marshalf/nas-drive-data
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

price-trends: add sale-frequency data (how often drives discount)

Browse source 
Per-model and weekly computed figures: how often each current 8TB+ drive
goes on sale (best price 5%+ below its own rolling-median baseline) and how
deep. NAS lines discount several times more often than enterprise; similar
depth. Computed values only, compiled from Amazon price history.
This commit is contained in:
deeddy 2026-09-16 23:32:27 +02:00
parent b73e01e1d3
commit df733199b4
3 changed files with 193 additions and 2 deletions
Download patch file Download diff file Expand all files Collapse all files

12
price-trends/README.md
View file

@ -10,9 +10,17 @@ The chart below tracks both tiers from Jul 2024 to the latest month. Prices held
Median price-per-TB sat flat around $20/TB through 2024 and most of 2025, then roughly doubled to the mid-$40s/TB from late 2025, and has held there since. Both tiers moved together: among new drives, enterprise is not the price-per-TB bargain it's assumed to be, and both got hit about equally. The usual driver is the AI datacenter buildout pulling high-capacity nearline supply.
## Sale frequency
A companion view, in [`sale-frequency-by-model.csv`](sale-frequency-by-model.csv) and [`sale-frequency-weekly.csv`](sale-frequency-weekly.csv): how often each current drive actually goes *on sale*, and how deep. For each day we compare a drive's best price to a centred rolling median of its own recent price, so a genuine dip counts but the long price climb is not mistaken for a discount, then count the days sitting 5%+ below that baseline. Same scope as the $/TB series: 8TB and up, US, new in-stock prices, compiled from Amazon price history.
NAS drives (WD Red / IronWolf class, including the Pro lines) go on sale several times more often than enterprise/datacenter drives - roughly one day in ten vs one in forty - though the cut is about the same size when it happens (~10% typical, ~30% at the deepest). Seagate IronWolf Pro goes on sale most often; Exos and Ultrastar barely move. Interactive weekly chart + sortable table: [nasdisks.com/articles/nas-drive-sale-frequency](https://www.nasdisks.com/articles/nas-drive-sale-frequency/).
## Files
- [`monthly-median-per-tb.csv`](monthly-median-per-tb.csv) - columns: `month`, `consumer_usd_per_tb`, `enterprise_usd_per_tb`. Computed monthly medians only.
- [`sale-frequency-by-model.csv`](sale-frequency-by-model.csv) - per drive: `brand`, `line`, `capacity_tb`, `segment` (`consumer` = NAS lines incl. Pro, `enterprise` = datacenter), `pct_days_on_sale`, `typical_discount_pct`, `deepest_discount_pct`, `sale_events`, `days_observed`.
- [`sale-frequency-weekly.csv`](sale-frequency-weekly.csv) - weekly share of tracked days on sale per tier: `week_start`, `consumer_pct_days_on_sale`, `enterprise_pct_days_on_sale`.
## Interactive version
@ -25,7 +33,7 @@ For each month, take each drive's average price-per-TB across its logged days, t
8TB and up because small drives carry a much higher price-per-TB (fixed per-drive costs spread over less capacity), and which small SKUs happen to be in stock would swing an all-capacity median for reasons unrelated to prices actually moving.
This folder publishes the computed monthly medians only, not the underlying per-drive price observations.
This folder publishes computed statistics only (monthly medians and the sale-frequency aggregates), not the underlying per-drive price observations.
## Takeaway for buyers
@ -33,4 +41,4 @@ Because the two tiers track each other, there's no reliable price-per-TB win fro
## Using this data
The monthly medians here are free to use, with a credit to `nasdisks.com` (a link back is appreciated). They are computed aggregate statistics, provided as-is, and separate from the repository's CC BY 4.0 license, which covers the drive specs and CMR/SMR data.
The monthly medians and sale-frequency figures here are free to use, with a credit to `nasdisks.com` (a link back is appreciated). They are computed aggregate statistics, provided as-is, and separate from the repository's CC BY 4.0 license, which covers the drive specs and CMR/SMR data.