Here's another
resource link for the guide.
As for the dual rail section. You may want to amend that section with mention of 3 or more railed PSUs that include (but not limited) PCP&C's
850W four rail PSU.
As for "
cannot be combined!!!". It should be clarified that rails can't be physically combined but amps can be added together when calculating total system power for example, as noted by
nZone/nVidia or the exception of calculating total 12V power going into a video card which
can* receive power from two seperate rails if they're being powered by both PCIe slot
& power connector. The "
cannot be combined!!!" statement can be applied to components powered by a single rail only, like a hard drive, motherboard, fan, etc. Naturally you can't combine or add together the amps of 2 or more rails to calculate a component's power requirement when it's only source of 12V power is from a single 12V rail.
In addition, there's a reason most if not all PSU manufacturers are moving towards producing 2+ rail PSUs. Reasons I've heard for the move are due to safety reasons to hardware (& human life?). If memory serves the higher/faster the current (amp) flow on rail, the more difficult it is to maintain said current & in turn stable operation of devices/components connected to the PSU is compromised.
***Personal opinion***
I assume it's possible to maintain such a high current single rail PSU but at a cost too great and/or not viable for the budgeted PSU market.
***Don't add to guide unless confirmed, if wanting***
As a side benefit, cleaner power is delivered & from what I've heard clean/stable power prolongs hardware life versus hardware failure caused by dirty power (noise) & as mentioned near the very end of the guide, cleaner power = higher OC. Since rails on 2+ rail PSUs are seperate, "dirty" power that affects one rail doesn't affect the other due to isolation.
*12V power via the motherboard's PCIe slot on one rail & 12V power from external power connector on another rail. Note that this doesn't apply to all dual rail PSUs cause some of them have the PCIe power connector & motherboard's PCIe slot on the same 12V rail.
For the modular section, I remember somewhere some source (reliable?) mentioned modular PSUs not being as reliable in delivering power as non-modular PSUs according to PSU manufacturers. Until someone else can confirm this claim, I wouldn't add it into the guide just yet, if ever.
**Shameless Plug***
My Personal PSU suggestion is
this one cause it's the one I own (for good reason).
***Shameless Plug***
EDIT: For plug