Be Quiet Dark Power Pro 13 - 1300w

[blahoink01]

I know this is old news, and I'll sound a bit uneducated here. I was having hard, lights out type crashes with a Gigabyte RTX 5090 Gaming OC. I searched high and low and went through every system component. I concluded one of the following three were at fault: the card was bad, power supply was faulty, or maybe the electrical circuit was overloaded. I have a Be Quiet Dark Power Pro 13 - 1300w to power the system. It turns out there is an "overclock jumper" with very little documentation. It simply converts the 12V rails to a single rail setup. Apparently, the Dark Power Pros (1300 and 1600) have very sensitive OCP. I've had zero hard shut downs since installing the jumper. I'm not a PSU expert so I'm looking for feedback if this change was correct & safe?

 

[Bill_Bright]

I'm not a PSU expert so I'm looking for feedback if this change was correct & safe?

Since it is working now, then it was correct. And yes, it is safe.

Frankly, I wish the option/feature didn't even exist.

Many MANY years ago, there was a marketing push for "multi-rail" PSUs. The [so-called] theory behind it was to created a sort of "pseudo" dual PSU setup with the idea being, should there be a failure on one rail, it would be isolated to that one rail and thus, insure no damage to the components connected to the other rail. It also "supposedly" would prevent one power hungry device (GPU for example) hogging all the power from another device (like the CPU).

It was based on the real-world practice of using multiple PSUs for mission critical systems. In the event one PSU failed, the redundant supply kept the system running, and ensures every device got the power it needed.

But that redundancy capability is impossible to achieve when the single PSU has just one AC input and a single input transformer and a single set of filter caps for that one transformer. So this marketing "push" turned out to be nothing more than pure marketing "hogwash!" The ONLY way to truly get such protection and redundancy is to use two separate PSUs.

The problem with this feature to split one big rail into multiple rails is exactly what you encountered - the full capacity/capability of the PSU cannot be accessed on any one of the rails because some power is always delegated to each rail - even if nothing is connected to the other rails!

On top of the that, the better PSUs (even back then) are (and were then) pretty smart by design (and, in fact, in most cases, by national and international safety regulations and codes). If they sense a potentially dangerous situation (internally or with a connected device), the entire PSU shuts down output to prevent any collateral damage to the computer components - or prevent catching fire, burning down the house, and ruining the user's day!

Lesson learned is with a properly sized PSU, a single rail system will easily support all the components AND ensure each has the power it needs when it is needed.

Note too, designing and manufacturing a multi-rail PSU cost more. The design is more complex and it requires more parts and thus costs more to build. Then because it has more parts, there are more potential points of failure.

Sadly some companies still market multi-rail PSUs. But make no mistake, it is a marketing "gimmick" designed to earn the company more profit. There is NO technical advantage to using multiple rails in a computer UNLESS the rails are totally isolated by using two PSUs. And even then, the advantage is limited. If a system is that critical, use mirrored computers.

 

[blahoink01]

Since it is working now, then it was correct. And yes, it is safe.

Frankly, I wish the option/feature didn't even exist.

Many MANY years ago, there was a marketing push for "multi-rail" PSUs. The [so-called] theory behind it was to created a sort of "pseudo" dual PSU setup with the idea being, should there be a failure on one rail, it would be isolated to that one rail and thus, insure no damage to the components connected to the other rail. It also "supposedly" would prevent one power hungry device (GPU for example) hogging all the power from another device (like the CPU).

It was based on the real-world practice of using multiple PSUs for mission critical systems. In the event one PSU failed, the redundant supply kept the system running, and ensures every device got the power it needed.

But that redundancy capability is impossible to achieve when the single PSU has just one AC input and a single input transformer and a single set of filter caps for that one transformer. So this marketing "push" turned out to be nothing more than pure marketing "hogwash!" The ONLY way to truly get such protection and redundancy is to use two separate PSUs.

The problem with this feature to split one big rail into multiple rails is exactly what you encountered - the full capacity/capability of the PSU cannot be accessed on any one of the rails because some power is always delegated to each rail - even if nothing is connected to the other rails!

On top of the that, the better PSUs (even back then) are (and were then) pretty smart by design (and, in fact, in most cases, by national and international safety regulations and codes). If they sense a potentially dangerous situation (internally or with a connected device), the entire PSU shuts down output to prevent any collateral damage to the computer components - or prevent catching fire, burning down the house, and ruining the user's day!

Lesson learned is with a properly sized PSU, a single rail system will easily support all the components AND ensure each has the power it needs when it is needed.

Note too, designing and manufacturing a multi-rail PSU cost more. The design is more complex and it requires more parts and thus costs more to build. Then because it has more parts, there are more potential points of failure.

Sadly some companies still market multi-rail PSUs. But make no mistake, it is a marketing "gimmick" designed to earn the company more profit. There is NO technical advantage to using multiple rails in a computer UNLESS the rails are totally isolated by using two PSUs. And even then, the advantage is limited. If a system is that critical, use mirrored computers.

Great reply and thanks for the feedback.

 

[Bill_Bright]

YW.

 

[EarthDog]

Yes is the short answer...

... but it depends on what card you have (???? No system specs listed, nor was it mentioned in the first post), how the PSU splits the rails in the first place and what you're using (6+2 or 12vhpwr/12v2x6). Multi-rail configs are 'dated' to me. With the last few gens of power hungry cards coming out, multi-rail PSUs can trip because there isn't enough power on the 12V rails for the card without tripping OCP. Multi-rail PSUs had their time and place, but for the most part, it isn't now. But, I'd guess you have a high power card and it simply tripped the 12V OCP for that rail.

Another way to do it, if the PSU labels things and you can, is to split use multiple rail inputs on the card (if possible / if you're not using a single 12vhpwr/12v2x6). That said, unless you have a 5090, it shouldn't trip in the first place if you put the GPU on the right rail(s) (unless it's OCP is set lower than the listed specs). You PSU has two 12V rails capable of up to 55A (according to its specs)......some napkin math says that's 660W of power........ so unless you have a 5090 on steroids that PSU shouldn't be tripping assuming your connector(s) are plugged into the right rail(s).......... which, looking at the PSU connections, feels impossible, lol.

 

[dirtyferret]

Yes is the short answer...

... but it depends on what card you have (???? No system specs listed, nor was it mentioned in the first post), how the PSU splits the rails in the first place and what you're using (6+2 or 12vhpwr/12v2x6). Multi-rail configs are 'dated' to me. With the last few gens of power hungry cards coming out, multi-rail PSUs can trip because there isn't enough power on the 12V rails for the card without tripping OCP. Multi-rail PSUs had their time and place, but for the most part, it isn't now. But, I'd guess you have a high power card and it simply tripped the 12V OCP for that rail.

Another way to do it, if the PSU labels things and you can, is to split use multiple rail inputs on the card (if possible / if you're not using a single 12vhpwr/12v2x6). That said, unless you have a 5090, it shouldn't trip in the first place if you put the GPU on the right rail(s) (unless it's OCP is set lower than the listed specs). You PSU has two 12V rails capable of up to 55A (according to its specs)......some napkin math says that's 660W of power........ so unless you have a 5090 on steroids that PSU shouldn't be tripping assuming your connector(s) are plugged into the right rail(s).......... which, looking at the PSU connections, feels impossible, lol.

Look who's alive and out of retirement!

 

[blahoink01]

Yes is the short answer...

... but it depends on what card you have (???? No system specs listed, nor was it mentioned in the first post), how the PSU splits the rails in the first place and what you're using (6+2 or 12vhpwr/12v2x6). Multi-rail configs are 'dated' to me. With the last few gens of power hungry cards coming out, multi-rail PSUs can trip because there isn't enough power on the 12V rails for the card without tripping OCP. Multi-rail PSUs had their time and place, but for the most part, it isn't now. But, I'd guess you have a high power card and it simply tripped the 12V OCP for that rail.

Another way to do it, if the PSU labels things and you can, is to split use multiple rail inputs on the card (if possible / if you're not using a single 12vhpwr/12v2x6). That said, unless you have a 5090, it shouldn't trip in the first place if you put the GPU on the right rail(s) (unless it's OCP is set lower than the listed specs). You PSU has two 12V rails capable of up to 55A (according to its specs)......some napkin math says that's 660W of power........ so unless you have a 5090 on steroids that PSU shouldn't be tripping assuming your connector(s) are plugged into the right rail(s).......... which, looking at the PSU connections, feels impossible, lol.

Thanks EarthDog. I got a little lazy there. I listed the main culprits Gigabyte RTX 5090 Gaming OC & Be Quiet Dark Power Pro 13 - 1300w. I had no issues with a series of other cards and all the same components in the box so I left off the other system specs. I was using the PCIe 5.1 12vhpwr cable from Be Quiet. I also had multiple cables, and they didn't resolve the issue.

I've never paid close attention to multi vs single rail PSUs as I've never had an issue with modern, high-wattage PSUs. I had a wall plug monitor on and used afterburner/riva to check GPU wattage live. I didn't see anything unusual leading up to the hard power shutdowns. I think Be Quiet's naming of the single rail function as "overclocking" didn't make it any easier to troubleshoot.

To your point, I thought about just using the 12vhpwr splitter to traditional PCIe plugs to divide the power up among the rails. Maybe the rails have very sensitive OCP. In TPU's testing back in February the card hit 646w when measuring 20ms spikes. I'm going to assume it isn't a stretch some protections were being bumped. Again, I haven't exactly made a deep study of PSU electrical systems so I've appreciated the responses.

 

[EarthDog]

Yeah, in theory, it should allow up to 660W.... in theory. Looks like it isn't living up to it's billing or something. But the easiest way is what you did. Enjoy that rig.