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First unraid build

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Hello unRaid community,


I am about to create my first unraid server out of my old PC.


- Case: Nanoxia Deep Silence 5 Rev. B
- Mainbord: MSI Z170A Gaming M3
- CPU: i7-6700K
- CPU Cooler: be quiet! Dark Rock Pro 2
- RAM: Corsair 16GB (2x8) DDR4-3000 (not ECC)
- GPU:  MSI GTX 1080
- PSU: be quiet! Dark Power Pro 650w

- 4 x 16 TB IronWolf Pro (2 for Parity)


Aside from raw storage, I will only use Plex.
Do I need the GPU for anything else but Plex/ can I just add it later?

(I will use the GTX 1080 in my new PC until the RTX 3080 Ti becomes is available)

Would you suggest I get ECC Ram and if so, how much?

Should I get and M.2 SSD for Cache or is that not really necessary just for storage.

Which HBA should I get?



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The 6700K has iGPU and it's powerful enough to transcode so you don't even need a GPU for Plex unless you are doing a serious number of concurrent streams (or multiple 4k streams).


ECC RAM is not necessary so if your focus is to reuse parts then there's no need to obtain ECC.

On your current RAM, do NOT overclock. Your memory spec is certified overclock so it is an overclock nonetheless. Run it at 2133MHz, in short.


Your server with Plex is certainly "not for storage" because Plex is not a storage functionality / app.

With Plex, you should have an SSD cache for appdata, docker image (or vdisk + libvirt image if you go the VM way).

Does not have to be M.2 (NVMe). It can be SATA.


Whatever SSD you get for cache, go for 3D TLC (or 3D NAND or V-NAND or terms to that effect) and avoid DRAM-less SSD like the plague.







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I don´t think I will find the the time setup Plex in the foreseeable future, maybe next year.

It will be used by two TV´s max, probably not in 4k though.

Since I don´t need it, I will sell it after I buy one of the new RTX 3000 series.


My focus is not really on reusing existing parts, I just want a reliable way to store my data.

From most of what I read so far about FreeNas, the conclusion I got was ALWAYS use ECC RAM for storage.

Some even said it is the most important thing to above everything else.

Also, it is quite cheap, considering that I am about to spend 2.000 € on Harddrives.

Having a secure system that will last me for years is defently more important to me than saving a few bucks.


How much RAM should I have in total, this 1 GB RAM / 1 TB Storage seems a bit much.

Do I even need a Cache drive for now, or should I just add it later when I install Plex?

And how big should the Cache drive be?

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FreeNAS uses ZFS (RAID) which is fundamentally very different from Unraid so there is really very few, if any parallel in terms of system requirements.


While any RAID-based implementation (not just ZFS but also BTRFS, which Unraid uses for its cache pool) is sensitive to memory corruption, ZFS is even more susceptible due to the difficulty (or impossibility?) in restoring from a corrupt pool.

The 1GB RAM / 1TB storage is an old wives' tale. If you don't use deduplication feature then you don't need that much RAM. If you do use deduplication feature then depending on your config, you may need way more than that. The 1G/1T is just so easy to remember that it has taken on a life of its own.


In contrast, you probably can think of the Unraid array like a combination of mergerfs and snapraid. It pools data from individual drive (which each has its own file system) and calculate parity bits for such data. And as a result, there are way fewer scenarios (if any?) that would cause you to lose the entire pool (that you would otherwise not had you use ECC RAM - remember there's a limit to what ECC can correct!), as compared to ZFS.


There is an argument for ECC RAM that it just helps with overall stability of the system.

While I agree with that point from the theoretical standpoint, from my own actual experience though, having used both ECC and non-ECC, I have not seen any significant diff in system stability.

I think it's more likely than not that a lot of the instability diff is more attributable to overclocked RAM (including certified overclock i.e. higher-than-stock speed that a manufacturer says your RAM is capable of running at) than ECC vs non-ECC.





Now for the Unraid server, if you indeed just use it as a NAS, 4TB (or even 2TB) RAM is enough.

You 6700K is a massive overkill with that usage though.


And you can skip on the cache drive until you actually need it.

Unraid cache is strictly only for write caching, which was important back when reconstruct write (aka "Turbo Write") wasn't a thing.

With HDDs that came out in the last 5 years or so + turbo write, cache drive is very much an optional thing for a NAS-only build.

One thing to keep in mind is that Unraid will never be as fast as FreeNAS (ZFS), both in the read and write departments. The best performance you get will never be faster than the fastest drive in the array for read and never be faster than the slowest drive in the array for write.




Btw, for your 4x drive array, having 2x parity is a massive overkill for general media storage, unless your media is the only digital copy of Casablanca or something to that effect.

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Ok, so I will just use everything as is and set the RAM to 2133MHz.

Or is there anything I should change?

And what HBA should I use for the drives?

Can I mix the drives conections, e.g. some attached to the mobo and some to an HBA?

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1 hour ago, Aussie said:

Ok, so I will just use everything as is and set the RAM to 2133MHz.

Or is there anything I should change?

And what HBA should I use for the drives?

Can I mix the drives conections, e.g. some attached to the mobo and some to an HBA?

Yes, just run your RAM at 2133MHz would be safest.


In terms of HBA, any LSI HBA would be good but you should do a search on forum for johnnie.black topic.

He did a speed test of various adapters (which obviously work with Unraid) which I found really useful.

Whatever you get, do NOT get anything with Marvell controller.


You can freely mix HBA and mobo, with some exceptions such as

  • Some HBA does not support TRIM so you shouldn't connect SSD to those controllers
  • Your HBA speed maybe bottlenecked (e.g. running an x8 controller on an x4 electrical) so you may need to reduce number of connected drives to such controller
  • Obviously SAS drives can't be plugged onto motherboard SATA (obvious but someone *cough* I *cough* made that same mistake - PS: it's not COVID-19 cough)
Edited by testdasi

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