which PSU for my system?

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biostud

Lifer
Feb 27, 2003
19,953
7,049
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Originally posted by: Insomniak
Originally posted by: biostud
the spec sheet on the Tagan PSU states that even though the both 12V lines are 20A, then the combined load must not exceed 30A. And the combined load of 3.3V+5V+12V must not exceed 460W.
Tagan 480W spec. PDF

The seasonic S-12 600W can handle a max of 18A on each 12V rail, but can handle 36A combined.


Yeah, but amps are not additive, so frankly leaving the Tagan as a combined 30A 12v rail is going to be better for current input in most situations that leaving it as two seperate 20A 12v rails, but frankly I just like the flexibility of being able to do either. I'm not going through cable hell trying split up my 12v rails evenly.

Hell, most modern video cards shouldn't even be attached to a 12v rail that's less than 17A, so putting them on one that's 18A is pushing the line in my opinion.

That's the problem with dual rail PSUs these days - they're slim pickins for current for high end graphics, and even worse if you end up going SLI. Just not enough amps, period. Like you said....wattage doesn't matter as much as amperage these days.

Since the S-12 600W is SLI certified (even though it might be more marketing) and it has two PCIe 6-pin connectors, I belive that they have designed the PSU in such a way that the load of the rails is somewhat optimal, no need for a 18A rail powering nothing but the CPU. But it would be interesting to know more about how they split the load.
The splitting of the 12V rails for the ATX 2.0 standard might not seem optimal for the end-user, but it seems like it allows for a little more combined power on the 12V rail.
 

Insomniak

Banned
Sep 11, 2003
4,836
0
0
Originally posted by: biostud
Originally posted by: Insomniak
Originally posted by: biostud
the spec sheet on the Tagan PSU states that even though the both 12V lines are 20A, then the combined load must not exceed 30A. And the combined load of 3.3V+5V+12V must not exceed 460W.
Tagan 480W spec. PDF

The seasonic S-12 600W can handle a max of 18A on each 12V rail, but can handle 36A combined.


Yeah, but amps are not additive, so frankly leaving the Tagan as a combined 30A 12v rail is going to be better for current input in most situations that leaving it as two seperate 20A 12v rails, but frankly I just like the flexibility of being able to do either. I'm not going through cable hell trying split up my 12v rails evenly.

Hell, most modern video cards shouldn't even be attached to a 12v rail that's less than 17A, so putting them on one that's 18A is pushing the line in my opinion.

That's the problem with dual rail PSUs these days - they're slim pickins for current for high end graphics, and even worse if you end up going SLI. Just not enough amps, period. Like you said....wattage doesn't matter as much as amperage these days.

Since the S-12 600W is SLI certified (even though it might be more marketing) and it has two PCIe 6-pin connectors, I belive that they have designed the PSU in such a way that the load of the rails is somewhat optimal, no need for a 18A rail powering nothing but the CPU. But it would be interesting to know more about how they split the load.
The splitting of the 12V rails for the ATX 2.0 standard might not seem optimal for the end-user, but it seems like it allows for a little more combined power on the 12V rail.


Yeah, eventually. It's not impossible to do, it just makes you cable a little more carefully to ensure that everything gets the needed juice. For noobs, it makes a dangerous trap. After they get amperages up a bit more, I think it will cease to be a problem.

It's just to me, creating a high wattage supply based around two medium to low amperage 12v rails is kind of snake-oil, like rating PSU output at very low temperatures. 600W power supplies providing a max of 18A on the 12v rail? Many single rail PSUs in the 400-500W range have well over 20A on the 12v.

It just seems like playing with fire to me...
 

biostud

Lifer
Feb 27, 2003
19,953
7,049
136
Originally posted by: Insomniak

Yeah, eventually. It's not impossible to do, it just makes you cable a little more carefully to ensure that everything gets the needed juice. For noobs, it makes a dangerous trap. After they get amperages up a bit more, I think it will cease to be a problem.

It's just to me, creating a high wattage supply based around two medium to low amperage 12v rails is kind of snake-oil, like rating PSU output at very low temperatures. 600W power supplies providing a max of 18A on the 12v rail? Many single rail PSUs in the 400-500W range have well over 20A on the 12v.

It just seems like playing with fire to me...

To me it seems more of the coliding of wattage specs between ATX 1.xx and 2.xx.
Both used total combined load of all rails (standard specified @ 25C (PC P&C specifying at 50C)) to rate their PSU's (except the cheap units using the peak power :p). They still use use the combined maximum load, but they need dual 12V lines (AFAIK) to live up to the 2.xx standard, why they changed it I have no idea, but a guess would be the power need for the prescott's :p
 

Insomniak

Banned
Sep 11, 2003
4,836
0
0
Originally posted by: biostud
Originally posted by: Insomniak

Yeah, eventually. It's not impossible to do, it just makes you cable a little more carefully to ensure that everything gets the needed juice. For noobs, it makes a dangerous trap. After they get amperages up a bit more, I think it will cease to be a problem.

It's just to me, creating a high wattage supply based around two medium to low amperage 12v rails is kind of snake-oil, like rating PSU output at very low temperatures. 600W power supplies providing a max of 18A on the 12v rail? Many single rail PSUs in the 400-500W range have well over 20A on the 12v.

It just seems like playing with fire to me...

To me it seems more of the coliding of wattage specs between ATX 1.xx and 2.xx.
Both used total combined load of all rails (standard specified @ 25C (PC P&C specifying at 50C)) to rate their PSU's (except the cheap units using the peak power :p). They still use use the combined maximum load, but they need dual 12V lines (AFAIK) to live up to the 2.xx standard, why they changed it I have no idea, but a guess would be the power need for the prescott's :p



lol probably. Intel has enough market prescence to push that kind of stuff around.

The more research I do on this Tagan, the more I like it though. Take a look at the innards of it here. The layout is very neat, the heatsinks are *burly*, much like the "sawtooth" ones you see in Seasonics, and the fan system is push/pull, making sure air keeps flowing well.
 

biostud

Lifer
Feb 27, 2003
19,953
7,049
136
Originally posted by: Insomniak


lol probably. Intel has enough market prescence to push that kind of stuff around.

The more research I do on this Tagan, the more I like it though. Take a look at the innards of it here. The layout is very neat, the heatsinks are *burly*, much like the "sawtooth" ones you see in Seasonics, and the fan system is push/pull, making sure air keeps flowing well.

everyone have their own preferences :)

and just to nit-pick the first tagan link at newegg is the TG-U22, while the review is the TG-U01 :p
 

Insomniak

Banned
Sep 11, 2003
4,836
0
0
Originally posted by: biostud
Originally posted by: Insomniak


lol probably. Intel has enough market prescence to push that kind of stuff around.

The more research I do on this Tagan, the more I like it though. Take a look at the innards of it here. The layout is very neat, the heatsinks are *burly*, much like the "sawtooth" ones you see in Seasonics, and the fan system is push/pull, making sure air keeps flowing well.

everyone have their own preferences :)

and just to nit-pick the first tagan link at newegg is the TG-U22, while the review is the TG-U01 :p


Only difference between them is the seperate 12v rails. Everything else is identical. Several reviews have confirmed this. U22 cracked open has the same fan config, clean setup, and massive sinks as the U01. Also, the 22 is also apparently a revision that runs cooler than the U01.

Every review I've seen has both of them putting a beating on the big names like Antec, Enermax, etc, and looking at the way they're constructed (along with extra features that mark quality, like twisted cabling and an external ground cable), I do believe this is the one for me. Time to order methinks :)

Edit: Pulled the trigger on the U22 from the Egg. Reports to follow in a few days.