Quote from: MrTeal on January 09, 2015, 04:06:52 PM

Quote from: visdude on January 09, 2015, 08:23:36 AM

Fair enough and in that case, I could also contend that since the BFL days, I was able to purchase Corsair CX500s 80 Plus Bronze PSUs at the Egg at a final cost of as low as $9.99 ($39.99 listed sale price minus $20 rebate minus $10 instant promo code discount) and in turn, used those rebate cards to acquire more CX500s at virtually zero out-of-pocket cost. They have powered BFL, Cube, S1 and currently, S3 miners without missing a beat. My point is that we really can't mix in discounts, rebates, refurbished units, resale price, etc. and expect to have a controlled comparison (hence the last sentence of my last post). I think the most sensible way to approach such comparison in order to have a modicum of control with such a variety of complicating factors is to compare the list price of a brand-new Bronze and a brand-new Gold PSU (not refurbs and excluding complex factors such as discounts, rebates, resale value, etc.) with identical/similar wattage rating within a brand as prices vary extensively across brands of identical/similar units.

Since this is an S5 thread, let's narrow it down to the 750W PSUs. The following is a link to a comparison chart at the Egg with a sampling of five 750W Bronze and Gold PSUs ranging from the cheapest Bronze (Logisys @ $64.99) to the mid-higher end Gold (Seasonic @ $129.99). Note that there are more Gold PSUs between $129.99 and $199.90 which makes the average price difference to be way more than just $40 across different brands. But let's focus on the "within a brand" comparison which is between the Corsair CX750 Bronze @ $84.99 and the Corsair RM750 Gold @ $119.99 -- a difference of $35. That's almost $40:

Egg comparison chart of five 750W Bronze/Gold PSUs

In the end, it's how one justifies it. I think it's more like a choice of either enjoying the savings now or enjoying it later when the price difference will have been recouped over a year or two later.

I'd nuke the Logisys from the list. That's why I excluded some PSUs from my search; I don't want to deal with cable issues. The Logisys only has two PCIe cables, and trying to pull 20A+ through each connector on a PSU designed to pinch pennies is a recipe for disaster. On the S1 it was easy because you could just chop the end off a 4 or 8 pin EPS cable, but it's not so easy anymore.
Also, I'm not sure why you included the cheap Logisys but excluded Rosewill, but the Rosewill Capstone 750W is extremely well rated. It's only $80 for the non-modular version, which is cheaper than all the ones you had listed except the Thermal take, which was only $5 cheaper.

Just trying to stay within brands is a little silly though. For instance, Antec has 7 PSUs between 750W and 900W, and the Gold is the cheapest.
Antec
ThermalTake has 9 in that range, and it is a $20 to move from a Bronze to a Gold PSU (plus you get a 140mm fan and modular cables)
ThermalTake
Rosewill (11 in the 750W-900W range) is a $10 difference
Rosewill
Seasonic - $10 difference
EVGA - $25 difference

Even Corsair is only a $25 difference between the cheapest Bronze and the cheapest Gold (CSM), along with all the other benefits you get like modular cables.

I would definitely agree with that you can pick up cheap units if you're only looking at a couple, though that pertains to better rated ones as well. Really, I don't disagree with most of what you're saying, I just disagree that it will cost as much as you suggested to move to Gold from Bronze, or that it would take ~2 years to recoup the difference in most cases. Given an average cost to move up to gold at ~$20, if you're pulling 600W at an efficiency difference of just ~3% (most Bronze exceed spec by more than most Gold), you're looking at 18W which is a 385 day payback on power. Worth it IMO to get other benefits you often see in a better PSU like modular cables and especially moving away from group regulated designs like many Bronze PSUs are.

Like I said, it's ultimately a matter of how one justifies it. We can debate to eternity and still would not be able to come up with a definitive conclusion that we could both agree on as there are a variety of factors that are difficult if not impossible to accurately and consistently quantify. In other words, it is a very relative and subjective topic. At least, I attempted to have some sort of controlled comparison by isolating complicating factors to the best of my ability/knowledge and providing numbers/computation. That's all we can do in this matter. If you're happy with the justification of your PSU choice and I'm happy with mine, that should be good enough.

Detailed PSU 80 Plus certification results here:

http://www.plugloadsolutions.com/80PlusPowerSupplies.aspx#