Staggered spin up

[Pitfrr]

Hello,

I thought I'd give some feedback on my experience with staggered spin up for hard disks.

I have the following test set-up:

Code:

Motherboard: AsRock C2750
Memory: 2 x 8GB PC3-12800 ECC (Kingston KVR16E11/8)
3 x 1TB HDD (Seagate barracuda 7200.12 and Samsung HD103UJ)
3 x 320GB HDD (Seagate barracuda 7200.10)
FreeNAS 9.2.1.8 

The motherboard supports staggered spin up for the disks (at least for 6 out of the 12 possible).
Since on this set-up I'm a bit short on the power supply (I'm using a picoPSU) I thought I'd use this feature to avoid a current surge at boot. And it's a test set-up so it's a good reason to try out. ;-)

At first I configured it in the BIOS but... it didn't work, the disks were always starting all together.

Then I looked deeper into how staggered spin up was working and found out that it is triggered by the pin 11 on the SATA power supply connector.
Unfortunately on consumer grade power supplies, the pin 11 of the SATA power connector is mostly connected to the ground. To enable staggered spin up it must be left floating.

So two possibilities:
- get a compatible power supply
- find a way to get the pin 11 floating

As mentionned I'm using a picoPSU and I don't plan to change for this set-up so I went for the second option... I wanted to find a non destructive/non permanent solution (i.e. taking the pin 11 out of the connector or something like that).

The solution I found was a 1mm wide piece of tape on the pin 11 on the HDD's side.
And it worked like a charm, the six disks are spinning up one after an other.

It's rather a DIY solution but I find it an acceptable solution for a "home" usage.

With the staggered spin-up I reduced the current surge at start-up from 160W (with 5 disks) to 100W (with 6 disks). And without staggered spin-up I couldn't get the system to start with 6 disks.

 

[nightshade00013]

The moral of the story here is this:

Make sure your PSU is properly sized, while the staggered spin up will work for now it is likely running the PSU at near it's limit and at some point in time will go out. If you can only boot the system with a staggered spin up there is ABSOLUTELY no way you can add more drives later on without a PSU upgrade as well.

https://forums.freenas.org/index.php?threads/proper-power-supply-sizing-guidance.38811/
https://forums.freenas.org/index.php?threads/hardware-recommendations-read-this-first.23069/

 

[Mirfster]

Out of curiosity, can I ask why you want/need staggered spin-up?

 

[jgreco]

Out of curiosity, can I ask why you want/need staggered spin-up?

In order to avoid ruining his power supply, presumably. I thought that was explained sufficiently in the OP.

 

[gpsguy]

The OP is using a picoPSU.

Probably something like this - http://www.amazon.com/dp/B005TWE6B8/?tag=ozlp-20

I can't imagine putting 6 disks, with the SATA splitters on one of these PSU's.

Out of curiosity, can I ask why you want/need staggered spin-up?

 

[Mirfster]

In order to avoid ruining his power supply, presumably. I thought that was explained sufficiently in the OP.

I thought I'd use this feature to avoid a current surge at boot.

Ahh, I missed that. Gotcha.

 

[Pitfrr]

@nightshade00013: thanks for the feedback and I do agree with you regarding properly sized power supply.
In fact this is a test set-up with some unorthodox hardware (like the picoPSU) and I wouldn't use it on my main system.

To answer to @Mirfster on why I want/need staggered spin-up:
1- Out of curiosity since the mainboard can handle it, I wanted to check it out and see how to make it work.
2- I wanted to evaluate the picoPSU to see how it behaves with some load (but avoid the current surge for the drive spin up).

I'm using the 150W picoPSU version and I'm also thinking about splitting the 12V rail for further load (i.e. not using the picoPSU to provide the 12V for the HDDs) but I'm not there yet, I'll first continue some testing with this set-up first.

 

[Bidule0hm]

Please note that drives are the most sensitive components in a computer to bad quality power rails (things like voltage sags for example), you can ruin them pretty quickly with a crappy PSU.

PicoPSUs are great in some cases but absolutely not for a NAS.

 

[jgreco]

Please note that drives are the most sensitive components in a computer to bad quality power rails (things like voltage sags for example), you can ruin them pretty quickly with a crappy PSU.

And if anyone ever wonders why I'm so adamant about power supplies being properly sized, there it is, in a single sentence.

PicoPSUs are great in some cases but absolutely not for a NAS.

I'd tend to agree, with some possible wiggle room for 2.5" drives.

 

[Pitfrr]

To feed the picoPSU I'm using a PULS power supply (not for computer use but rather for industrial use, it's a DIN rail power supply) and it should provide a good quality 12V output. I didn't check it out on a scope (I don't have one around) but I'll be paying attention to any unexpected behavior.

Regarding the power supply I'm "playing" around/evaluating what is possible (that's why I didn't develop it more in my original post).