PSU cables: is it possible/safe to power a 8pin GPU with 2X 4pin CPU cable ?

[Iamtutut]

Hello,


I've used all available cables from my 750W modular (super flower leadex) PSU to power my GPUs and risers (6pin intake, no molex). I have a spare 2X 4pin CPU cable (9pin "modular" inpout). Can I safely use it to feed a 8pin PCI-E GPU ?

Thanks

[1714944523]

1714944523

[Vann]

The pinout on the CPU aux power connector and PCI-E connectors are different. There are adapter cables that convert a 8-PIN EPS connector to a 8-pin PCI-E connector, but you need to be careful because the rail/cable on the PSU CPU connector may not be able to handle a high load. Another option is to use a dual ATX adapter cable to daisy chain another PSU so you have all the connectors you need and don't overload the PSU.



https://www.aliexpress.com/item/PSU-Power-Supply-24-pin-ATX-Motherboard-Mainboard-Adapter-Connector-Cable-Dual-l/32822971973.html?

[theodrim]

but you need to be careful because the rail/cable on the PSU CPU connector may not be able to handle a high load.

Can you show any psu with separate eps cpu rail and common 12v rail? Didn't heard/see of any with such configuration.

[philipma1957]

but you need to be careful because the rail/cable on the PSU CPU connector may not be able to handle a high load.

Can you show any psu with separate eps cpu rail and common 12v rail? Didn't heard/see of any with such configuration.

they are around  here is one it is old and has six rails.  I would not mine with it.


http://www.tomshardware.com/reviews/computex-day-1-cooling,1618-8.html


there are newer models

[Vann]

but you need to be careful because the rail/cable on the PSU CPU connector may not be able to handle a high load.

Can you show any psu with separate eps cpu rail and common 12v rail? Didn't heard/see of any with such configuration.

By rail I mean the individual connector on the PSU. PSU connector ratings differ between models from the same brand and even different VGA ports on the same PSU. e.g. EVGA specifically says in their G2/P2 manuals the 8-pin with 6-pin pigtail cables should only be used in the last two VGA ports. In addition the cable gauge used for the CPU/SATA/MOLEX ports is usually thinner than the cables used for the PCI-E cables.

[theodrim]

http://www.tomshardware.com/reviews/computex-day-1-cooling,1618-8.html

Can't see mention of model name anywhere, so no solid info can be had from this. Usually even multi-rail psu use save 12v for both cpu and pcie power.

there are newer models

Will be glad to read about specific models.

By rail I mean the individual connector on the PSU.

Gotha, so not separate voltage rail, but only connector, ok.

[Iamtutut]

I still have 2 available outputs to directly plug a 8pin PCI express cable (+ PCI-E powered riser) from the PSU output, but all I can find to buy is a full set of cables, including SATA and molex that I don't need at all.

Thanks for the explanations, my idea was dangerous.