Please critique this mining rig build

[jake262144]

The LZP-1000 is a superb power supply.
It's able to give you 77 83 amps in the 12 volt rails.

With those GPUs you could easily get away with a smaller PSU.

With this PSU he can add another GPU later on without hassle and additional expenses.

[Nyte]

With those GPUs you could easily get away with a smaller PSU.  750-850 watts would be more than enough.  Also, you could save money by going with a different motherboard.  For 3 GPUs, you could get a $75 motherboard and a pci-e 1x->16x cable if it only had 2 pci-e 16x slots.  That would probably knock $175 off the cost of your rig and wouldn't have any negative effect on your hash speed.

I actually have 4 of those 5870 cards, but I thought I read somewhere that things get a little crazy when you add the 4th card. But that said, I do have 4 cards I can use.

Also, should I be factoring in the cost of PCIe extension cables?

[DeathAndTaxes]

I use that MSI motherboard.  It is somewhat expensive but rock solid, and allows up to 3x5970 without expanders.  

I agree the PSU is likely oversized.  My guess is that mining 3x5870 don't pull more than 650W DC (remember PSU are rated in DC, AC at the wall will be about 10% higher).  So 850W is probably fine.  Nothing wrong going with a larger PSU expect you may be paying for power you don't need.  

If this is a dedicated mining rig I would drop the SSD unless you just enjoy wasting money and power. It will provide absolutely no benefit.  If you boot from USB drive you can turn off entire SATA subsystem in BIOS and save a couple watts (while you are there turn off USB3, onboard sounds, EIDE, etc).

[sgravina]

I still think the SSD is worth it.  Labor saved is worth a lot.  But, I have 10 rigs.  If you have one then the amount of maintenance you need to do is not that much.  Then again I started with only one computer, you may end up with more.

I would get the MSI because you can expand it to run 6 cards.  I run 4 5870 cards on mine.  It burns 812 watts, 164 watts per card and 166 watts for the rest.   So if you want to go to 4 cards get at least a 1000 Watt power supply.  I went with Antec, Corsair,  and Theraltake all 90% gold.  I don't think you will make back the price difference (I haven't figured that out so I don't really know) but I'm very concerned about reliability.  Things break and you want to minimize downtime.  I figured that higher rated power supplies would be more reliable.  Even still I did have to send one back for a replacement.

With that rig I get 406 MH/(card sec), 1.625 GH/sec total. I run cgminer at 900 MHz gpu, 160 MHz memory per card.

Sam

[jamesg]

FWTW, I run 30Gh with the Asrock boards and have nothing but good things to say about them. I run 5x6950, 5x5850, 5x5870 and 5x5830 without any issues.

I also have the following items if you would like to buy them from me for bitcoins. These are extras left over from my build out.

- ASRock 970, same as I linked to.
- Sempron CPU
- Sticks of memory
- Extenders

PM me if you are interested.

All of the equipment is new and I would sell it for BTC. rjk bought some of this stuff from me and is all up and running. This would help get your costs down more.

[jake262144]

I still think the SSD is worth it.  Labor saved is worth a lot.

Care to elaborate, Sam?
There is no difference whether you use an SSD of a usb flash drive. Linux sees them both as /dev/sda.
Install your favorite distro, set up miners, and test the rig. If you're setting up multiple machines just clone the newly configured OS using dd and you're good to go with minimal effort.
Any quality USB3 flash drive will give you decent bootup speed. Adata N005 (which I value for its high transfer rates) is 30-something dollars.
How can one justify spending the extra cash for SSD drives?

[Fiyasko]

I still think the SSD is worth it.  Labor saved is worth a lot.

Care to elaborate, Sam?
There is no difference whether you use an SSD of a usb flash drive. Linux sees them both as /dev/sda.
Install your favorite distro, set up miners, and test the rig. If you're setting up multiple machines just clone the newly configured OS using dd and you're good to go with minimal effort.
Any quality USB3 flash drive will give you decent bootup speed. Adata N005 (which I value for its high transfer rates) is 30-something dollars.
How can one justify spending the extra cash for SSD drives?

Well. I payed $80 to make my computer boot in 10seconds (win7 from "loading" to fully ready to gameout"
And that $80 also turned my BF3 loading time into 15secs, When it used to be One min or more just to load a fking map.
SSD's are for Gamers, And people doing REDICULOS amouunts of data transfers.

Otherwise, there is no jusificaton, Just get some shitty 20GB hdd

[sgravina]

I take back what I said about SSDs.

I just burned out a disk on one of my rigs last night and I realized that most of my disks are 20 MByte laptop drives that I got from microcenter for less than $20.  I have some SSDs which came with a computer I bought off of craigslist.  The SSDs are fast but not much faster than the laptop drives.

You can see that I've tried to build with inexpensive parts.

My main point is that using a USB drive major annoyance.  They take many times longer to boot than a hard disk.  Since I started with them I have a few as backups.  My rig with the burned disk is running off of a USB now and it takes over 2 minutes for it to boot up.

Sam

[DeathAndTaxes]

My main point is that using a USB drive major annoyance.  They take many times longer to boot than a hard disk.  Since I started with them I have a few as backups.  My rig with the burned disk is running off of a USB now and it takes over 2 minutes for it to boot up.

Then you are doing something horribly wrong.  My rigs use el cheapo USB drives and don't take more than 30 seconds to boot.  With Linux I have found shutting off all the "junk" (floppy drive controller, EIDE controller, SATA RAID controller, onboard sounds, serial port) in BIOS greatly improves boot times.

I think once when I was diagnosing a slow Linux live boot I found out of the 3 minutes it took to boot about 2:15 was trying to detect floppy drive.