- Sep 25, 2009
- 22
- 0
- 18,510
Hi. I'm having a problem with running two GTX 780s in SLI. Everything worked well for a few days but last night, in the middle of Fallout 4, my PC turned off and wouldn't turn back on - no power at all, even the fans wouldn't spin up.
After some testing, I unplugged the power cables to card #2 (in the lower slot), unplugged and replugged the power cable to the motherboard, and lo and behold my PC turns back on and I can game just fine - albeit with one graphics card.
If I plug the power cables to card #2 back in, the PC won't power on. When i hit the power button I hear a slight click, the fans nudge just a bit, and then nothing. Even after unplugging power to graphics card #2 I still can't power on the PC until I unplug and replug the motherboard's power cable.
I did a little research on PSU amperage. According to this link my graphics cards need 42A on a single +12V rail. According to the spec sheet for my PSU, the max output on the +12V rail is 83.3A. Does it sound like my two graphics cards added together are hitting the amperage ceiling of my PSU? If so, that's kind of a bummer since it was marketed as SLI compliant.
Oh, and whenever I plug card #2 into my other PC it works just fine and plays games as usual. Unfortunately, I can't test SLI in that PC because it's a mini-ITX and only has a 500W PSU.
Here's my PC:
CPU: Intel Core i7-4770K 3.5GHz Quad-Core Processor
CPU Cooler: Corsair H80i 77.0 CFM Liquid CPU Cooler
Motherboard: Asus Maximus VI Formula ATX LGA1150 Motherboard
Memory: G.Skill Sniper Series 8GB (2 x 4GB) DDR3-2133 Memory
Memory: G.Skill Sniper Series 8GB (2 x 4GB) DDR3-2133 Memory
Storage: Samsung 840 Series 500GB 2.5" Solid State Drive
Storage: Hitachi Deskstar NAS 3TB 3.5" 7200RPM Internal Hard Drive
Storage: Hitachi Deskstar NAS 3TB 3.5" 7200RPM Internal Hard Drive
Video Card: MSI GeForce GTX 780 3GB TWIN FROZR Video Card (2-Way SLI)
Video Card: MSI GeForce GTX 780 3GB TWIN FROZR Video Card (2-Way SLI)
Case: Fractal Design Define R4 Blackout with Window ATX Mid Tower Case
Power Supply: EVGA SuperNOVA G2 1000W 80+ Gold Certified Fully-Modular ATX Power Supply
UPS: CyberPower 1500PFCLCD
Optical Drive: Lite-On iHAS124-14 DVD/CD Writer
Operating System: Microsoft Windows 8.1 OEM 64-bit
Monitor: Yamakasi DS270 IPS SE 27.0" 2560x1440 60Hz Monitor
Keyboard: Cooler Master Storm QuickFire Ultimate Wired Gaming Keyboard
Headphones: Corsair VOID 7.1 Channel Headset
Generated by PCPartPicker 2017-04-09 21:55 EDT-0400
Sorry for the length of the post. I'd be very grateful if anyone could offer some advice or guidance.
After some testing, I unplugged the power cables to card #2 (in the lower slot), unplugged and replugged the power cable to the motherboard, and lo and behold my PC turns back on and I can game just fine - albeit with one graphics card.
If I plug the power cables to card #2 back in, the PC won't power on. When i hit the power button I hear a slight click, the fans nudge just a bit, and then nothing. Even after unplugging power to graphics card #2 I still can't power on the PC until I unplug and replug the motherboard's power cable.
I did a little research on PSU amperage. According to this link my graphics cards need 42A on a single +12V rail. According to the spec sheet for my PSU, the max output on the +12V rail is 83.3A. Does it sound like my two graphics cards added together are hitting the amperage ceiling of my PSU? If so, that's kind of a bummer since it was marketed as SLI compliant.
Oh, and whenever I plug card #2 into my other PC it works just fine and plays games as usual. Unfortunately, I can't test SLI in that PC because it's a mini-ITX and only has a 500W PSU.
Here's my PC:
CPU: Intel Core i7-4770K 3.5GHz Quad-Core Processor
CPU Cooler: Corsair H80i 77.0 CFM Liquid CPU Cooler
Motherboard: Asus Maximus VI Formula ATX LGA1150 Motherboard
Memory: G.Skill Sniper Series 8GB (2 x 4GB) DDR3-2133 Memory
Memory: G.Skill Sniper Series 8GB (2 x 4GB) DDR3-2133 Memory
Storage: Samsung 840 Series 500GB 2.5" Solid State Drive
Storage: Hitachi Deskstar NAS 3TB 3.5" 7200RPM Internal Hard Drive
Storage: Hitachi Deskstar NAS 3TB 3.5" 7200RPM Internal Hard Drive
Video Card: MSI GeForce GTX 780 3GB TWIN FROZR Video Card (2-Way SLI)
Video Card: MSI GeForce GTX 780 3GB TWIN FROZR Video Card (2-Way SLI)
Case: Fractal Design Define R4 Blackout with Window ATX Mid Tower Case
Power Supply: EVGA SuperNOVA G2 1000W 80+ Gold Certified Fully-Modular ATX Power Supply
UPS: CyberPower 1500PFCLCD
Optical Drive: Lite-On iHAS124-14 DVD/CD Writer
Operating System: Microsoft Windows 8.1 OEM 64-bit
Monitor: Yamakasi DS270 IPS SE 27.0" 2560x1440 60Hz Monitor
Keyboard: Cooler Master Storm QuickFire Ultimate Wired Gaming Keyboard
Headphones: Corsair VOID 7.1 Channel Headset
Generated by PCPartPicker 2017-04-09 21:55 EDT-0400
Sorry for the length of the post. I'd be very grateful if anyone could offer some advice or guidance.
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