Option 3 IMO...

- Honestly I wouldn't trust even the best 15 year old PSU. Caps are unpredictable.
- Good quality Sata to Molex adapters (Copper AWG 18 if I recall correctly) are almost impossible to find. You'll only find those cheap Chinese ones that cannot handle higher currents.

Maybe searching a little bit on various sites for better deals? Hopefully finding a 5year-ish old Seasonic or FSP PSU that has at least 3 Molex connectors, it shouldn't be impossible...

Tecnically, two molex connector are not required. Also you can significantly tone down card power usage by soft voltmodding.

Pretty sure my BFG 6800OC card beeps like crazy if you don't have both molex connectors plugged in, and it will also beep if not getting enough power from a shoddy PSU. I'm using this very card in a Shuttle XPC with ~ 350W PSU, both molex from different lines, it's fine.

You can't drop voltage down of 6x00 cards using software unless flashing the BIOS.

using software unless flashing the BIOS.

Flashing BIOS = software voltmod.

Three thoughts:
1. Nvidia was aware of bad PSUs so they gave a high recommendation in order not to get bad press for instability from underperforming PSUs. A complete contemporary system sporting the 6800U will draw less than 300W on the wall(!) under 3D gaming load with a quality PSU. You'll be fine with a good modern 350W PSU as long as you aren't running an otherwise crazy setup. Nvidia said so themselves in a revised power estimation.
2. Two seperate cables by themselves won't help much. Usually the drive cables are hooked up on the same voltage rail so there will be the same voltage fluctuations on each cable. The cable is thick enough to supply the required amps, the connector is rated for 11A per pin (132W 12V / 55W 5V). The two connectors merely give the option of connecting the card to two individual power rails on PSUs that support it in case one rail is too weak. The ATX 2.2 specification calls for the 12V2 rail to exclusively power the CPU and the 12V1 rail powering everything else. Even though this requirement was dropped with ATX 2.3 most manufacturers still stick with it when building dual 12V rail PSUs. Hence most PSUs will have all drives and GPUs hooked up to the same 12V rail. Therefore you're fine with a single cable with two connectors or a single connector plus a Y-adaptor. Not hooking up other drives to the same cables/rail seems like another precaution that won't be necessary on modern PSUs that react much faster to load changes than regular early 2000s PSUs.
3. Current PSUs like the BeQuiet! Pure Power 11 500W supply two suitable connectors on different cables plus another cable for drives. It'll be a cable management nightmare though and complete overkill. All you'll ever need is a good 350W PSU with one 4pin connector and a Y-adaptor.
Have fun! 😃

Doornkaat wrote on 2020-02-25, 09:58:

Three thoughts: 1. Nvidia was aware of bad PSUs so they gave a high recommendation in order not to get bad press for instabilit […]
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Three thoughts:
1. Nvidia was aware of bad PSUs so they gave a high recommendation in order not to get bad press for instability from underperforming PSUs. A complete contemporary system sporting the 6800U will draw less than 300W on the wall(!) under 3D gaming load with a quality PSU. You'll be fine with a good modern 350W PSU as long as you aren't running an otherwise crazy setup. Nvidia said so themselves in a revised power estimation.
2. Two seperate cables by themselves won't help much. Usually the drive cables are hooked up on the same voltage rail so there will be the same voltage fluctuations on each cable. The cable is thick enough to supply the required amps, the connector is rated for 11A per pin (132W 12V / 55W 5V). The two connectors merely give the option of connecting the card to two individual power rails on PSUs that support it in case one rail is too weak. The ATX 2.2 specification calls for the 12V2 rail to exclusively power the CPU and the 12V1 rail powering everything else. Even though this requirement was dropped with ATX 2.3 most manufacturers still stick with it when building dual 12V rail PSUs. Hence most PSUs will have all drives and GPUs hooked up to the same 12V rail. Therefore you're fine with a single cable with two connectors or a single connector plus a Y-adaptor. Not hooking up other drives to the same cables/rail seems like another precaution that won't be necessary on modern PSUs that react much faster to load changes than regular early 2000s PSUs.
3. Current PSUs like the BeQuiet! Pure Power 11 500W supply two suitable connectors on different cables plus another cable for drives. It'll be a cable management nightmare though and complete overkill. All you'll ever need is a good 350W PSU with one 4pin connector and a Y-adaptor.
Have fun! 😃

Interesting. If I don't need to use two separate Molex cables to power the card, I have an EVGA 100-W1-0500-KR sitting around that should be more than adequate. I'll fire it up at some point and report back here.

Thanks for the info! This will save me lots of unnecessary hassle and expense.

Glad to be of help! 😀 That single 12V rail 5000W EVGA PSU is more than adequate. 😁
Looking forward to your report!

Doornkaat wrote on 2020-02-26, 10:09:

Glad to be of help! 😀 That single 12V rail 5000W EVGA PSU is more than adequate. 😁
Looking forward to your report!

So many watts! Not quite over 9000 though. 😉

maximus wrote on 2020-02-24, 20:17:

2) Buy a new power supply that can easily power the system and use SATA to Molex converter cables to connect the 6800 Ultra. These converter cables seem to have a reputation for caching fire (seriously), so I'm hesitant to use them with something as power-hungry as a high-end video card.

The adapters that are catching fire are those that don't have the cables well separated with individual pins, mainly the "molded" that look like this

Those that are crimped are perfectly fine since the failure is purely mechanical and not due to electrical reasons, eg.

cde wrote on 2020-02-26, 10:13:

Doornkaat wrote on 2020-02-26, 10:09:

Glad to be of help! 😀 That single 12V rail 5000W EVGA PSU is more than adequate. 😁
Looking forward to your report!

So many watts! Not quite over 9000 though. 😉

5000W? Who said anything about 50000W? I certainly didn't say anything about 500000W! Who needs 5000000W anyway? 😅

I'm slowly standardising my PSU's with Corsair modular ones. The brand doesn't matter so much as long as the cables are interchangeable between different PSU's.
as an example I used the Molex cables from the 750W PUS in my modern rig in my 300W PPro rig