Dropping the "core clock" to below 1200 mHz suggested by an earlier poster will reduce the voltage drawn by each card, without changing the "power limit" or "core voltage."  It may not be necessary to alter the latter two.

Other than sending Nicehash payments to an external wallet, is there any way to alter the payment schedule? 

Rather than getting paid every day with small payments, I'd like to get paid only when my unpaid mining balance exceeds .2 bitcoin.  Anyone know how to set that?  Fewer payments make accounting easier.

Thanks.

It sounds like English might not be your primary language, but I'll try to understand.
1) You shouldn't have any memory errors.  4 GB is the standard amount of RAM in a typical rig. Mining rigs require a minimal amount of memory.  You might even get away with 2 gigs on a Linux-based machine.  Mining rigs memory should be just enough to run the chosen os smoothly during setup.
2)Each riser might require a watt or so overhead in addition to supplying power to the card.  It best not to power more than two risers from a single string of cables.  SATA only provides 55 watts and it is possible for a card to draw up to 75 watts, so Molex and PCIE power is usually better than SATA for power to risers.
3) My most stable rig has 6 gtx 1050 ti's on an Onda D1800.  It is a board that supports six cards, and it doesn't need risers.  My miners with risers are less stable.
4) It sounds like you are describing the BIOS mod to RX-470, 480, 570, 580.  I think what you are stating is true for the 4 GB models. 

Generally, if you have no GPU's, you plug the monitor into the "video out" of the motherboard.  Once you add a GPU, even if it is on a riser, you plug into the GPU.

Components:

GPU:
5x Sapphire Pulse RX 580 8 GB
1x Sapphire Nitro RX 580 8 GB

Board: Asrock H85 BTC pro R2.0

Processor: Xeon E3-1220L

Memory: 4 GB Hynix PC3-12800 DDR3

Risers: VICTONY 6-Pack PCI-E Riser 1x to 16x

Fan: Rosewill RCX-Z90-AL

PSU: Thermaltake Toughpower 1500W 80+ Gold

SSD: Kingspec 90 GB

OS: Windows 10

I'm running the Pulse RX 580's at core: ~1440 MHz, and memory ~2150 MHz--no overvolting.  The Nitro is a slight bit higher, 1462/2196.

I'm running straight Ethash.  I'd like to do dual mining, but I'm thinking my power supply won't be able to handle it.

I've heard that such a system should run 1000 to 1200 watts.  I threw this system on an electricity usage meter and this system is running consistently above 1400 Watts.  Does this sound right to you all?

Thanks for your help.  It actually is a nice little mining rig on the Onda board, and it is hashing away right now.  I liked not having to deal with risers on this build.

I had originally ordered desktop memory myself.  Fortunately, I had one piece of laptop memory sitting in my desk drawer from an old computer that died.  I stuck it in the DIMM slot of the motherboard and it worked.

Сначала я познакомился с Богом. Религия объясняет мою встречу с Богом.

I've already purchased two 750 watt gold power supplies, the Onda board, an Asus 6-port motherboard, and two copies of Windows 10.  Your suggestion is a good one if I build another, though I suppose I'd have to switch to Linux to avoid the GPU limit.
Heh.  These boards don't come with manuals.  I supplied the three SATA inputs with power, but the three Molex connectors are labeled "POUT."  I thought that meant "power out."  Thanks.  I'll try that.

I ordered 12 GTX 1050ti's a couple weeks ago, and 6 of them arrived.  They are a bit different than what I have used in the past.  They have no 6-pin or 8-pin power, so they get all their power from the PCIE slots themselves.

I have a few concerns how to use them in a mining rig.

First, I have an Onda D1800 bitcoin mining board.  That is one of those boards that has 6 full length PCIE slots spaced far apart enough for a card to fit in each slot.  I was able to boot with one card.  Then I tried to boot it up with 6 GPU's and saw only one fan spinning.  I didn't get any video.  I'm concerned because these cards can draw up to 75 watts and 6 of them might be too much for the motherboard.

I'm also concerned about moving them to another motherboard, such as the ASUS H81 bitcoin pro, and using risers.  SATA only supplies 55 watts of power to risers, and these cards may demand more.  I suppose I could undervolt them.

Does anyone have experience in making these cards work? 
 

I just wanted to let everyone know that Nanopool was making deposits for .01 Zec each time my miner earned that amount.  I did have to reset my Jaxx cache to see the funds.

I've been mining Zcash with a couple of gaming computers for seven days at a rate of 600 Sols/s on Nanopool.  I have the Nanopool app installed.  The "Balance" on the app begins at 0 and increases to about 0.01 Zcash and then resets itself 0 over and over again.  So far, my Jaxx wallet shows no transactions.  Anyone have an idea how long it takes for transactions to begin showing up in my wallet?