Assembling your first Network-Attached Storage server (or even buying one, for that matter) can be quite exciting. But if you’ve never ventured into the NAS ecosystem, you might encounter differing opinions on practically every topic once you start checking out community forums. And I’m not just referring to the arguments about RAID levels, file systems, network shares, and other advanced NAS aspects, either.

The HDD vs. SSD debate rages in every PC community, including the ones centered around home servers and NAS. If anything, the rise of cheap all-flash systems has made SSDs just as viable for typical file-transfer workflows, while conventional NAS units have started to include dedicated M.2 slots alongside drive bays. And as someone with a proper 3-2-1 backup workflow involving two distinct NAS setups, I don’t consider myself a member of either camp and rely on both SSDs and HDDs on my storage servers.

Hard drives are definitely the better choice for data retention

Slow transfers aside, HDDs are ideal for archiving data

Mechanical HDDs may not possess the blazing-fast transfer speeds of their M.2 adversaries, but it’s hard to deny their advantages in the NAS domain. For starters, HDDs have an amazing TB-per-dollar ratio, making them perfect for RAID-heavy configurations involving dozens of terabytes. If you’re a data hoarder who needs sheer capacity to house archived media, you can find HDDs that go past the 20TB mark. With the massively inflating SSD prices, hard drives are even more viable for high-capacity NAS setups.

But even if you’ve got hundreds of dollars to spare, HDDs are simply better for long-term storage. Since SSDs rely on flash memory cells, they tend to leak charge if you keep them unplugged for a long time – and that’s far from ideal for cold storage tasks and remote NAS units, where you might not even boot the NAS for months. Throw in the limited write cycles on SSDs, and mechanical hard drives are simply better when you want to retain backups for long periods and aren’t too keen on spending hundreds of dollars just to get 2TB of SSDs.

You can set up workarounds to increase their speeds

Depending on your NAS specs, there are a handful of features that can bolster your HDD speeds. Pairing 7200RPM drives with certain RAID levels, for example, can provide a much-needed oomph to your read and write operations. RAID 10 is my preferred solution, as it combines decent redundancy with solid speed, though I suggest avoiding RAID 0 like the plague if you value your NAS data.

If your NAS has some extra memory, you can put it to good use by enabling RAM cache. As a ZFS user, I’ve got Adaptive Replacement Cache configured on my TrueNAS rigs, as it massively bolsters HDD speeds for metadata operations and for reading recently-accessed files. Although ARC isn’t a substitute for SSDs, it’s extremely useful for ZFS-powered rigs housing good ol’ hard drives.

SSDs have their own perks in dedicated NAS setups

They’re perfect as boot drives

When it comes to SSDs, there are plenty of ways you can utilize them in your NAS setup. Leaving Unraid aside (since it’s designed to run off a USB drive), SSDs can house the boot partitions for most NAS distributions under the sun. That way, you won’t have to spend several minutes waiting for your storage server to boot, and can enjoy some extra responsiveness when navigating its UI.

Unless you opt for long-term data storage, SSDs are pretty handy for storage pools where you want better transfer speeds above all else. Assuming your NAS has 5GbE (or better yet, 10G) capabilities, even a PCIe Gen 3 SSD can deliver read/write speeds for editing high-resolution video footage. And as wacky as it may sound, SSD-powered pools are amazing for storing game files, provided you pair them with the iSCSI protocol.

With the RAM armageddon in full swing, an SSD cache might just be more useful than a memory cache. Sure, the latter will be significantly faster in every scenario, but at least you won’t have to sell a kidney just to build a write cache with a 500GB SSD.

Their utility goes up once you dive into the self-hosting rabbit hole

Most pre-built NAS include fairly decent CPUs these days, so there’s a lot you can do with them besides housing documents and backups. Self-hosting is one of these tasks, as the minimal performance footprint of containers makes them perfect for even the weakest NAS units out there.

But unless you’re storing archived media for your containers, housing their data on SSDs will make their UIs pretty responsive. And once you switch to virtual machine workloads, switching to an SSD pool will avoid performance issues of slow hard drives, especially if you want to use distros with desktop environments.

Combining SSDs with HDDs will give you the best of both worlds

I’ve reviewed a bunch of NAS units here on XDA, and hybrid storage servers are my favorite of the bunch. Sure, all-flash NAS units have a tiny footprint and provide better energy efficiency thanks to their SSDs. And in the same fashion, HDD-only servers tend to be somewhat cheaper than their hybrid counterparts. But high-capacity HDDs and blazing-fast SSDs have their own perks in the home lab environment, and it’s always a good idea to arm your NAS with both types of drives.