4 ms·
> At these wattages just give it its own mains plug. You might think you're joking, but there are gamer cases with space for two PSUs, and motherboards which c
by cesarb 2y ago
> At these wattages just give it its own mains plug.
You might think you're joking, but there are gamer cases with space for two PSUs, and motherboards which can control a secondary PSU (turning both PSUs on and off together). When using a computer built like that, you have two main plugs, and the second PSU (thus the second mains plug) is usually dedicated to the graphics card(s).
- immibis 2y agoI've done this, without a case, not because I actually used huge amounts of power, but because neither PSU had the right combination of connectors. The second one was turned on with a paperclip, obviously. Turns out graphics cards and hard drives are completely fine with receiving power but no data link. They just sit there (sometimes with fans at max speed by default!) until the rest of the PC comes online.
- 0x457 2y agoYou can also hookup a little thingy that takes sata power on one side and 24 pin on the other. As soon as there is power on sata side, relay switches and second PSU turns on.
- aaronmdjones 2y agoThis may not be fast enough for some add-in cards. It would be better to connect the PS_ON (green) cable from both ATX24 connectors together, so that the motherboard turns on both PSUs simultaneously. This would still have the disadvantage that the PWROK (grey) cable from the second PSU would not be monitored by the motherboard, leaving the machine prone to partial reset quirks during brown-outs. Normally a motherboard will shut down when PWROK is deasserted, and refuse to come out of reset until it returns.
- ryao 2y agoServer systems already work like this for redundancy.
- aaronmdjones 2y agoNo they don't. Server-grade redundant PSUs usually use a CRPS form factor, where individual PSU modules slot into a common multi-module PSU housing known as a PDB (power distribution board). Each module typically outputs only 12V and the PDB manages the down-conversion to 5V, 5VSB, and 3.3V. From there, there is only one set of power cables between the PDB and the system's components including the motherboard and any PCIe add-in cards. Additionally, there is a PMBus cable between the PDB and the motherboard so that the operating system and the motherboard's remote management interface (e.g. IPMI) can monitor the status of each individual module (AC power present, measured power input, measured power output, measured voltage input, measured frequency input, fan speeds, temperature, which module is currently powering the system, etc). PSUs can be removed from the PDB and replaced and reconnected to a source of power without having to shut down the machine or even remove the case lid. You don't even need to slide the machine out of the rack if you can get to the rear. Example: https://www.fspgb.co.uk/_files/ugd/ea9ce5_d90a79af31f84cd59d16e4673d9f72b1.pdf https://www.fspgb.co.uk/_files/ugd/ea9ce5_d90a79af31f84cd59d...
- ryao 2y agoYou can have the machine draw twice the amount from the server PSUs. It kills the redundancy, but it is supposed to work.
- aaronmdjones 2y agoBut that still only happens over one set of power cables, from the PDB. The post you replied to described using a separate PSU with separate component power cables to power specific components. Current sharing in server PSUs is handled by every PSU equally powering all of the components. Edit: For example, in a 3+1 redundant setting, 3 PSUs would be active and contributing toward 1/3 of the total load current each; 1 PSU would be in cold standby, ready to take over if 1 of the others fails or is taken offline.
- Dylan16807 2y agoThe joke actually removes this connector problem though, while a secondary PSU does not.