Corsair has been the salvation of the studio after years of using some grossly underpowered power supplies. Today, however some changes in motherboards have caused some concern with power supply designs. The old TX850V2 was used long ago with the Carbide 300R machine.
The MSI X470 Gaming Plus and MSI X570-A PRO both have EPS12V and ATX12V power connectors over and above the 2×12 connector. So using a single video card with dual 8-pin connectors some lower capacity power supply units lack enough connectors to handle it.
Looking at the RM550x it is clear that while there is enough 12V current, it lacks enough connectors on the output panel. The RM650x has three 12V power cable, the RM750x has four 12V cables, the RM850x has five 12V cables and the RM1000x has six 12V cables.
The old GTX 260 SLI was still underpowered for 1920×1080 gaming while today the RX 480 can play games at 3840×2160.
The OCZGXS850 uses 2 PCIe connectors on its cables. This is also seen with the Corsair cables that came with the HX1000i. For cards with dual 6-pin connector this is not a problem. Dual 8-pin connectors may be too demanding necessitating more 12V connections.
SLI class motherboards generally were underpowered before the EPS12V cable became common. The 990FX motherboard uses one EPS12V which was more successful using dual video cards.
The MSI X470 and MSI X570 motherboards use one ATX12V and one EPS12V CPU power cable. On the MSI X570-A PRO, the primary x16 slot is directly CPU connected while the remaining slots are handled by the X570 PCH. Even the 105W processors do not load the regulators appreciably. The extra 12V current is primarily for the USB-C and the peripheral slots.
With AMD AM4 motherboards, the ATX12V cable is generally safe to be disconnected. Some AMD Threadripper boards have three EPS12V cable requirements necessitating 1600W power supplies to support dual video cards etc.
The HX1000i that is the primary PSU in use has an abundance of cable options but it lacks dual EPS12V cables. Extra cables are easily available from Corsair. Cables are also commonly offered on eBay. An extra EPS12V cable is $4 from Corsair so grabbing a couple extra makes sense given power trends.
The Sapphire RX 480 8GB originally came with a 6-pin PCIe cable connector. Additional power was drawn from the slot. Sapphire used an 8-pin connector to relive the motherboard from the heavy power load. The factory overclocked Sapphire RX 480 is nominally a 150W video card.
The Sapphire RX Fury requires dual 8-pin PCIe cables. The Sapphire RX Fury nominally is a 300W video card which needs a 650W power supply to have enough slack for gaming demands.
Given the brutal power demands of enthusiast class gaming cards. The needs for a high capacity PSU becomes obvious. While the Corsair HX1000i is overkill, the features it offers are worthy.
USB 4.0 AND TYPE-C
The upswing in USB 4.0 is moving to typc-C with as much as 100W of charging power will pressure motherboard designs to be better positioned to support the new standards. For this reason I can envision socket AM5 motherboard needing a pair of EPS12V to support USB 4.0 which needs so much more power for devices.
Corsair offers extra cables at very low cost; all types and styles are available. Alternate color cables are also available for custom setups.