the ultimate "do i need a 24pin PSU ?" thread

[Zukatah]

Thanks alot for the great read but I still wonder if I could power a 3000+ cpu with a 6600 (non-GT) or a X700 with an Antec TruePower 430. Problem is that I fried my motherboard today and I need a replacement and a new PSU doesn't exactly fit in my budget, especially since I bought the 430 one for a long term usage! So, will it work or I should go out and pony the extra bucks (that's hard to do for a College student)?

Thanks

 

[FastEddie]

Problem is that I fried my motherboard today and I need a replacement and a new PSU doesn't exactly fit in my budget

Are you sure the psu didn't cause the crash & burn? Are you sure the psu is still alive and kicking?

And for jim1976 The 600W Enermax Noisetaker is a contridiction in terms when used with the word "futureproof." And this is one of the most blatantly "slam" marketed psu out there today. Enermax slapped an SLI label on this dual rail unit with specs that are nearly two years old and expect the enthusuiast market to snap them up like lemmings running to the sea. There is nothing that makes this unit Sli special. It has two seperate (low amperage) 12v rails that can't be combined in any way shape or form. You won't get much futureproofing out of 18a per rail.

 

[Algere]

Originally posted by: FastEddie
And for jim1976 The 600W Enermax Noisetaker is a contridiction in terms when used with the word "futureproof." And this is *one of the most blatantly "slam" marketed psu out there today. Enermax slapped an SLI label on this dual rail unit with **specs that are nearly two years old and expect the enthusuiast market to snap them up like lemmings running to the sea. ***There is nothing that makes this unit Sli special. It has two seperate (low amperage) 12v rails that can't be combined in any way shape or form. You won't get much futureproofing out of 18a per rail.

*) I call BS on that one.

**) What specs are you talking about?!? If you're talking about the concept of dual rails in general then you may wanna ask yourself, how old are specs on single 12V rail designs.

***) AFAIK it's labeled "SLI compatible" due to it's dual PCIe native power connectors & IMO can power any SLI system out there within reason. Also most if not all SLI motherboards have 4-pin molex connectors on them & some video cards are designed to receive additional power via the 6-pin PCIe power plug. In both cases, both rails are being drawn (mobo's rail & PCIe/molex's rail) & therefore it is possible to get power [combined] from both 12V rails despite them being physically seperate.

EDIT: "Also most if not all SLI motherboards have 4-pin molex connectors on them" - Assumed it was, later found otherwise (out of curiosity).

 

[FastEddie]

The only thing added to this unit was the pci-e power adapters.

AFAIK it's labeled "SLI compatible" due to it's dual PCIe native power connectors & IMO can power any SLI system out there within reason.

Dual 6800 Ultra's with an oc'd FX55 and it breaks more than a sweat. Now think of dual core processors, and can you still claim it "futureproofs" the technology? It's just a rehash of the unit enermax put out for Intel boards, hence the dual 18a 12v rails. If it was actually designed for SLI, do you actually believe they would engineer both 12v rails at 18a? Next question---how long has Enermax had available a dual 12v rail psu? Answer--quite a bit longer than Sli has been out.

They added two pci-e power connectors and slapped an Sli ready label on it to market the unit to Sli enthusiast.

Lastly--this unit does not combine the two 12v rails, where once the rail is maxed, it can't draw more power from the other rail. Period. There are a few psu's that do allow for combining of both rails, (via a switch), which essentially turn those units into single rail power supplies. But this psu is not one of them.

 

[jim1976]

So a "futureproof" psu will be only a EPS12V or it doesn't worth the extra money?

I don't care for a "SLI compatible or ready" psu but for future dual cpus and hungry gpus

 

[FastEddie]

Originally posted by: jim1976
So a "futureproof" psu will be only a EPS12V or it doesn't worth the extra money?

I don't care for a "SLI compatible or ready" psu but for future dual cpus and hungry gpus

I think the 24-pin (ATX//EPS12v) is here for awhile. A strong single rail unit future-proofs more than low, or mid, power range dual rail psu's. I can't see two 18a 12v rails running dual 6800Ultras and a dual core processor with any kind of stability, let alone with any kind of oc and multiple drives. There are a few power supplies that are under $75.00 that will serve you just fine (they will run dual 6800Ultras and an overclocked FX55, and should run dual core as well).

 

[Googer]

Originally posted by: FastEddie

Originally posted by: jim1976
So a "futureproof" psu will be only a EPS12V or it doesn't worth the extra money?

I don't care for a "SLI compatible or ready" psu but for future dual cpus and hungry gpus

I think the 24-pin (ATX//EPS12v) is here for awhile. A strong single rail unit future-proofs more than low, or mid, power range dual rail psu's. I can't see two 18a 12v rails running dual 6800Ultras and a dual core processor with any kind of stability, let alone with any kind of oc and multiple drives. There are a few power supplies that are under $75.00 that will serve you just fine (they will run dual 6800Ultras and an overclocked FX55, and should run dual core as well).

In the world of technology there is no such thing as future proof. The next best thing is PC Power and Cooling who will upgrade any of their power supplies connections and add the latest connections and what ever else is the newest of the time. So in theory their brand is as close to future proof as it comes.

Call them and find out.

 

[FastEddie]

But hell, $250 for a psu? Theyd have to give me the next five upgrades free to get $250 out of me, especially when a $52 psu has taken everything I could throw at it and have power to spare. Oh, wait a minute, the PCP&C has two pci-e power connectors instead of only one---well, damn, I'll take two of them then I guess. :laugh:

 

[jim1976]

Originally posted by: FastEddie
There are a few power supplies that are under $75.00 that will serve you just fine (they will run dual 6800Ultras and an overclocked FX55, and should run dual core as well).

Well prices are inflated in my country, but any recommendation would be appreciated

 

[FastEddie]

This Athena Power 500W has plenty of power with 28a on a single 12v rail.

The Tagan TG480-U01 runs 28a on a single 12v rail.

This Enermax EG465P-VE FM is a little pricey, but very good.

Just a few. And don't know what you can get your hands on.

 

[jim1976]

Originally posted by: FastEddie
This Athena Power 500W has plenty of power with 28a on a single 12v rail.

The Tagan TG480-U01 runs 28a on a single 12v rail.

This Enermax EG465P-VE FM is a little pricey, but very good.

Just a few. And don't know what you can get your hands on.

Thanks.Well money is an issue, I'm not fond of spending money w/o having a reason to do so, but after my accident I'm willing to spent some extra bucks for a really good one. That's why I asked for a "futureproof" solution, if that thing exists as someone correctly previously mentioned.
28A seems more than enough or extravagant for many ppl today but what about 2morrow? That's why I asked you about the solution of an EPS12V. If I'm to spend a significant amount of money I want to be able to keep it for 2yrs having my upgrades w/o worrying about power consumption.
So ?
(Oh I know PCP&C are great but unavailable here)

 

[FastEddie]

Not knowing what you can get your hands on in Greece, you need to do the searching and posting of specs. Can you get Zippy or Tagan?

 

[Algere]

Originally posted by: FastEddie
Dual 6800 Ultra's with an oc'd FX55 and it breaks more than a sweat.

Proof or assumption?

Originally posted by: FastEddie
Now think of dual core processors, and can you still claim it "futureproofs" the technology?

How far into the future are we talkin' about? Personally I wouldn't know where to calculate how "futureproof" something is, however I can assume/imagine (all we can do) that motherboard manufacturers would implement a molex connector in future motherboards for additional power (as some do now for SLI) if they're aware of ATX12V 2.0's 18A per rail limit, & according to THG (yes, THG!),

"Older ATX (1.0) power supplies with 20-pin main power connector do only have one 12V line. Such a high charge on one line can damage a PSU over the time. New ATX 2.0 PSUs, featuring a 24-pin power connector have two 12V lines, so the load is split to two lines."

That in itself is enough for me not to consider a single rail PSU for high amperage use, let alone other reasons not mentioned.

Originally posted by: FastEddie
It's just a rehash of the unit enermax put out for Intel boards, hence the dual 18a 12v rails.

The 18A rail limit is specifically described in the ATX12V 2.0 specs (pg. 7). So if Enermax wanted to claim ATX12V 2.0 compliant, there ya go.

Originally posted by: FastEddie
If it was actually designed for SLI, do you actually believe they would engineer both 12v rails at 18a? Next question---how long has Enermax had available a dual 12v rail psu? Answer--quite a bit longer than Sli has been out.

Who said/implied dual rails or multi-rails in general was designed for SLI? Heck! single 12V rail PSUs weren't designed/anticipated for SLI either and that's been out way longer than dual rails. IMO single/multi-rails and SLI have nothing to do with each other. How did you come to the conclusion that if a PSU manufacturer slaps a SLI sticker onto a PSU that coincidentally also happens to be dual railed, is the reason they slapped it on there? Did they say it's SLI compatible because it has 2+ 12V rails. If so, I don't remember or know anything about that.

Originally posted by: FastEddie
They added two pci-e power connectors and slapped an Sli ready label on it to market the unit to Sli enthusiast.

Like they did when they added native SATA power connectors & slapped a SATA ready sticker on it? Maybe you'd call it false advertisement if that "SATA ready" PSU couldn't power up 8 SATA drives when a system is already consuming near that PSU's power output limit without all the SATA drives powered.

Originally posted by: FastEddie
Lastly--this unit does not combine the two 12v rails, where once the rail is maxed, it can't draw more power from the other rail. Period.

I wonder who said or implied otherwise. :roll:

 

[FastEddie]

"Futureproof?" Dual core processors is just a matter of a couple months away. That's not asking for much. A known is that they will work using a single rail psu with enough amperage on the 12v rail.

And you make it sound like the dual rail psu is the next best thing to come down the pipe since sliced bread. My point is that the technology has been here awile, and was designed for a totally different animal than what we have with NF4/Sli. The dual rail tech evolved around the Intel architecture, not AMD. But when incorporated into AMD, it was tweaked for multiprocessor/multi-memory bank K7 architecture---not the current K8, which moved most of the current demand to the 12v rail. That particular version of the Enermax hasn't changed the internal components or ratings to take K8 into consideration, let alone the lopsided demands of Sli. So to mearly add a couple of pci-e power connectors and claim that it's the holy grail for NF4/Sli is really stretching it's capabilities to fulfill that demand.

To single rail. That technology hasn't remained static. It's a new implementation, and by no means should be relagated to retirement.

"Older ATX (1.0) power supplies with 20-pin main power connector do only have one 12V line. Such a high charge on one line can damage a PSU over the time. New ATX 2.0 PSUs, featuring a 24-pin power connector have two 12V lines, so the load is split to two lines."

The key here is Older ATX (1.0) power supplies..... The statement is true for that qualifier---older. Not all ATX 2.0 psu's have two 12v lines or seperate rails, and high output/high amperage single rail ATX 2.0 psu's are designed to function properly using a constant power drain in a range of 60-80% of its peak output. No psu should have to run above 90% of its peak output on a continous basis (as in constant use). That is not an element of their design, nor is it an efficient use of the power resource.

 

[imported_ceefka]

What would be enough 12v amperage for a dual core? For AMD http://www.pcper.com/article.php?aid=122 : All the dual core processors will be manufacturered on the 90nm process and will have a maximum power usage of 110w, only 6w higher than the current Athlon 64 FX processors. That would not take much more. As for Intel...???

 

[flexy]

Originally posted by: FastEddie That particular version of the Enermax hasn't changed the internal components or ratings to take K8 into consideration, let alone the lopsided demands of Sli. So to mearly add a couple of pci-e power connectors and claim that it's the holy grail for NF4/Sli is really stretching it's capabilities to fulfill that demand.

I have this same Enermax (the one with 20pin which i modded to 24pin)...i am positive the 24pin version is *identical* to the 20p except that they added the connectors.

I think its kinda emberrassing to read on eg. Antec's website where they try to make people believe that it's only a "half ass" solution because its not REAL ATX2.0 and only an ATX1.3 (one rail) with 24pin.....but to be HONEST...WHO CARES ???

This is an exceptional good PSU which i have running on a heavily overclocked dfi lanparty nf4 board w/ an overclocked, very powerhungry X850XT.

My multimeter shows that eg. the 12V rail NEVER, ever went below 12.1 under load (idle 12.2)...and people can rant hours and hours what a halfa$$ solution it is because "it has no TWO rails and is not real ATX2.0" or Antec can blame their competitors (mainly Enermax) as selling "pseudo ATX2.0" PSUs which (SUPPOSEDLY) are not that good....that's all worthless if i see the EXCELLENT performance of this PSU in real life.

I dont know what else to add,..but i would take this PSU anytime again (but then the one with 24p just to save me the hassle of making a plug myself ) - and it would take a LOT to make me believe that i really need a $250 PC&P or a 600W OCZ or whatever OTHERWISE i would be unable to overclock my memory or CPU or would run into whatever problems.

The ~80 or so i paid a while ago for this PSU are proof that you do NOT need to spend a fortune and still can get high quality...and that you do NOT need ATX2.0 and two rails.

I am running an A64 3500+ w/ 2x 512MB OCZ 3200 EL Plat Rev2 at
9x289 = 2601 (2.5 4 3 7 1T, 1:1) w/ X850XT overclocked - no problems.

 

[Algere]

Originally posted by: FastEddie
"Futureproof?" Dual core processors is just a matter of a couple months away. That's not asking for much. A known is that they will work using a single rail psu with enough amperage on the 12v rail.

Let me rephrase what I meant about dual cores & the future. I'm aware they're coming out soon but you never specified how far into the future you meant. Do you think a 110W/9.2A (max) s939 dual core Athlon 64 will have the same power envelope that a dual core processor on socket M2 would? I can't speak for Intel's dual core but as you've said, it's their PSU spec ...assuming Intel dictated the ATX12V 2.0 spec for their own benefits to begin with.

Now it could work on a single rail PSU but as previously quoted, I wouldn't wanna risk the life of the PSU & possibly hardware connected to it.

Originally posted by: FastEddie
And you make it sound like the dual rail psu is the next best thing to come down the pipe since sliced bread.

If all it took was a quote from THG to make it sound like the next biggest thing, I don't think I'm doing multi-rail PSUs justice in all fairness. I could've went further into the merits of dual/multi-rails if that was my intention.

Originally posted by: FastEddie
My point is that the technology has been here awile, and was designed for a totally different animal than what we have with NF4/Sli.

That's your conclusion, that argument will be in complete reverse once SLI's power needs (assuming it flourishes) exceeds the power output capacity that single rail PSUs can deliver. Meaning I don't think either, single or multi rail, was designed for SLI or vice versa. I surmise it's similar to saying there's the Northwood & Prescott, & an application comes along which happens to favor Northwood at lower CPU frequencies & Prescott at higher CPU frequencies - minus the heat problems. Would you say that application was designed for either of them, no. It's just the circumstance at the time.

Originally posted by: FastEddie
The dual rail tech evolved around the Intel architecture, not AMD.

If dual rails have to start somewhere, why not Intel to start it up? They are afterall the market leader & anyone that wasn't sleeping underneath a rock would see the trend that a lot of things are going dual on the desktop e.g. CPUs, memory, GPUs, hard drives (RAID 0), etc.

Originally posted by: FastEddie
But when incorporated into AMD, it was tweaked for multiprocessor/multi-memory bank K7 architecture---not the current K8, which moved most of the current demand to the 12v rail.

I'm lost here, how was the PSU design "tweaked"? AFAIK some dual rail PSUs are made for the P4/K8 and disregard the K7 platform & then there are dual rail PSUs that have no problems powering the K7 platform with both rails. I'll explain further what I mean, the Antec Neopower has one rail dedicated to the P4 connector alone, now since the K7 platform doesn't receive +12V power via the P4 4-pin connector, that rail is pretty much unused (shame on Antec in this case). On the other hand the Enermax unit is designed to power the P4 connector & main 20/24-pin connector via the same rail, therefore both rails are utilized on a K7 based system.

Note that I don't see it being a big factor since dual rail PSUs for the desktop came out at or a little after the A64 and by that time both companies [Intel & AMD] utilized the +12V P4 connector on their latest platforms. Granted there are cases where someone who needs a new PSU cause their old PSU crapped out on their K7 based system may shop for a dual rail PSU, which is unfortunate if they get a Neopower. Which brings the question, does Antec recommend you not use the Neopower on a K7 based system on their packaging? If not supposedly they think 18A was strong enough for any K7 based system?

Originally posted by: FastEddie
That particular version of the Enermax hasn't changed the internal components or ratings to take K8 into consideration, let alone the lopsided demands of Sli. So to mearly add a couple of pci-e power connectors and claim that it's the holy grail for NF4/Sli is really stretching it's capabilities to fulfill that demand.

It powers K8 & SLI just fine until I see otherwise. Again, got proof the Enermax unit can't? Cause if wanted I can pull evidence that it does indeed work with K8 & SLI.

Originally posted by: FastEddie
The key here is Older ATX (1.0) power supplies..... The statement is true for that qualifier---older. Not all ATX 2.0 psu's have two 12v lines or seperate rails

I suppose none of us here in ATF are guilty of having said ATX 2.0 when we really meant ATX12V 2.0? If you look into the white papers, if memory serves the ATX spec doesn't suggest multi-rails, however ATX12V 2.0 does & the only ATX12V 2.0 PSUs that shouldn't have more than 2+ rails are the ones that don't exceed 18A, as specified in the ATX12V 2.0 specs.

Originally posted by: FastEddie
high output/high amperage single rail ATX 2.0 psu's are designed to function properly using a constant power drain in a range of 60-80% of its peak output. No psu should have to run above 90% of its peak output on a continous basis (as in constant use). That is not an element of their design, nor is it an efficient use of the power resource.

Are you speaking as an electrical engineer? Are there sources that say you can't fully load one of the rails up on a multi-rail PSU without experiencing problems? Perhaps that applies only to single rail PSUs cause when the rail on a single rail PSU is fully utilized, the total output of the PSU is maxed out as well. With the dual rail in question, when you max out just one of it's rails, you don't exactly max out the PSU's entire +12V power output capability.

 

[Algere]

Originally posted by: flexy
I have this same Enermax (the one with 20pin which i modded to 24pin)...i am positive the 24pin version is *identical* to the 20p except that they added the connectors.

I think its kinda emberrassing to read on eg. Antec's website where they try to make people believe that it's only a "half ass" solution because its not REAL ATX2.0 and only an ATX1.3 (one rail) with 24pin.....but to be HONEST...WHO CARES ???

This is an exceptional good PSU which i have running on a heavily overclocked dfi lanparty nf4 board w/ an overclocked, very powerhungry X850XT.

My multimeter shows that eg. the 12V rail NEVER, ever went below 12.1 under load (idle 12.2)...and people can rant hours and hours what a halfa$$ solution it is because "it has no TWO rails and is not real ATX2.0" or Antec can blame their competitors (mainly Enermax) as selling "pseudo ATX2.0" PSUs which (SUPPOSEDLY) are not that good....that's all worthless if i see the EXCELLENT performance of this PSU in real life.

I dont know what else to add,..but i would take this PSU anytime again (but then the one with 24p just to save me the hassle of making a plug myself ) - and it would take a LOT to make me believe that i really need a $250 PC&P or a 600W OCZ or whatever OTHERWISE i would be unable to overclock my memory or CPU or would run into whatever problems.

The ~80 or so i paid a while ago for this PSU are proof that you do NOT need to spend a fortune and still can get high quality...and that you do NOT need ATX2.0 and two rails.

I am running an A64 3500+ w/ 2x 512MB OCZ 3200 EL Plat Rev2 at
9x289 = 2601 (2.5 4 3 7 1T, 1:1) w/ X850XT overclocked - no problems.

Your PSU is a version 1.3 Enermax Noisetaker?

 

[flexy]

its this one
http://www.ocsystem.com/en45peak462f3.html

 

[mi11er]

Originally posted by: flexy
addendum (for clarification):

If your PSU has only 15A on the rail...well...subtract 9.2A and this doesnt leave MUCH for the rest...

It worked fine for me using 350W ATX (20-pin) rated with 12A for +12V rail for powering
P4 XE 3.73GHz and Radeon X800XT PCI-E...
sounds doubtful but I run complete benchmarks on that system!?...

 

[Ike0069]

Simple question here.
If I have a 20 pin PSU, and my PCI-e VC does not have a way to connect power to it directly, how does it get power?

 

[Algere]

Originally posted by: Ike0069
Simple question here.
If I have a 20 pin PSU, and my PCI-e VC does not have a way to connect power to it directly, how does it get power?

It can get power from the motherboard's PCIe slot and from a 6-pin PCIe power plug if available. On some SLI based motherboards if you're missing the 4-pins (PCIe power) of a 24-pin plug AKA 20-pins, the motherboard may come with a 4-pin molex connector instead for which additional power can be tapped.

 

[Ike0069]

Originally posted by: Algere

Originally posted by: Ike0069
Simple question here.
If I have a 20 pin PSU, and my PCI-e VC does not have a way to connect power to it directly, how does it get power?

It can get power from the motherboard's PCIe slot and from a 6-pin PCIe power plug if available. On some SLI based motherboards if you're missing the 4-pins (PCIe power) of a 24-pin plug AKA 20-pins, the motherboard may come with a 4-pin molex connector instead for which additional power can be tapped.

So if this is not an SLI based MB, how does it get power from th MB with only a 20 pin PSU? I thought the extra 4 pins were only for the PCI-e slot. Is there a adapter to take a molex connector to the extra 4 MB slots?

 

[Algere]

Originally posted by: Ike0069

Originally posted by: Algere

Originally posted by: Ike0069
Simple question here.
If I have a 20 pin PSU, and my PCI-e VC does not have a way to connect power to it directly, how does it get power?

It can get power from the motherboard's PCIe slot and from a 6-pin PCIe power plug if available. On some SLI based motherboards if you're missing the 4-pins (PCIe power) of a 24-pin plug AKA 20-pins, the motherboard may come with a 4-pin molex connector instead for which additional power can be tapped.

So if this is not an SLI based MB, how does it get power from th MB with only a 20 pin PSU? I thought the extra 4 pins were only for the PCI-e slot. Is there a adapter to take a molex connector to the extra 4 MB slots?

Some of those 20 pins provide +12V power to the PCIe slots. If a 20-pin PSU can deliver enough +12V through those 20 pins alone, then the additional 4 pins (of a 24-pin power plug) shouldn't matter much for today's 24-pin motherboards. 24-pin motherboards of tomorrow will probably require a 24-pin PSU.

 

[Creston]

I got an Aspire case with a 500W power supply in it, figuring that 500W should be more than plenty to power my new system (and probably way too much..)

However, I've been having some freezing issues with it. For details, you can check out the thread I posted in tech support (http://forums.anandtech.com/messageview...tid=32&threadid=1554561&enterthread=y)

After reading parts of this thread, and several reviews on PSUs, I'm beginning to wonder if my PSU does not have enough Amps on the 12V line to keep up with my apparently pretty power hungry X800XL. (which would seem pretty consistent with the behavior mentioned in the tech support thread, I think?)

However, it's a PSU that came with the system, and I have no details on it. Is there any way of figuring out how much Amps it has, short of getting a multimeter and jabbing it into several areas and hoping it will give me a reading which I still won't know what it means?

Thanks for any help.

Creston