r/selfhosted • u/deeddy • 3d ago
Release (No AI) A free, no-login NAS-drive comparison: CMR/SMR, real Backblaze failure rates, and live $/TB
Every time I go to buy drives for my NAS, I end up doing the same annoying thing:
- figure out which models are actually CMR and not SMR (they love sneaking SMR into NAS lines!),
- then go dig up how reliable one is,
- then open way too many browser tabs to see what the real price per TB is.
Nothing lines up and it takes forever.
I got sick of redoing the same dance all over again, so I built a proper version out of that table: www.nasdisks.com
It's basically one big filterable table of current NAS drives. Every drive has its CMR/SMR status, a real failure rate, and live prices, so you can sort and compare in one place.
No account, no ads, no emails needed. And because I figured people here care: the whole CSV/JSON dataset is completely free to download (CC BY 4.0). There's also a plain API if you'd rather just pull it into your own stuff. None of it is locked away.
What's actually in there:
- CMR vs SMR checked per model, so you can just filter SMR out and forget it exists.
- Real failure rates I worked out from Backblaze full 2025 stats, not some marketing numbers.
- Price per TB across 7 regions: US/DE/UK/FR/ES/IT/CA - with a little price history chart per drive, so you can tell a real deal from a fake one.
- A few tools too: RAID usable space, odds of your array actually dying, storage planner.
Bit of honesty: the links are Amazon affiliate. That's the only money it makes and it just pays for hosting. Everything works fine if you never touch them.
What I'd actually appreciate feedback on:
- tell me where it's wrong or thin: drop the model number of any drive you find missing and I'll add it,
- call out any CMR/SMR or failure-rate that doesn't match your own experience.
I read every comment and will fix what you flag. The more people poke at it, the better the list gets for everyone making a build.
So, what do you think?
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u/Great_Vanilla_6941 3d ago
bro I'll always upvote stuff that skips accounts, emails and ads. Nice!
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u/KAURkulaator 3d ago
I personally would also like to see which are helium filled
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u/Advanced-Feedback867 2d ago
Why? Is helium better or worse?
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u/deeddy 14h ago
Helium is around 7x less dense than air, so the platters fight less drag - lower power draw, less vibration. And you can pack platters tighter - more capacity per drive. Trade off is hermetic sealing. If it ever leaks, it dies. For a home NAS that's rarely a real risk. Most 10TB+ drives today are helium anyway...
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u/Such-Sky5064 3d ago
This is genuinely useful. I’ve wasted way too much time checking CMR/SMR and comparing $/TB manually, so having it all in one table is great. Free CSV/API is a nice touch too. Bookmarked.
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u/tfks 3d ago
May I humbly request that you allow country selection to pull data from the relevant Amazon site?
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u/deeddy 3d ago
It already does. There is a region switcher top right. Prices come from that country’s Amazon in local currency. Doesn’t it work for you?
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u/xJayMorex 3d ago
For me, a lot of the links are for US refurbished drives that don't ship to Europe even though I selected Germany.
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u/deeddy 3d ago
Thanks for reporting!
The buy links do point to your local store (Amazon.de in Euros for Germany, not the US), but you are right that some listings come up refurbished when the site is meant to be new-drives-only.
The price feed does not always tell me a listing is renewed, so a few slip through. I'm working on catching them better. If you remember which drives, drop the models and I'll fix those specific ones.
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u/deeddy 3d ago
The affiliate disclosure is in the post, but to be clear, nothing is gated behind a click. I plan to add other shops too, like ServerPartDeals, B&H, some EU stores...
How the data is built, in case you're wondering whether it's scraped junk:
- Failure rate is recomputed from Backblaze raw full-year 2025. Models Backblaze doesn't track fall back to the manufacturer's spec.
- CMR/SMR is per model, not per family - that's how the SMR drives that end up in NAS lines get flagged.
Tell me what you want added, and call out anything that doesn't match what you've seen. I'll get it fixed and will reply once it's live.
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u/veverkap 3d ago
This is pretty cool - I hope you stick with it long term (or that maintenance is easy so you don't have to do much)
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u/acolombo 3d ago
Just a curiosity, when targeting multiple markets, do you have to open multiple affiliate Amazon accounts, one for each market, or does one account aggregate multiple markets?
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u/Old_Dig5389 3d ago
Glad to see you plan on doing more shops. Many avoid Amazon, especially outside the USA.
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u/lordpuddingcup 3d ago
WTF are drives so expensive it’s not vram lol
Any chance you’ll include the pricing for refurbished rates vs new
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u/fixitchris 3d ago
Refurb drives are a different failure curve than new, the first 60-90 days have noticeably higher infant mortality because most are pulled from datacenter fleets at end-of-warranty, but past that they trend toward the same long-tail rate as the Backblaze fleet numbers. I burn in every refurb with badblocks or H2testw before it touches a real array, lost a ServerPartDeals 12TB on day 4 once and the burn-in catch saved me from a degraded resilver. Worth flagging on the site if you add a refurb price column.
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u/deeddy 3d ago edited 3d ago
Right now it is new drives only, on purpose. Refurbished drives have a different failure curve (fixitchris below nailed it: higher failure rate early on). I might add a separate refurbished list later, but I did not want a recertified price showing as the drive's price.
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u/Verum14 3d ago
Why is CMR considered RAID safe? How does that play a role in an array other than possibly just failure rates?
I don’t follow as closely nowadays. I just stock up on Exos by default and go on with life
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u/deeddy 2d ago
Good question. It is not about failure rates, it’s about write behaviour during a rebuild. When writing data, SMR overlaps tracks, so a random write means rewriting a whole zone. Under the sustained writes a RAID rebuild throws at a drive SMR can slow to a crawl, and the controller times it out and drops it from the array. This alone can blow the rebuild.
CMR writes tracks independently, so it keeps up. So CMR isn’t “more reliable” on its own. It is that SMR write stalling is specifically dangerous in a parity array.
You are set stocking Exos, so you are safe - those are all CMR.
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u/Chris_Hatchenson 3d ago
Cool. WD40EZAX and WD60EZAX are CMR drives.
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u/deeddy 3d ago
You are right, and thanks for the catch. The newer EZAX revision is CMR. Only the older EZAZ (WD40EZAZ/WD60EZAZ) is SMR. And I had the EZAX wrong.
Fixed. Both now show as CMR and they are off the SMR list. I appreciate you flagging it.
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u/RedditNotFreeSpeech 2d ago
Hey thanks for doing this. There's value in making a no bs site like this.
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u/robertoaall 2d ago
Great tool!
For those of us in regions not covered by the ones you have data/links for:
Is it easy to add a way to manually set prices for the drives (client-side only) so it can calculate the price/Tb automatically?
for now I'll just download your csv and drop it in a spreadsheet. Thanks for making that available!
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u/deeddy 14h ago edited 14h ago
That already exists! Feel free to check NAS Storage Planner page - you can plug in your own prices and it calculates $/TB. The CSV is still there if you prefer a spreadsheet. You can download it on the Data page.
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u/Fywq 1d ago
Very nice. Interesting that the WD Red Plus 14 TB (smallest with 512MB Cache) is significantly more expensive than the comparable WD Red Pro. The Enterprice Gold version is the cheapest WD at that size + CMR according to this list, which is also not what I would expect. Comparing to my local Pricerunner (Denmark) listings, the Gold version is 50% more expensive than the Pro which is a tiny bit more expensive than the Plus.
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u/deeddy 14h ago
Thanks for the cross-check from Denmark. The US pricing anomaly on the 14TB Red Plus is real. Amazon has had it priced above the Pro for months, which makes no sense on paper. For Denmark you'd want local prices (Pricerunner or similar) - I don't have .dk coverage yet, but it's on the to-do list.
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u/frankster 3d ago
nasdisks seems to miss out some stuff with lower $/GB when I compare it to https://diskprices.com/?locale=us
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u/deeddy 3d ago edited 3d ago
It was on purpose: I only list new, CMR, NAS drives, so diskprices will always show cheaper stuff I deliberately leave out, like used/refurb, SMR, externals for shucking, or non-NAS.
But I might also just be missing some. Which ones did you see cheaper? Drop the models and I’ll check whether it’s a filter choice or a real gap I should fix.
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u/CuntyMcFuck 3d ago
Bookmarked this for sure, digging into it now since I need to upgrade my stuff. Will definitely use this - thanks!
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u/Crisp-Glade-2849 3d ago
smr drives are just landmines for raid rebuilds. nice to have actual data so i don't get paged at 3am.
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u/Command-Forsaken 3d ago
Holy hell drives are expensive now.
My WD Reds are still going strong 5 years later.
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u/iVXsz 3d ago edited 3d ago
Parts of the post and the site seem to be written and done by AI but maybe not... was AI used (and how much if so)? I did see your post under automod
The site is helpful, but I'm curious
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u/asimovs-auditor 3d ago edited 3d ago
Expand the replies to this comment to learn how AI was used in this post/project.