I'm trying to debug some issues with my latest rig (info at bottom) and I started to research the PSU. I searched the ABIT forums and found a post on PSU where someone recommended (for stability) a single rail high amp (35 min) PSU. I did some searching at NewEgg and then looked at my Seasonic and realized it's dual rail. I bought it a few years back after reading some reviews here and never really thought about it until now.
With my specs below should I be looking for a single rail psu? Does it translate to better stability over dual (or more) rails?
Vista 64
Antec P182
ABIT IP35 PRO LGA 775 Intel P35 ATX
EVGA 512 GeForce 8800 GT
Intel Core 2 Duo E8400 Wolfdale 3.0 LGA 775 65W Dual-Core
Corsair XMS2 4GB(2x2GB) 240 Pin DDR2 SDRAM DDR800 (PC2 6400)
Seasonic S12-500 ATX12V 500W PSU
2 Seagate 250gb hard drives (no raid)
1 DVD drive
SB X Fi Platinum
Single vs dual rail PSU
Moderators: NeilBlanchard, Ralf Hutter, sthayashi, Lawrence Lee, Devonavar
Well the whole push back in the day for dual-rails on PSUs was because Intel's ATX12 spec stipulates that no one rail can have more than 240VA (W) running through it (for safety purposes). This means that on the 12V rail, you can't have any line providing more than 20A. The problem with this setup was that with computers nowadays eating up so much of the 12V rail, some power supplies were getting overloaded. The logical way around this was to add a second 12V rail (hence the dual-rails) so that you could have more 12V power without losing the ATX12 certification.
The problem with this system is that if the dual rail is truly implemented, then some cables are one one rail and some on the other, and it's hard to tell the difference. This could mean that it's possible for you to accidentally power all your equiptment with one of the rails while keeping the other rail completely unused. You'd be back to square one.
So a good single-rail power supply will be more convenient since you don't have to worry about accidentally putting all the load on one rail and none on the other. I myself have the Seasonic S12-500 and it's been running strong for a couple years now with some pretty powerful systems, and I've never had a problem with it. At the end of the day, if it were me I'd let brand (and vis a vis, quality) take precidence over single- or dual-rail, and then worry about the rails only as an afterthought.
Long answer short: if you have a good-quality power supply, it shouldn't matter if it's single- or dual-railed. Single railed is harder to mess up, but I've never messed up with a dual-rail power supply so I don't think it's that important.
PS- here's my current system, with no stability problems:
Core 2 Duo E4400 @ 3GHz, 1.45v
ASUS P5K-VM
4x1GB Corsair XMS2 memory @ 800MHz, 5-5-5-15
XFX GeForce 8800GTS 512MB (G92) O/C 740/1850/1125DDR(2250)
Auzentech X-Plosion Sound Card
Seagate Barracuda 7200.10 320GB
NEC Floppy Drive
Lite-On DVD burner
Fans, etc.
Powered by Seasonic S12-500, no problems
...
I also powered a heavily overclocked Prescott system back in the day with the same power supply and had no stability problems. If it was stable with that, I'm sure it's stable with Core 2 systems.
The problem with this system is that if the dual rail is truly implemented, then some cables are one one rail and some on the other, and it's hard to tell the difference. This could mean that it's possible for you to accidentally power all your equiptment with one of the rails while keeping the other rail completely unused. You'd be back to square one.
So a good single-rail power supply will be more convenient since you don't have to worry about accidentally putting all the load on one rail and none on the other. I myself have the Seasonic S12-500 and it's been running strong for a couple years now with some pretty powerful systems, and I've never had a problem with it. At the end of the day, if it were me I'd let brand (and vis a vis, quality) take precidence over single- or dual-rail, and then worry about the rails only as an afterthought.
Long answer short: if you have a good-quality power supply, it shouldn't matter if it's single- or dual-railed. Single railed is harder to mess up, but I've never messed up with a dual-rail power supply so I don't think it's that important.
PS- here's my current system, with no stability problems:
Core 2 Duo E4400 @ 3GHz, 1.45v
ASUS P5K-VM
4x1GB Corsair XMS2 memory @ 800MHz, 5-5-5-15
XFX GeForce 8800GTS 512MB (G92) O/C 740/1850/1125DDR(2250)
Auzentech X-Plosion Sound Card
Seagate Barracuda 7200.10 320GB
NEC Floppy Drive
Lite-On DVD burner
Fans, etc.
Powered by Seasonic S12-500, no problems
...
I also powered a heavily overclocked Prescott system back in the day with the same power supply and had no stability problems. If it was stable with that, I'm sure it's stable with Core 2 systems.
Well I can go look at my rig and see if maybe I am using one rail.
Well, wait a sec, to be honest I'm not sure I know what to look for or what to do about it. I think I have a 6 pin and a 4 pin ATX connector (or maybe it's 8 and 6). I think the 6 pin is on the mb and the 4 pin is on the video card but that can't be right because then a single rail system would not have another connector for a video card. 4 pin molex connectors can't be the rail. I can probably figure this out when I have it in front of me.
Assuming I figure out which connectors are my dual rails, what are they supposed to be split between?
Well, wait a sec, to be honest I'm not sure I know what to look for or what to do about it. I think I have a 6 pin and a 4 pin ATX connector (or maybe it's 8 and 6). I think the 6 pin is on the mb and the 4 pin is on the video card but that can't be right because then a single rail system would not have another connector for a video card. 4 pin molex connectors can't be the rail. I can probably figure this out when I have it in front of me.
Assuming I figure out which connectors are my dual rails, what are they supposed to be split between?
I just can't picture what the physical plug looks like for the rails right now so it's hard for me to guess what is plugged where until I get home. But it's going to be the first thing I check.
I am randomly getting the infamous nvlddmkm nvidia display driver error. I have times when everything goes great then times when it won't go away. I have tested my memory and done a cpu burn test so I think they're safe. Next up is the video card and psu.
I am randomly getting the infamous nvlddmkm nvidia display driver error. I have times when everything goes great then times when it won't go away. I have tested my memory and done a cpu burn test so I think they're safe. Next up is the video card and psu.
Actually maybe the PSU is an issue. I found this for the EVGA 8800GT
Requirements
Minimum of a 400 Watt power supply. (Minimum recommended power supply with +12 Volt current rating of 22 Amp Amps.) Minimum 450 Watt for SLI mode system. (Minimum recommended power supply with +12 Volt current rating of 24 Amp Amps.) An available 6 pin PCI-E power connector (hard drive power dongle to PCI-E 6 pin adapter included with card)
And for my Seasonic the ratings are:
+3.3V@24A,+5V@24A,+12V1@17A,+12V2@17A,
[email protected], [email protected]
So I could be trying to trying to run something that wants 22amp but is only getting up to 17A.
Requirements
Minimum of a 400 Watt power supply. (Minimum recommended power supply with +12 Volt current rating of 22 Amp Amps.) Minimum 450 Watt for SLI mode system. (Minimum recommended power supply with +12 Volt current rating of 24 Amp Amps.) An available 6 pin PCI-E power connector (hard drive power dongle to PCI-E 6 pin adapter included with card)
And for my Seasonic the ratings are:
+3.3V@24A,+5V@24A,+12V1@17A,+12V2@17A,
[email protected], [email protected]
So I could be trying to trying to run something that wants 22amp but is only getting up to 17A.
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MikeC
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The Seasonic really has only one 12V line, so put aside your concerns about which wires relate to which line. My question would be, to troubleshoot this, have you tried another PSU? If the system is stable with another PSU, then you could conclude your old Seasonic has not aged well... or that there's some aspect of the new setup it just doesn't like.
Not that I want to argue with MikeC but doesn't this link http://www.newegg.com/product/product.a ... 6817151024 indicate it has 2 lines? Specifically the part in the output that lists +12V1 and +12V2.
+3.3V@30A, +5V@30A, +12V1@17A, +12V2@16A, [email protected], +5VSB@2A
I haven't used another PSU because I don't have one available. I do have a new 500+ Corsair but it's in the girlfriend's rig and she can't handle the downtime right now, plus it's also a multi-rail psu which would bring back the same question. The other aspect is that I can never force the problem as it seems to come and go, but all that means is I'd have to test for a few days.
+3.3V@30A, +5V@30A, +12V1@17A, +12V2@16A, [email protected], +5VSB@2A
I haven't used another PSU because I don't have one available. I do have a new 500+ Corsair but it's in the girlfriend's rig and she can't handle the downtime right now, plus it's also a multi-rail psu which would bring back the same question. The other aspect is that I can never force the problem as it seems to come and go, but all that means is I'd have to test for a few days.
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MikeC
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Seasonic makes NO multiple 12V line PSUs.
This holds true for PSUs made by Seasonic for other brands, including Corsair, afaik.
Well, let me revise that comment: None of their PSUs have more than one 12V transformer. They may have limiters on specific sets of wires; however, we've never triggered the limiters that are supposed to be there. Like for example, on your S12-500, the current limiter should kick in at 17A and 16A respectively, but this never happened on the test bench, we could easily exceed 20A on either of those lines and the PSU would keep chugging along.
For the record, we've hardly ever triggered the current limiters on ANY power supply, period.
This holds true for PSUs made by Seasonic for other brands, including Corsair, afaik.
Well, let me revise that comment: None of their PSUs have more than one 12V transformer. They may have limiters on specific sets of wires; however, we've never triggered the limiters that are supposed to be there. Like for example, on your S12-500, the current limiter should kick in at 17A and 16A respectively, but this never happened on the test bench, we could easily exceed 20A on either of those lines and the PSU would keep chugging along.
For the record, we've hardly ever triggered the current limiters on ANY power supply, period.
Interesting. I apologize if this is old ground you've covered in a review but to tell the truth most of the details in some of the PSU reviews go over my head. But today I'm learning and it's sinking in for some reason.
Any idea why Corsair is marketing the 520/620 HX has having multiple rails? Or rather why NewEgg would list them as having multiple rails? It would seem to be more than misleading to list it that way if it's really just one 12V transformer. Or if they can do it that way with limiters but the limiters aren't functioning it would also seem like a misleading marketing statement. I've re-read up on the history of the multiple rail / safety issue and it sounds like they're trying to conform to that to get the certification but bypassing the safety aspect to avoid technical problems.
Any idea why Corsair is marketing the 520/620 HX has having multiple rails? Or rather why NewEgg would list them as having multiple rails? It would seem to be more than misleading to list it that way if it's really just one 12V transformer. Or if they can do it that way with limiters but the limiters aren't functioning it would also seem like a misleading marketing statement. I've re-read up on the history of the multiple rail / safety issue and it sounds like they're trying to conform to that to get the certification but bypassing the safety aspect to avoid technical problems.
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MikeC
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Yup, you're right, it's all quite confusing. It took a long time for me to sort through all the BS. There are various places on the site where I've address this issue.
What it comes down to is that there is a safety standard that Intel didn't want to 1) be responsible for ignoring, or 2) encourage other companies to ignore, so they put in this 240VA max per wire recommendation. The only line that could reach that high was the 12V line -- 20A x 12V = 240VA.
PSU makers installed limiters to keep the total current in any 12V wire below 240VA.
Marketing boys walked in and said AHA! Now we can call these multiple, independent 12V lines.
Then the real confusion began.
One immediate issue was due to expanding AUX12V and PCIe 12V power demands. Which wires are tied to which 12V lines? (Your question in the thread originally) The simple fix was for PSU makers to keep just one current limiter -- for the total 12V output -- and claim X number of "lines", because now they were all claiming multiple 12V lines, and no one wanted to admit otherwise.
Anyway, I don't think any of this is your problem. It's simpler than that.... sort of. Either you have a glitch in a RAM stick, on your motherboard, or your PSU is getting worn out (mostly capacitors do wear).
What it comes down to is that there is a safety standard that Intel didn't want to 1) be responsible for ignoring, or 2) encourage other companies to ignore, so they put in this 240VA max per wire recommendation. The only line that could reach that high was the 12V line -- 20A x 12V = 240VA.
PSU makers installed limiters to keep the total current in any 12V wire below 240VA.
Marketing boys walked in and said AHA! Now we can call these multiple, independent 12V lines.
Then the real confusion began. One immediate issue was due to expanding AUX12V and PCIe 12V power demands. Which wires are tied to which 12V lines? (Your question in the thread originally) The simple fix was for PSU makers to keep just one current limiter -- for the total 12V output -- and claim X number of "lines", because now they were all claiming multiple 12V lines, and no one wanted to admit otherwise.
Anyway, I don't think any of this is your problem. It's simpler than that.... sort of. Either you have a glitch in a RAM stick, on your motherboard, or your PSU is getting worn out (mostly capacitors do wear).
Well the RAM tested fine with memtest 2.0 after running all night. I also ran cpu burn for over an hour to make sure the cpu wasn't overheating (the e8400 and the IP35 Pro won't communicate temps with latest bios). AFAIK that leaves (for hardware) the video card and psu. The card is new so it's possibly a problem.
I tore open the case it amazingly found the small book for the psu to see what was what. Here's the connections:
20+4 to mb (of course)
6 pin to 8800gt
8 pin to mb (manual said to use it if you have it)
4 pin to nothing
4 pin molex to mb (near video card)
I did have to stretch the 8 pin to make it connect so it's possible I screwed it up. I thought it odd the manual says the 8 pin is for dual cpu but it is dating a way back.
I do have a cheap psu tester kind of like this one http://www.compusa.com/applications/Sea ... CatId=1107 but not sure if it's accurate enough to diagnose a tricky problem like this that appears to come and go.
I tore open the case it amazingly found the small book for the psu to see what was what. Here's the connections:
20+4 to mb (of course)
6 pin to 8800gt
8 pin to mb (manual said to use it if you have it)
4 pin to nothing
4 pin molex to mb (near video card)
I did have to stretch the 8 pin to make it connect so it's possible I screwed it up. I thought it odd the manual says the 8 pin is for dual cpu but it is dating a way back.
I do have a cheap psu tester kind of like this one http://www.compusa.com/applications/Sea ... CatId=1107 but not sure if it's accurate enough to diagnose a tricky problem like this that appears to come and go.
Here's something odd and new.
When the display driver fails it usually crashes the game with a Microsoft Visual C++ Runtime Library Error. I assumed this was just because the game could no longer communicate to the video driver. The root cause was always in my mind the display driver quitting.
I just kicked off the cascades dx10 demo and I got a Microsoft Visual C++ Runtime Library error from winfah.exe. I wasn't running the graphical part of Folding@Home so why would it have an issue? Plus, Cascades was still going with no issue.
Not sure what this means, if anything.
When the display driver fails it usually crashes the game with a Microsoft Visual C++ Runtime Library Error. I assumed this was just because the game could no longer communicate to the video driver. The root cause was always in my mind the display driver quitting.
I just kicked off the cascades dx10 demo and I got a Microsoft Visual C++ Runtime Library error from winfah.exe. I wasn't running the graphical part of Folding@Home so why would it have an issue? Plus, Cascades was still going with no issue.
Not sure what this means, if anything.