Thanks. It's all in my attached garage. In the winter I have a window vent blowing cool air in. With the door open to the house it keeps the lower half of the home warm all winter. In the summer, the ambient temps of the lower house/garage keeps everything cool and the window vent is reversed to blow the warm air out. There are better ways and I may change it, but this is working for now.

Can anyone guess what car is sleeping for the winter?

Well, when I could get the Stars Wars editions for $1138 (THX 1138 in case the fans missed the price reference), it was worth it. At $1200 for a reference model, not so much. With the Ti's around $920 - $999, the collector edition Titans give a 5% - 7% boost in mining performance with a 15% - 20% better power efficiency over the 1080ti. They definitely run cooler than the Ti's. The advantage was also being able to get so many without waiting because NVidia allowed two per customer of each faction. I could order 4 more the next day and the next, etc. The added advantage is they will always be worth more than a 1080Ti or standard Titan Xp percentage-wise because they are special.  I just wish George Lucas would have named his first movie THX 1038 so Princess Lea would have been in Cell Block 1038 and the price of Titans would have been $100 less.  

The 520 - 545 SOL are on 1080's, not TI's, maybe you misread. I'm running about 70% - 75% power to get those numbers. My small TI rig averages 690 - 720 at 75% and 720 at 80 - 85% depending on the coin mined.  Average temps in the high 50's to low 60's, I don't exceed 65C. 

Well, it's a loaded question and I'll give a loaded answer.  On the XP's, right now I've got the power levels set to about 80%, with RAM at 6000 and GPU core at 1733Mhz-ish. That gives me roughly 720 - 740 SOL/s. But before you scream rippoff, I have a mini rig with a couple 1080TI's that can do the same with mild tweaks... but the Titans use a lot less energy at 80%. It's around 225 watts. The TI's use 275 - 300 watts to get the same result.  Now, I can get 810 -820 SOL/s on the Titans by upping the power to 110% - 120%, but my consumption jumps to 300 watts and I start to get diminished returns. If I had free power it wouldn't matter and I'd leave it at 820 SOL/s.

My 1080's average 510 -540 SOL/s at 65% - 75% power. Interestingly enough, I have two cheapo MSI reference cards in their own separate rig doing 545 SOL/s, beating all my other EVGA and Gigabyte 1080's, I can't explain it.

Total Hashrate is about 20k with what's in the picture.

About $100 - $110 after electric costs if cashing out 100%.

Thanks, ZCash.

4GB is enough. I have 12 Titans on a GA-B250 with only 4GB ram. Tried 8GB and there was zero difference.

Just wanted to share a pic of my rigs in the dark. 18 Titan XP's and 12 1080's in this setup.
Two Gigabyte GA-B250's and one 990fxa-ud3 MB. Running strong.

You are somehow not accurately measuring true power power consumption. The Nano can pull up to 250 watts each under full load. Anandtech measured 327 watts for full system load playing Crysis 3. TDP is not the same as peak, especially when mining. Your Celeron, MB, and HDD can pull 75 watts on mild load easily. That's 575 watts peak for 2 cards and 825 watts with 3. You are underpowered.

I refuse to use Excavator for anything other than Nicehash. I get better results from the latest cudaminer. Plus, I have a theory that all those "benchmarks" that nicehash requires when a mosquito lands on your GPU are giving them free hashes.

I don't think it's your risers, I'm using both types, including the one that's recommended here. Yes, you could have one bad riser, but there is nothing wrong with using SATA or Molex to power them, I have one SATA ribbon powering 4 risers and it's not even warm. The current draw is very low and connecting a PCIE directly into the riser will make you run out of PCIE connectors fast, requiring PCIE splitters for this small rig, when the OP needs two PCIE for each TI already. I think the OP's issue is either the PSU or one bad riser. I'm leaning towards PSU since it was working fine for a week. Jiboo, I don't know what PSU you have, post it with specs. You could have popped or dried a capacitor if your PSU is cheap.  You could try swapping the PSU that powers the MB, I would do that first. I know that 4 TITANs on one of my rigs can crash my Corsair 1200w on full load if it also powers the MB/CPU. Your 1300w sounds like a flake.

I just bought this board and surprisingly got it to work the first time, but I have read many posts and watched many youtube vids and have experience on other difficult boards. I currently have 12 Titan Xp's running on the B250. Here's the key things to make sure are in order to get this to work with NVidia cards you first time (or second), follow this advice to a tee:

1. Download the latest Windows 10 ISO from Microsoft and install a fresh copy.
2. Plug the cards in sequential order and don't skip slots. Only use 4GB ram modules.
3. Do not use any of the molex connectors on the board and only plug the first power supply 24pin into the mb, "A".
4. Make sure you have the latest BIOS and reset it to defaults. There is nothing that needs to be changed if the latest revision.
5. Load windows with the network cable unplugged. Don't update during install, and once Windows is loaded, disable windows updates.
6. With the network cable unplugged, install the latest NVidia drivers from a USB stick. Be patient. Deselect every option on the install, only install the drivers.
7. Reboot. Install Latest MSI Afterburner (Yes it will detect all cards). Reconnect to Internet.
Done.

Finalize: I advise to keep updates disabled and don't exceed 12 or 13 NVidia GPUs, though 106's or AMD can be added. Be sure to turn off sleep/hibernation.

My Setup:  B250, TITAN Xp (x12), i3 7100, two 4GB modules.

It is important to keep Windows off the Internet and disable the Windows update service. During your card setup, if Windows sees the Internet and can update, it will try to pull generic drivers for the GPUs and that's where everything goes wrong.  I played with the BIOS as soon as I fired up and this caused problems in my first 5 minutes. After resetting back to defaults everything fired up, Windows installed, and the driver install was flawless, so keep the BIOS at default values and resist the urge to play with it.

Another very important thing to remember is how to properly connect your PSU's. Use a proper PSU syncing module, the ones that use a SATA or Molex from the master and connect to the 24pin on the slave PSU, $5 on ebay. Do not use the B and C 24 pin connectors on the motherboard, or the molex connectors. And never ever share or cross PSU's to the same GPU. You must use the same PSU to power both the PCIE riser and the GPU 12v. Some people, and even some manufacturers don't understand how a switching PSU works. The bottom line is they can't share rails between each other, the delta during the switching phase can and will eventually burn out the PSU or GPU, or MB. And don't buy those PSU linking hubs from newegg, same problem. I don't know if the B and C channels are properly isolated on the B250 MB, but I do know it's safer not to use them. Your powered risers take care of that so just use the 24pin "A" and CPU power from your host PSU and nothing else.

Another observation I made is that the CPU is taxed quite a bit with this many lanes running. I think some of you out there may be bottlenecked if using a Celeron or other ultra low end CPU. With an i3, all four threads are moving at 25%-50% during mining on this rig using cudaminer, when normally it's less than 10% with 7 cards. Some have complained that the board becomes very slow when exceeding 8 cards. Installing and loading up windows was not slow for me with a 7th gen i3. Finally, use an SSD, it will save you valuable time during reboots and loading.

I hope these tips help save some headaches, time and cash.
Keep Mining.