2 PSU 2 GPU dilemma

[LiteralKiteral]

So I've got a fascinating issue, and this will be confusing

I have an i7 7700k clocked at 4.8ghz, 24 GB 2133 RAM, two SATA ssds, one m.2 ssd, and a WD Blue 7200RPM, along with two 1080ti FTW3, one hybrid, one triple fan in SLI. Heres my problem, I previously ran two seperate computers, and in turn now have 2 seperate power supplies to run this monstrosity, 650 Watt thermaltake (master for powering mobo), and a Corsair 550 Watt (slave for just the second video card). I've been having crashing issues, and I suspect it's due to one of the 1080ti's running on a single 8 pin out to 2 8 pins from my 550 watt PSU (the slave psu), I only have 1 8pin pcie power out from the 550 watt and 2 from the 650 watt, all 3 cables having 2 8 pins at the output end, is it in anyway safe to "cross the streams" with the power supplies. I had two ideas as to how to do this. Either take half of one of the 650 psu cables and combine it with half of the 550 watt cable then use the other half of the 550 watt for the other power plug on the second card, and use the rest of the 650 watt connectors on the first card, or split one of the 650 watt cables between the cards and plug in the rest respectively (other 650 watt cable for the second 8 pin of the first card, and a Y cables combo of the 550 watt 8 pin for the second 8 pin of the second card) 

I know this is a mess and hard to follow, but I cant think of a better way to explain it, if you have any questions feel free

I will have the money for a better power supply in a month or so, I just didnt realize that the 550 watt only had one output for 8 pin, and figured I could just do the Frankenstein approach for the time being, so I'm just looking for a temporary solution that wont blow anything up

[seon123]

A 550W with a single PCIe connector and a 650W with two PCIe connectors both sound like they're absolute garbage. You can afford two high end 1080 Tis, but run what I'm assuming is old and/or low end PSUs?

Depending on the PSUs, they could be sending quite different voltages to the GPU. Like 12,2V from one and 11,8 from the other. Not good

[Divide_By_0]

Crazy idea, right, but, get a sufficient power supply for your system instead of risking the life of your -very- expensive components????

Edit: I see it's a money issue, but maybe borrow from someone you trust to not screw you? Better than risking an electrical malfunction and frying parts.

[LiteralKiteral]

Fair note, I am leasing the 1080ti's, that's how I can afford them, but the lease service rarely has other components in stock, and they are both new power supplies, thermaltake 650 watt grandpower gold plus fully modular and the 550 watt is a corsair cx550 bronze plus semi modular, and I'll have the money in a week or two, I was just trying to see if there was some temporary solution for the problem, thanks much for the help, all I could find on this topic was pre 2008 info, so I questioned the accuracy

[Froody129]

9 hours ago, LiteralKiteral said:

Fair note, I am leasing the 1080ti's, that's how I can afford them, but the lease service rarely has other components in stock, and they are both new power supplies, thermaltake 650 watt grandpower gold plus fully modular and the 550 watt is a corsair cx550 bronze plus semi modular, and I'll have the money in a week or two, I was just trying to see if there was some temporary solution for the problem, thanks much for the help, all I could find on this topic was pre 2008 info, so I questioned the accuracy

Why are you leasing graphics cards?

[Stefan Payne]

Oh dear...

That's like asking for trouble or debt...

 

If you can't even afford a good quality PSU for those graphics cards, you shoulodn't have them anyway...

 

 

The two PSU Thing is something more for the Overclocker realm, if you do it wrong, you can kill everything and cause a fire!

[andrewmp6]

The best and only smart idea is to buy one psu that has enough power for your needs.

[LiteralKiteral]

On 8/5/2018 at 3:58 PM, Froody129 said:

Why are you leasing graphics cards?

The first one I got during the height of the mining craze, and by the end of the leas i will have paid less on the lease than buying the card outright at the time, the second one is because I wanted to see how sli performance is as I wanted to do 1180ti sli, so I can buy out the first and resell to help buy an 1180ti when it releases and just upgrade the lease on the second card