking. 

So I upgraded to the 850 watt PSU.  I can mine on all 3 for at 870 core on all 3 cards.  Temps are 55 on the 5870, then 85 and 65 on the 5850's.  The Azza case will give MUCH better airflow so hopefully temps will get under control.

MY PROBLEM:

When I clock the 5870 to 900 core and 350 mem, along with just one of the 5850's mining at 880 core 350 mem the computer shuts off like the PSU is insufficient.  If I clock the mem down to 300 I can't even start mining as the computer freezes.

ANY HELP?  I use afterburner and trixx FYI.

[1714907829]

1714907829

[Atlanta.SteveA]

Try running a higher memory clock. I have a PowerColor 5870 that doesn't like to have the memory run under 800. I have a couple 5830's that have absolutely no issue running with the memory running at 300. Keep an eye on the wattage draw though. An 850 will work, but you generally don't want to push a PSU past 80% of its capacity. Also as the equipment heats up, it will be less efficient and will draw more power. See what you can do to get some more air to that 5850 running at 85C. It would be much better you could drop it by at least 15C. Run it without a case if you need to.

-SteveA

[Reikoku]

I can't find the PSU anywhere, but is that an 850W peak load PSU or 850W constant?

Your 5870 will use about 190W of power, and your 5850s will use about 170W each. Your Phenom will draw around 125W of it's own (not sure why you'd use this, especially if its a dedicated mining rig).

This lot comes to 655W without accounting for case fans, drive, motherboard, other random devices. Ultimately a lot of 850s struggle with this much constant power load.

[Calavera]

I can't find the PSU anywhere, but is that an 850W peak load PSU or 850W constant?

Your 5870 will use about 190W of power, and your 5850s will use about 170W each. Your Phenom will draw around 125W of it's own (not sure why you'd use this, especially if its a dedicated mining rig).

This lot comes to 655W without accounting for case fans, drive, motherboard, other random devices. Ultimately a lot of 850s struggle with this much constant power load.

I was going to question the use of the x4 too.  You could pick up a Sempron 140 for very cheap.  You could also pull one of the RAM modules.  I'm not sure why you upgraded from a Coolermaster 650w to a 750w PSU ... seems like a small upgrade unless you had one lying around.

[jrobe121]

I thought I was pretty technical with everything.  Now I feel a fool!

http://powersuppliesto.blogspot.com/2011/05/azza-psaz-850b14-dynamo-850w-power.html
AZZA PSAZ-850B14 Dynamo 850W

I got this on amazon for just a few dollars more than the cool master.  I upgraded 750 to 850 thinking I was using at the most 600, but as said I am using 650 watts now.  I JUST thought to look into what these 80 plus certifications mean... so my 850 psu really runs at just under 700 watts.  I think the labeling is ridiculous, but who am I to say.

As far as the x4 goes it was only $20 more than a cheaper anthlon so I thought why the hell not.  I am going to underclock the cpu and see if that helps at all.

So I am guessing I just probalby just step up to a 1000 watt psu, Although for the price of one I could just but a cheap used PC and run one of the video cards in that. 

I spent about $1300 building this system, and from doing more research after the fact I found I could have built 3 separate systems and had a 50% increase in Hashing power for cheaper!

[finnthecelt]

I'm no expert but from everything I've read when you crossfire all the cards should be the same. The problem may be adding the 5870 in and of itself. It may not be a power issue at all......

[jrobe121]

You may be right, but from what I understand they only have to be the same 58xx or 57xx or however you want to call it.  And if your MB has the lucid chip you can run whatever in crossfire

[finnthecelt]

Are they running the same driver?

[jrobe121]

Yes I have the most current drivers.

[finnthecelt]

Any progress? Are you going to upgrade the PSU?

[jrobe121]

Well the 850 watt PSU exploded.  The 750 PSU powered 2 of them fine.

I purchased a 1000 watt PSU and it has been running all 3 gpus overclocked for a week solid!  Though thanks to this ridiculous difficulty factor increase this rig I built is not even close to being profitable.

It was worth a shot...

[finnthecelt]

Well the 850 watt PSU exploded.  The 750 PSU powered 2 of them fine.

I purchased a 1000 watt PSU and it has been running all 3 gpus overclocked for a week solid!  Though thanks to this ridiculous difficulty factor increase this rig I built is not even close to being profitable.

It was worth a shot...

You mean right now..... Keep mining and hang on to your coins. That's an option. Do you just have the one rig?

[sakkaku]

Well the 850 watt PSU exploded.  The 750 PSU powered 2 of them fine.

I purchased a 1000 watt PSU and it has been running all 3 gpus overclocked for a week solid!  Though thanks to this ridiculous difficulty factor increase this rig I built is not even close to being profitable.

It was worth a shot...

And that kids is why you buy decent power supplies.

[finnthecelt]

Well the 850 watt PSU exploded.  The 750 PSU powered 2 of them fine.

I purchased a 1000 watt PSU and it has been running all 3 gpus overclocked for a week solid!  Though thanks to this ridiculous difficulty factor increase this rig I built is not even close to being profitable.

It was worth a shot...

And that kids is why you buy decent power supplies.

Right. Two Gpu's, 850W minimum. Three Gpu's, 1200W.

[jrobe121]

Yes I have one rig thats all.

1200 watt is not necessary.  I've been running over a week full power and overclocked on my 1000 watt.  My continuous draw should not be more than 700 watts

[sakkaku]

Well the 850 watt PSU exploded.  The 750 PSU powered 2 of them fine.

I purchased a 1000 watt PSU and it has been running all 3 gpus overclocked for a week solid!  Though thanks to this ridiculous difficulty factor increase this rig I built is not even close to being profitable.

It was worth a shot...

And that kids is why you buy decent power supplies.

Right. Two Gpu's, 850W minimum. Three Gpu's, 1200W.

My rig with a 5850 and a 5870 consume ~550w at full tilt.  That is with multiple hard drives and a power hog of a CPU.  That power supply was just shit because his load should have been somewhere around 750-800w.

Also make sure to run amd cool and quiet and set the affinity for the miners all to one core.  It will underclock 3 of the cores and bump about 50w off your consumption.

[Calavera]

I have a 3x5850/sempron 140 rig that runs at <540 watts.  It runs at about 90W when idle.