PSU Wattage and SATA Connection

[Fastline]

Hello,

So, i'm having the following hardware:

Supermicro X11SPH-nCTPF
Intel Xeon Gold 6142R
8x128GB ECC DDR4 2933MHz
16xSeagate EXOS X18 16TB
1xLSI 9400-16i
25GbE Intel XV710 NIC
9x140mm FANs
4x40mm FANs
Antec Signature 1300W

And I have a couple of questions

1. Will be the PSU wattage sufficient during peak loads?

2. Regarding the output, here's the PSU breakdown from the official site:

As per the X18 datasheet for 16TB, the drive takes roughly like 1.00A and consumes like 5.3W for a single drive. So, does that mean i can connect up to roughly 20 drives which will be consuming 106W in total and 20A. The rest is reserved for peak loads. Is my calculation right here or am i missing something?

 

[joeschmuck]

Have you read the resource Hardware Guide? This should provide you the answer you are looking for.

Hardware Recommendations Guide - History

www.truenas.com

 

[Fastline]

Have you read the resource Hardware Guide? This should provide you the answer you are looking for.

Hardware Recommendations Guide - History

www.truenas.com

Well, i read that already and 1300W seems fine to me. But i wanted some opinions as if it is not adequate, i can buy a different PSU.

 

[Davvo]

Also the following.

Proper Power Supply Sizing Guidance

I've seen about 1,000 threads like this one where people decide that they can power a dozen hard drives off a 360 watt supply. DO NOT DO THIS. I've seen another 1,000 threads where people decide to buy the cheapest power supply that they can...

www.truenas.com

 

[joeschmuck]

Also the following.

Proper Power Supply Sizing Guidance

I've seen about 1,000 threads like this one where people decide that they can power a dozen hard drives off a 360 watt supply. DO NOT DO THIS. I've seen another 1,000 threads where people decide to buy the cheapest power supply that they can...

www.truenas.com

That link is in your resource already under the power supply section, which is why I recommended it. Geez, I'm trying to get someone to read all the hard work you do and this is the thanks I get.

Well, i read that already and 1300W seems fine to me. But i wanted some opinions as if it is not adequate, i can buy a different PSU.

So, does that mean i can connect up to roughly 20 drives which will be consuming 106W in total and 20A.

Nope. Do not forget that the motherboard and CPU consume a lot of power. My new motherboard has the ATX power connector and two additional 8 pin 12VDC plugs for the CPU, that is a lot of wire to power the system. Your math is not quite correct. You just don't know how to calculate voltage (V), current (I), and power (W).

If a drive consumes 5.2 watts at 12VDC then that equals ~0.41 amps. This means that IF you used this power supply ONLY to power hard drives, you could power 108A / 0.41 = 263 drives. Or you could say 1296 Watts / 5.3 Watts = 244 drives. There is a little bit of a discrepancy due to not using precise values but you get the point. NOT that anyone would recommend trying to use a power supply at it's full capacity 100% of the time.

20 drives at 5.4 watts is 108 Watts, which is 9 Amps. Volts x Amps (I) = Watts.

Will your power supply work? yes, I'm sure it will.

But drive power consumption is not all of it as I mentioned before. And I hope I didn't confuse you, that was not my intention. I have personally never run 20 hard drives, I don't think I ever want to. The wife would hang me if I did.

 

[Fastline]

Also the following.

Proper Power Supply Sizing Guidance

I've seen about 1,000 threads like this one where people decide that they can power a dozen hard drives off a 360 watt supply. DO NOT DO THIS. I've seen another 1,000 threads where people decide to buy the cheapest power supply that they can...

www.truenas.com

Thank you for this guide. I had a full reading right now.

It was my bad that i misread the datasheet. The idle watt was 5. So, now it might be taking up to 25-30W during load. Also, i was confused that it will be on a 5V rail. xD

All good now :)

 

[Davvo]

Make sure to account for peak loads.

 

[Fastline]

That link is in your resource already under the power supply section, which is why I recommended it. Geez, I'm trying to get someone to read all the hard work you do and this is the thanks I get.

Aye aye, i replied late as i was reading Davvo's linked guide. Tell me where to send the gifts ;)

Nope. Do not forget that the motherboard and CPU consume a lot of power. My new motherboard has the ATX power connector and two additional 8 pin 12VDC plugs for the CPU, that is a lot of wire to power the system. Your math is not quite correct. You just don't know how to calculate voltage (V), current (I), and power (W).

You're right here. I was so confused. The guide which Davvo linked, cleared up all my confusion now :)

If a drive consumes 5.2 watts at 12VDC then that equals ~0.41 amps. This means that IF you used this power supply ONLY to power hard drives, you could power 108A / 0.41 = 263 drives. Or you could say 1296 Watts / 5.3 Watts = 244 drives. There is a little bit of a discrepancy due to not using precise values but you get the point. NOT that anyone would recommend trying to use a power supply at it's full capacity 100% of the time.

Of course, of course, i get the math now :)

20 drives at 5.4 watts is 108 Watts, which is 9 Amps. Volts x Amps (I) = Watts.

But ain't that idle power consumption? The drive would take roughly 30W as per the guide. So that means 20x30W=600W. OMG. 600W just for the drives. Is that real?

However, when i check the datasheet from Seagate, it tends to appear roughly at 10W. Am i still missing something here?

Will your power supply work? yes, I'm sure it will.

I hope so. I'm having an eye at Seasonic 1600W Titanium

But drive power consumption is not all of it as I mentioned before. And I hope I didn't confuse you, that was not my intention.

Of course not dear friend :) In fact, you helped me a lot to understand the basics. Kudos!

I have personally never run 20 hard drives, I don't think I ever want to. The wife would hang me if I did.

 

[Davvo]

But ain't that idle power consumption? The drive would take roughly 30W as per the guide. So that means 20x30W=600W. OMG. 600W just for the drives. Is that real?

At startup, yes. If I am reading that table correctly (using the lower DC values... because the PSU supplies DC Power, not AC):
0.96A * 5V = 4.8W on the 5V rail per each drive
1.66A * 12V = 19.9W on the 12V rail per each drive
That brings you a total of 96W (5V) and 398W (12V) just for spinning the plates up. Take a second look at the 5V + 3.3V rail of your PSU... with just the drives you are reeeeally close to the 20% margin you generally want to have: that's why the 5V rail is so critical.

Most drives take up to about 2.1 amps of additional current on the 12 volt rail to start the platters spinning - that's 25 watts per drive. This is in addition to the eight watts that the drive electronics may be consuming

 

[Constantin]

The initial surge is the reason that most arrays stagger-start their drives. It costs virtually nothing and saves a lot on the PSU costs by limiting peak power needs.

But as @jgreco has pointed out, arrays don’t always behave as expected and a simultaneous boot for whatever erroneous reason can put a serious strain on PSUs. I’d also wager that the PSUs made for SM 847 and like chassis are optimized for hordes of drives, perhaps more so than the ATX PSUs SOHO folks use. Plus, they’re available redundant, etc.

Knowing exactly what each drive pulls and when is something I’d love to investigate sometime. We have the right tools at work but I don’t have the time ATM. Results would be n=1 etc. But in the old days they had to pour a pad and put in a new transformer to boot the HDD in the Vax 750 / PDP 11 at school. That thing was a beast, the size of a small fridge, and allegedly drew 50A @ 460V for a short time at boot. Seems excessive…

 

[joeschmuck]

But ain't that idle power consumption?

Yes it is. I took the value you specified in an earlier posting so it looks like you posted that value. But then you did post the spec sheet data, lots of good information however based on those specs I would use the highest 5VDC amps and the highest 12VDC amps, even though they are not for the same operation, then calculate out the maximum amps for each voltage. This gives us 2.37 Amps for the 12 volt section or 28.44 Watts, and 1.27 Amps for the 5VDC section or 6.35 Watts. For 20 drives that would be 127 watts (25.4 Amps) for 5VDC and 569 Watts for 12VDC (47.4 Amps).

And that is just for the 20 drives. So the 1300 Watt power supply would not be suitable as you would be slightly over the 5VDC maximum current. But the 12VDC is perfectly fine. And of course this does not take into account other power you need to supply.

Oh yes, and the rating you see on the products are what the manufacturer is saying, and how long can that be sustained, how much THD is introduced when you are near the maximum capacity, I'm thinking too much for me because the power supply is going to be struggling. I like the Power Supply Sizing Guide, but I calculate all that out myself, always have. Then I make the best educated choice.

I know you have all the data to make a good decision. The 1600 watt may be a better choice. And I would not get hung up on Titanium vs Platinum vs Gold. Look up what these ratings actually mean and if the added cost justifies the higher level. In my book if it's an 80 Plus rated power supply from a reputable company, it is good enough. I personally like Gold but I do compare prices. Sometimes the next level up is $5.00 USD more. Of course, in your specific situation a few percent of efficiency may pay off as you are going to be feeding that beast some electricity.

Best of luck to you and if/when you build this, you should take some readings with a Amp/Watt meter if you have one. They are not expensive.

 

[Fastline]

At startup, yes. If I am reading that table correctly (using the lower DC values... because the PSU supplies DC Power, not AC):
0.96A * 5V = 4.8W on the 5V rail per each drive
1.66A * 12V = 19.9W on the 12V rail per each drive
That brings you a total of 96W (5V) and 398W (12V) just for spinning the plates up. Take a second look at the 5V + 3.3V rail of your PSU... with just the drives you are reeeeally close to the 20% margin you generally want to have: that's why the 5V rail is so critical.

yeap

 

[Fastline]

Yes it is. I took the value you specified in an earlier posting so it looks like you posted that value. But then you did post the spec sheet data, lots of good information however based on those specs I would use the highest 5VDC amps and the highest 12VDC amps, even though they are not for the same operation, then calculate out the maximum amps for each voltage. This gives us 2.37 Amps for the 12 volt section or 28.44 Watts, and 1.27 Amps for the 5VDC section or 6.35 Watts. For 20 drives that would be 127 watts (25.4 Amps) for 5VDC and 569 Watts for 12VDC (47.4 Amps).

Yes, yes. Right right. I was confused and did not pay attention. When i read the post carefully, i checked the datasheet again and found that it was idle power. xD

So, for the 1300W, it is rated 106A, 1296W for 12VDC and i guess for the initial spin up, that is under the limit and for the 5VDC, it is rated as 25A, 125W which is little way up for the 20 Drives so kinda overloading the PSU. However, that is for 20 drives, which was a rough numbers. I guess i would max it out by 18 Drives so the math would be the following:

18x5VDC = 114.3 (22.86A) (25A, 125W limit)
18x12VDC = 511.92 (42.66A) (106A, 1296W limit)

That seems to be under the limit or am i still at risk? The thing is, i have this Antec 1300W from my another machine which doesn't have that much requirements and i can simply swap out instead of buying a new one.

Also, during normal operation, each drive would take like 10W in total, yeah?

And that is just for the 20 drives. So the 1300 Watt power supply would not be suitable as you would be slightly over the 5VDC maximum current. But the 12VDC is perfectly fine. And of course this does not take into account other power you need to supply.

Yes, i get it totally and you're absolutely right. I'm not sure what other components would need a 5VDC supply other than the HDD/SSD. As far as I'm aware, none of my peripherals will use 5VDC. It will just be the drives only. Oh, damn, i just checked and it seems like the ATX 24 PIN also uses some 5VDC.

However, no matter even if i go for this Seasonic Prime PX 1600W, it has same output for the 5VDC as the Antec:

So, here also the 5VDC is capped at 25A and 125W. As my 12VDC loads are already sufficient, how do i find a right PSU which has more than 25A, 125W for the 5VDC? Cause even if i buy 1600W, i would be slightly over the 5VDC maximum rated output.

Even in worse case if i somehow just get another PSU just for the drives, I'm exceeding the 5VDC rated output.

I'm lost now ;(

Oh yes, and the rating you see on the products are what the manufacturer is saying, and how long can that be sustained, how much THD is introduced when you are near the maximum capacity, I'm thinking too much for me because the power supply is going to be struggling. I like the Power Supply Sizing Guide, but I calculate all that out myself, always have. Then I make the best educated choice.

Yeah, yeah. You're a PRO. I've just started the journey ;)

I know you have all the data to make a good decision. The 1600 watt may be a better choice.

I think that too.

And I would not get hung up on Titanium vs Platinum vs Gold. Look up what these ratings actually mean and if the added cost justifies the higher level. In my book if it's an 80 Plus rated power supply from a reputable company, it is good enough. I personally like Gold but I do compare prices. Sometimes the next level up is $5.00 USD more. Of course, in your specific situation a few percent of efficiency may pay off as you are going to be feeding that beast some electricity.

Hehehe. Yes, yes, i get your point totally.

Best of luck to you and if/when you build this, you should take some readings with a Amp/Watt meter if you have one. They are not expensive.

Thanks man. Of course, I'm going to do that for sure! Will tag you when it is done :)

 

[Davvo]

Look into staggered spinup or the CORSAIR AX1600i. Do however note that the proper way of conveniently powering such an array is beyond my knowledge... you need the opinion of someone with hands-on experience.

 

[joeschmuck]

The thing is, i have this Antec 1300W from my another machine which doesn't have that much requirements and i can simply swap out instead of buying a new one.

So use it. We are using maximum power numbers and I doubt you will hit that ceiling, but you never know.

If you do not own a device similar to the "Kill a Watt" or similar, you should invest in one. I use mine when I build a system or if I need to figure out if my refrigerator is in trouble. Most people will just use it to see what a system uses for power. These do not cost much. If you have one then you can place your computer on it and take measurements. Start with no hard drives, just the motherboard. If you like, put in a MemTest86 bootable flash drive, monitor the WATTS being used. Also the Power Factor (pf) might be good to write down. This is an efficiency rating. While the MemTest86 is running, you have one baseline. Now use a bootable CPU stress test, write down the values again. These are a great place to start and say that this is the maximum power your motherboard will pull. In reality you likely will never get there more than a fraction of a second at a time, but reality will tell you it runs more at Idle that anything else, unless you plan to run some VMs.

So you have values for just the motherboard now. Time to add in a hard drive, one is a good start. Boot the system back up using the same Memtest86 boot drive (because you already know what the motherboard values are). Note all the power readings when you power on the system, it will happen fast so you may need to power off and power on a few times to get the data. And subtract out the motherboard values. Now you know what a single drive uses for power.

BUT WAIT, there is more. Install a total of 6 drives, take all the readings again, this time after you subtract out the motherboard, you would divide by 6. Your values of a single drive compared to one of six drives might be different. Of course make sure you are not getting close to the power supply maximum power rating.

Keep adding drives in some sort of arrangement that makes sense to you. When you finally get to 18 drives, figure out if you have exceeded the power or not. If your power supply has a fan that speeds up due to temperature, you do not want it running at high speed all the time.

If at anytime during this process you get close to the maximum power of the power supply, STOP. There is no need to damage a power supply.

This kind of analysis can help you out and you can then make that educated decision.

I hope that all makes sense. I can tell you that some people would not do this kind of testing, they either do not trust themselves or the hardware and if they screw it up, it can be costly, so they just drop a chunk of money on a large power supply. They can do that and I would never give them crap for doing that. If you are careful with what you are doing, you can do it safely. But if you get to 15 drives and you forget to subtract the full power load of the motherboard while running the CPU stress test, you are setting yourself up for failure. You must have attention to detail. A good spreadsheet to track all your data is very handy.

I too do not know how to stagger the drives from spinning up.

Let us know the path you chose.

-Joe

 

[Fastline]

Look into staggered spinup or the CORSAIR AX1600i. Do however note that the proper way of conveniently powering such an array is beyond my knowledge... you need the opinion of someone with hands-on experience.

Not heard about it before. I hate CORSAIR PSUs and never going to buy one with the bad experiences i had with their PSUs over the years ;(

 

[Fastline]

So use it. We are using maximum power numbers and I doubt you will hit that ceiling, but you never know.

If you do not own a device similar to the "Kill a Watt" or similar, you should invest in one. I use mine when I build a system or if I need to figure out if my refrigerator is in trouble. Most people will just use it to see what a system uses for power. These do not cost much. If you have one then you can place your computer on it and take measurements. Start with no hard drives, just the motherboard. If you like, put in a MemTest86 bootable flash drive, monitor the WATTS being used. Also the Power Factor (pf) might be good to write down. This is an efficiency rating. While the MemTest86 is running, you have one baseline. Now use a bootable CPU stress test, write down the values again. These are a great place to start and say that this is the maximum power your motherboard will pull. In reality you likely will never get there more than a fraction of a second at a time, but reality will tell you it runs more at Idle that anything else, unless you plan to run some VMs.

So you have values for just the motherboard now. Time to add in a hard drive, one if a good start. Boot the system back up using the same Memtest86 boot drive (because you already know that the motherboard values are). Note all the power readings when you power on the system. it will happen fast so you may need to power off and power on a few times to get the data. And subtract out the motherboard values. Now you know what a single drive uses for power.

BUT WAIT, there is more. Install a total of 6 drives, take all the readings again, this time after you subtract out the motherboard, you would divide by 6. Your values of a single drive compared to one of six drives might be different. Of course make sure you are not getting close to the power supply maximum power rating.

Keep adding drives is some sort of arrangement that makes sense to you. When you finally get to 18 drives, figure out if you have exceeded the power or not. If your power supply has a fan that speeds up due to temperature, you do not want it running at high speed all the time.

If at anytime during this process you get close to the maximum power of the power supply, STOP. There is no need to damage a power supply.

This kind of analysis can help you out and you can them make that educated decision.

I hope that all makes sense. I can tell you that some people would not do this kind of testing, they either do not trust themselves or the hardware and if they screw it up, it can be costly, so they just drop a chunk of money on a large power supply. They can do that and I would never give them crap for doing that. If you are careful with what you are doing, you can do it safely. But if you get to 15 drives and you forget to subtract the full power load of the motherboard while running the CPU stress test, you are setting yourself up for failure. You must have attention to detail. A good spreadsheet to track all your data is very handy.

I too do not know how to stagger the drives from spinning up.

Let us know the path you chose.

-Joe

I THINK THIS WILL BE THE COOL THING TO DO. I CANNOT SAY MUCH THIS TIME, BUT JUST A BIG BIG THANK YOU FOR SHOWING ME THE DIRECTION!

I'll update this thread when the components are ready and i have time to test. But I'll do that for sure. Thank you once again mate!

 

[joeschmuck]

I THINK THIS WILL BE THE COOL THING TO DO. I CANNOT SAY MUCH THIS TIME, BUT JUST A BIG BIG THANK YOU FOR SHOWING ME THE DIRECTION!

I'll update this thread when the components are ready and i have time to test. But I'll do that for sure. Thank you once again mate!

I create "off the wall" ideas to get from point A to point B. I don't think you will see that process elsewhere in the forum, but I actually like it. It can really help a person understand where all the electricity is going.

I hate CORSAIR PSUs

I have two right now, one has been working for probably a decade, maybe longer the other I just purchased in November (RM750e) and the reviews were good. It is now in my new TrueNAS computer. Reviews were favorable and so far so good. BUT, I completely understand. All it takes is one bad experience or sometimes multiple experiences. When the wife and I go out to dinner and if it is not good food, we wait at least 6 months before trying it again, the cook might be gone by then. If it sucks again, we wait at least a year. If it sucks again, we never go back. Three strikes. I give electronics two strikes and then unless something changes with the company, I stay away.

Cheers,
-Joe

 

[Fastline]

I create "off the wall" ideas to get from point A to point B. I don't think you will see that process elsewhere in the forum, but I actually like it. It can really help a person understand where all the electricity is going.

Barely on a forum ;)

I have two right now, one has been working for probably a decade, maybe longer the other I just purchased in November (RM750e) and the reviews were good. It is now in my new TrueNAS computer. Reviews were favorable and so far so good. BUT, I completely understand. All it takes is one bad experience or sometimes multiple experiences.

Well, recently, back in 2023 summers i got the same model and Thank God i tested it with the PSU tester i had and boom, the tester was blown right away. Before this, i had some 450W non-modular ones and they worked fine. Over the years, my friend uses Corsair PSUs and he had to do RMA frequently. When he received his last one, i asked him to switch to Antec and since then he had no problems so far.

When the wife and I go out to dinner and if it is not good food, we wait at least 6 months before trying it again, the cook might be gone by then. If it sucks again, we wait at least a year. If it sucks again, we never go back. Three strikes. I give electronics two strikes and then unless something changes with the company, I stay away.

Actually, that's a nice idea to work on the things. Love it!

Cheers!

 

[Fastline]

@joeschmuck

BTW, little bit off topic here. But had a few quick questions.

Is SLOG needed even when you have Flash Storage data vdevs?
Is special vdev (metadata) needed even when you have Flash Storage data vdevs?
Is PLP needed even when you have Flash Storage data vdevs? As far as I'm aware, its for metadata drive, SLOG/L2ARC.