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PC Power and Cooling 850SSI Modding
Posted: Sat Mar 22, 2008 1:58 pm
by Sovereign
I have done some research that indicates you cannot plug an EPS 8-pin into a PCI-Express 8-pin socket. Fine. Is there a way to convert the EPS 8-pin into a PCI-E 8-pin (like the 20->24 pin or 24->20 pin) so that I can use the power trapped in that rail? My power supply has a lot of juice that is meant for a second CPU I don't even have.
Here is a review of my power supply. The unit has a 6-pin and EPS 8-pin (both intended for use with dual-CPU systems). However, I have no need for the 8-pin EPS as I have a single CPU and if I'm getting a new graphics card I figure it might help with the power situation as this 850 isn't exactly what I needed (it's meant for servers).
This,
this and
this talk about the PSU's guts, which indeed contain a triple-rail design. Is it possible to "liberate" or "tap" power from one rail and shift it into the graphics card?
Re: PC Power and Cooling 850SSI Modding
Posted: Sat Mar 22, 2008 6:55 pm
by Zertz
Alot, if not most, recent single socket motherboards now use an 8 pin EPS connector instead of the old 4 pin connector. Anyway, that EPS connector has 4 12V wires and 4 ground wires. An 8 pin PCI-E connector has 3 12V and 5 grounds, so the cables aren't compatible.
You could always mod that EPS cable, remove the proper 12V, take a ground from a molex and stick it in the EPS. Then you'd have to reshape the connector so it fits in the PCI-E...
Re: PC Power and Cooling 850SSI Modding
Posted: Sat Mar 22, 2008 7:12 pm
by DMB2000uk
Before I suggest anything I just want to say that this just me musing, and I have no idea if it would be 'safe' to load the PSU like this. To me it seems like it would work, but I don't know how PC Power& Cooling have wired the PSU internally, and so can't say for definite if it will like this mod. Disclaimers aside...
If you were to 'mod' the 6pin 12v EPS instead, if you get a new board, you could still use the 8pin 12v EPS connector (as most new boards are coming with those instead of the 4pin 12v connectors lately).
PCIe 8pin is basically a PCIe 6pin with the extra two connectors being ground (black) wires. You could take the 3 12v (yellow) wires from either the 8pin or 6pin and put them into an 8pin PCIe plug (you could steal one from an adaptor
like this). Wire up the remaining grounds to the black cables on the EPS12v, and if you don't have enough grounds (black) to fall back on, use some from spare molex cables.
There aren't going to be any easy adaptors to swap an EPS 12v to PCIe 8pin as there aren't many people who will have a spare EPS connector on their PSU.
Also, if you were thinking of messing about inside of the PSU to tie the rails together, PCP&C warn you not to as it will stop something working properly or something (i wasn't paying much attention).
Dan
Re: PC Power and Cooling 850SSI Modding
Posted: Sat Mar 22, 2008 8:49 pm
by Zertz
So basically, you can do it, but you don't really want to

Re: PC Power and Cooling 850SSI Modding
Posted: Sun Mar 23, 2008 8:18 am
by martini161
im an electrical engineer so youll just have to trust me on this, DONT DO IT. it simply doesnt uphold the design principals of niether the pcie connector or your power supply
Re: PC Power and Cooling 850SSI Modding
Posted: Mon Mar 24, 2008 7:58 am
by Sovereign
I guess I need a four-pin molex to PCIe 8-pin adapter...