- Joined
- Nov 1, 2009
- Location
- Austin, TX
now, the x79 big bang has 2 cpu 8pin eps connectors. should both those eps plugs be on the SAME 12v rail?
my secondary questions: i'm assuming that each 12v rail has its own separate voltage regulator. is that generally correct? (or does it vary by PSU?) if so, would the variances in voltage regulation across two different rails be harmful to the PSU or CPU using two rails to power the same socket? ( i ask because the manual for my toughpower 1200w highly recommends to never power a GPU from two different rails. ie 6 pin connector from 12v3 and 8 pin connector from 12v4. )
i currently have a toughpower 1200w (12v1:20a, 12v2: 20a, 12v3: 45a, 12v4: 45a) and the rail breakdown is: 24pin 12v1, 4+4 pin: 12v2, 8pin eps: 12v2+3, peripheral + floppy +s-ata: 12v1, gpus: 12v3, 12v4. i just today realized the 8 pin connector is split over 12v2 and 12v3. seems like it defeats the purpose of splitting the cpu and gpu onto different rails.
anyhow, i'm watercooling the CPU, and i'm thinking i DON"T want to transfer the 1200w psu to the new rig. i'm thinking of either using a toughpower 1275w (12v1 45a, 12v2 65a) or a platimax 1350w (2 12v rails @20a, 412v rails @ 30a) or a silverstone st1500 or antec hpc 1200.
now the toughpower kinda seems like it would defeat the purpose of multiple rails, but the 2 cpu connectors would be on the same rail. (12v2 gets the GPUs, everything else goes to 12v1)
whereas the platimax 1350w would have 12v1 24pin, 12v2 8pin eps, 12v4/6 has the s-ata and peripherals, 12v3/4/5/6 can have GPUs and/or CPU 8pin eps + 4+4pin atx/eps, which again feels like it defeats the purpose of multiple rails if so many rails can end up sharing volts with all the things i want to separate. BUT, it has paired 8pin/4+4 pin cable i can slap on 12v3/4/5/6 so the cpu would be powered by the same rail. this would mean that the dedicated CPU rail (12v2) would be left unused. i could put all the disk drives and fans and water pump on one rail, and that would leave 2 rails to dedicate to GPUs. (the 1350 has better voltage regulation than the 1200w or 1000w versions, according to johnny guru)
the silverstone and antec PSUs each have 8 rails, SS is 25a each, antec 30a each, but the antec has a LOT of hardwired cables. both of these PSUs have 2 EPS cables, but on different rails. (i'm assuming for dual socket systems). the lower silver/ gold certification wouldn't matter too much as i'd get the better efficiency rating at 50% load, which would be close to what i'd be using with a 3930k (4Ghz or higher) and GTX670 in x2 SLI.
additionally, i am thinking of adding a third GPU for physX, just because i have an extra gtx480 laying around, but i might throw the 480s back into SLI in "earth" once "nevermore" is assembled. the slowly-but-surely project log can be found here: http://www.overclockers.com/forums/showthread.php?t=731313, and don't call me shirley!
my secondary questions: i'm assuming that each 12v rail has its own separate voltage regulator. is that generally correct? (or does it vary by PSU?) if so, would the variances in voltage regulation across two different rails be harmful to the PSU or CPU using two rails to power the same socket? ( i ask because the manual for my toughpower 1200w highly recommends to never power a GPU from two different rails. ie 6 pin connector from 12v3 and 8 pin connector from 12v4. )
i currently have a toughpower 1200w (12v1:20a, 12v2: 20a, 12v3: 45a, 12v4: 45a) and the rail breakdown is: 24pin 12v1, 4+4 pin: 12v2, 8pin eps: 12v2+3, peripheral + floppy +s-ata: 12v1, gpus: 12v3, 12v4. i just today realized the 8 pin connector is split over 12v2 and 12v3. seems like it defeats the purpose of splitting the cpu and gpu onto different rails.
anyhow, i'm watercooling the CPU, and i'm thinking i DON"T want to transfer the 1200w psu to the new rig. i'm thinking of either using a toughpower 1275w (12v1 45a, 12v2 65a) or a platimax 1350w (2 12v rails @20a, 412v rails @ 30a) or a silverstone st1500 or antec hpc 1200.
now the toughpower kinda seems like it would defeat the purpose of multiple rails, but the 2 cpu connectors would be on the same rail. (12v2 gets the GPUs, everything else goes to 12v1)
whereas the platimax 1350w would have 12v1 24pin, 12v2 8pin eps, 12v4/6 has the s-ata and peripherals, 12v3/4/5/6 can have GPUs and/or CPU 8pin eps + 4+4pin atx/eps, which again feels like it defeats the purpose of multiple rails if so many rails can end up sharing volts with all the things i want to separate. BUT, it has paired 8pin/4+4 pin cable i can slap on 12v3/4/5/6 so the cpu would be powered by the same rail. this would mean that the dedicated CPU rail (12v2) would be left unused. i could put all the disk drives and fans and water pump on one rail, and that would leave 2 rails to dedicate to GPUs. (the 1350 has better voltage regulation than the 1200w or 1000w versions, according to johnny guru)
the silverstone and antec PSUs each have 8 rails, SS is 25a each, antec 30a each, but the antec has a LOT of hardwired cables. both of these PSUs have 2 EPS cables, but on different rails. (i'm assuming for dual socket systems). the lower silver/ gold certification wouldn't matter too much as i'd get the better efficiency rating at 50% load, which would be close to what i'd be using with a 3930k (4Ghz or higher) and GTX670 in x2 SLI.
additionally, i am thinking of adding a third GPU for physX, just because i have an extra gtx480 laying around, but i might throw the 480s back into SLI in "earth" once "nevermore" is assembled. the slowly-but-surely project log can be found here: http://www.overclockers.com/forums/showthread.php?t=731313, and don't call me shirley!
