Powering 15 Drives from 1 PSU

[Crusher21]

Below is my current build, already assembled. I currently have 8 drives installed, 14TB each. I plan to add 3 more next week. In the future (when HDD prices drop or there is another sale), I'll
Currently, all 8 drives are connected to the 8 onboard SATA ports on the motherboard. I have purchased an LSI SAS9340-8i to handle the rest of my drives as they come (hopefully it will have the bandwidth).
The problem is...when my LSI HBA comes in the mail, I'm not sure how I will be able to get power to the 3 drives, let alone the other 4 I plan to add down the line. Every port on the PSU is occupied with the exception of CPU2, VGA1, and VGA2. Can I purchase extra SATA power cables from EVGA and just plug them in these extra unused ports?

An alternative that I saw was perhaps getting one of these: SATA Power Splitter
I would get this but...how many drives can be daisy chained like this? I believe my PSU came with 3 daisy-chained SATA power cables, each cable could power 3 drives for a total of 9 drives able to get power. Could I use this to extend the daisy chain? I guess what I'm asking is, how many drives can I actually get away with daisy chaining? Is there an alternative that I'm missing?

Also, what is the recommended RAIDZ configuration, assuming I only have 11 drives to work with at the moment? Should I try 6 drives in RAIDZ2 and 4 in RAIDZ1, or maybe 11 in RAIDZ3?

Build:
Chassis: Rosewill 4U RSV-L4500U Rackmount Server Chassis
Power Supply: EVGA SuperNOVA 850 P2 850W
RAM: 2x 16GB Kingston KSM24ED8
CPU: Intel Xeon E-2236 Hexa-core
Motherboard: Supermicro Motherboard MBD-X11SCA-F-O
HDD: 11x Seagate Exos X16 14TB
HBA: LSI SAS9340-8i ServeRAID M1215 12Gbps SAS HBA

 

[Spearfoot]

Below is my current build, already assembled. I currently have 8 drives installed, 14TB each. I plan to add 3 more next week. In the future (when HDD prices drop or there is another sale), I'll
Currently, all 8 drives are connected to the 8 onboard SATA ports on the motherboard. I have purchased an LSI SAS9340-8i to handle the rest of my drives as they come (hopefully it will have the bandwidth).
The problem is...when my LSI HBA comes in the mail, I'm not sure how I will be able to get power to the 3 drives, let alone the other 4 I plan to add down the line. Every port on the PSU is occupied with the exception of CPU2, VGA1, and VGA2. Can I purchase extra SATA power cables from EVGA and just plug them in these extra unused ports?

An alternative that I saw was perhaps getting one of these: SATA Power Splitter
I would get this but...how many drives can be daisy chained like this? I believe my PSU came with 3 daisy-chained SATA power cables, each cable could power 3 drives for a total of 9 drives able to get power. Could I use this to extend the daisy chain? I guess what I'm asking is, how many drives can I actually get away with daisy chaining? Is there an alternative that I'm missing?

Also, what is the recommended RAIDZ configuration, assuming I only have 11 drives to work with at the moment? Should I try 6 drives in RAIDZ2 and 4 in RAIDZ1, or maybe 11 in RAIDZ3?

Build:
Chassis: Rosewill 4U RSV-L4500U Rackmount Server Chassis
Power Supply: EVGA SuperNOVA 850 P2 850W
RAM: 2x 16GB Kingston KSM24ED8
CPU: Intel Xeon E-2236 Hexa-core
Motherboard: Supermicro Motherboard MBD-X11SCA-F-O
HDD: 11x Seagate Exos X16 14TB
HBA: LSI SAS9340-8i ServeRAID M1215 12Gbps SAS HBA

Hmmm... 16 drives may be too many for an 850W power supply.

Here's a good resource to review regarding power supplies, that should help you figure this out:

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

 

[Crusher21]

Hmmm... 16 drives may be too many for an 850W power supply.

Here's a good resource to review regarding power supplies, that should help you figure this out:

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

Good read! On second thought, looks like 12 drives would probably be the most I could reasonably power with my current PSU (I just bought it so I'm not really looking to replace it just yet lol).

But still, what is the proper method for getting power to these drives? Are the extra VGA1/VGA2/CPU2 slots usable for this? Can I add a daisy chain to the already daisy-chained cables that came with the PSU?

 

[jgreco]

Once you get into the 1000W+ PSU range, the rules from the PPSSG thread become somewhat squishier because there is less of a risk of all your drives spiking in current at exactly the same time. It's actually preferable to start looking at things like staggered spinup.

Only EVGA will be able to tell you for certain if their VGA or CPU power plugs may be used for extra hard drives. This is really somewhat dependent on the design of the PSU. The general answer is "it should probably be able to", but depending on the particulars, it might be a bad idea, and you really need an opinion informed by the facts of the design. All sorts of other things can also goof this up in nonobvious ways, such as the amp ratings of plugs or cables.

 

[dak180]

But still, what is the proper method for getting power to these drives? Are the extra VGA1/VGA2/CPU2 slots usable for this? Can I add a daisy chain to the already daisy-chained cables that came with the PSU?

Only EVGA will be able to tell you for certain if their VGA or CPU power plugs may be used for extra hard drives. This is really somewhat dependent on the design of the PSU. The general answer is "it should probably be able to", but depending on the particulars, it might be a bad idea, and you really need an opinion informed by the facts of the design. All sorts of other things can also goof this up in nonobvious ways, such as the amp ratings of plugs or cables.

My guess almost certainly not since those plugs should only be suppling 12v and any HDD needs both 12v and 5v (and in rare cases can use 3.3v instead of 5v). @jgreco is correct though that only the manufacturer can tell you for sure since the plugs on the power supply are not standard. I cannot imagine a reason for them to have them wired for anything other than 12v though.

16 drives is really at the point where I would think you are likely better off with a case that includes a backplane for your drives and (among other things) handles the power distribution / transformation issues for you.

 

[ChrisRJ]

16 drives is really at the point where I would think you are likely better off with a case that includes a backplane for your drives and (among other things) handles the power distribution / transformation issues for you.

I agree. My current FreeNAS box has 8 spinning drives plus 2 SSDs and in hindsight having gone for a proper server case would have been a good idea. It is not terrible yet, but it has its downsides. Since the case that was chosen by the OP is rack-mount, I would have hoped for some kind of power distribution built in.

 

[Crusher21]

Once you get into the 1000W+ PSU range, the rules from the PPSSG thread become somewhat squishier because there is less of a risk of all your drives spiking in current at exactly the same time. It's actually preferable to start looking at things like staggered spinup.

Only EVGA will be able to tell you for certain if their VGA or CPU power plugs may be used for extra hard drives. This is really somewhat dependent on the design of the PSU. The general answer is "it should probably be able to", but depending on the particulars, it might be a bad idea, and you really need an opinion informed by the facts of the design. All sorts of other things can also goof this up in nonobvious ways, such as the amp ratings of plugs or cables.

At this point I can only see myself having 11 drives. Is it really worth it to return my EVGA 850W Platinum PSU for one of those BeQuiet 1000W Platinum PSU's (which is $20 cheaper too)? Everything is already hooked up, I don't feel like running those cables again unless my current PSU is inadequate.

My guess almost certainly not since those plugs should only be suppling 12v and any HDD needs both 12v and 5v (and in rare cases can use 3.3v instead of 5v). @jgreco is correct though that only the manufacturer can tell you for sure since the plugs on the power supply are not standard. I cannot imagine a reason for them to have them wired for anything other than 12v though.

16 drives is really at the point where I would think you are likely better off with a case that includes a backplane for your drives and (among other things) handles the power distribution / transformation issues for you.

I was really trying to avoid using a backplane because I don't know much about them, and they seemed extremely expensive. It looked like the only way to get a backplane was to go the prebuild/used route.

With my 11 drives, is RAIDZ2 adequate or should I go with RAIDZ3? I will have separate offline backups of my data.

 

[Stux]

FWIW, I use a 1000W PSU with my 24 drive chassis…