Scoring methodology

WorthaByte attaches three independent scores to every drive. None is a black box — each is computed from named, citable factors so you can always see exactly why a drive rates the way it does.

NAS-Safe Score (0–100)

Rates how suitable a drive is for 24×7 multi-bay NAS / RAID use. It is additive: each factor contributes up to a fixed number of points, and the factors sum to 100. Unknown inputs receive neutral partial credit rather than a guess, and lower the result’s confidence instead.

FactorMax pts
Recording technology (CMR vs SMR)
The single most important NAS fact. SMR drives can stall RAID rebuilds with write-amplification, so SMR scores 0 here and is hard-capped at the “Use with caution” band no matter what else it earns.
35
Vendor NAS endorsement
Whether the manufacturer explicitly markets the drive for multi-bay NAS. Enterprise drives that work in a NAS but aren’t marketed for it lose these points.
15
Rotational-vibration (RV) sensors
RV sensors keep performance stable when many drives vibrate together in one chassis — important for multi-bay arrays.
15
Rated annual workload
Manufacturer TB/year rating. 550 TB/yr (enterprise/Pro) earns full marks; 180 TB/yr (consumer NAS) earns most; lower earns partial.
15
MTBF rating
Mean time between failures. 2.5M hr (enterprise) is full; 1.0–1.2M hr (consumer NAS) is most; unknown is scored with neutral partial credit, never guessed.
10
Warranty length
Longer coverage signals manufacturer confidence and lowers ownership risk. 5 years full, 3 years most.
10
Total100

Bands

  • 85+ Excellent for NAS
  • 70+ Good for NAS
  • 50+ Use with caution
  • 0+ Not recommended for NAS

Hard rule: an SMR drive can never rate above “Use with caution,” regardless of its other strengths.

Every drive page shows a “Why this NAS-Safe score?” breakdown with the per-factor points and the sources behind them.

DealScore (0–100) — price rating for one drive

Answers one question: “Is the current price good right now, for this drive?” It is purely price-driven and use-case agnostic. Two signals are blended:

  • Historical position (60%) — where today’s price-per-TB sits within this exact listing’s own price history. Cheapest-ever scores best.
  • Market position (40%) — where today’s price-per-TB sits against every comparable listing for the same drive. Cheapest in the field scores best.

Both signals are intra-drive: the drive’s own history, and the other listings of that same model. So a DealScore never says a drive is good value against a different drive — a niche model that is permanently overpriced can still score well by dipping against itself. That is why every price badge is labelled “for this drive”, and why cross-drive value is a separate badge (below).

The blended score maps to a price rating — not an overall buy recommendation. Whether a drive fits your use is a separate question (see the NAS-Safe Score, condition, and Seller Risk):

  • 80+ Great price · 60+ Good price · 35+ Average price · <35 Overpriced

Guardrails: high seller risk or an unverified condition caps a “Great price” rating down to “Good price.”

When a listing has neither a usable price history (fewer than three tracked points) nor a single comparable competing listing, there is nothing to rate. Rather than publish the neutral 50 the maths falls back to — which would read as “average price” — we show “Not enough data to rate” and keep the listing out of every “best deal” list.

$/TB rating — value against other drives

The cross-drive counterpart to DealScore. It places a drive’s cheapest live price-per-TB among every other tracked drive of the same capacity: cheapest quarter reads Cheap $/TB, dearest quarter Pricey $/TB, the middle half Typical $/TB.

Capacities are compared separately on purpose. Price per terabyte is structurally higher on small drives, so ranking a 4 TB drive against the whole catalog would report a fact about capacity rather than about the deal.

We only publish a rating when at least four drives of that capacity are tracked — below that a single outlier would swing the verdict, so no badge is shown. Flagged and price-outlier listings never set the prices a peer group is measured against.

Seller Risk (0–100, or not applicable)

Captures the uncertainty of who you’re buying from. First-party and single-seller storefronts (ServerPartDeals, GoHardDrive, B&H, Best Buy) carry no per-seller reputation gamble, so Seller Risk shows as not applicable for them.

For the one open marketplace we track — eBay — Seller Risk is a real 0–100 score (higher = riskier), computed from the listing’s condition plus the seller’s feedback percentage andfeedback volume. Listings below a 98% positive / 50-rating floor aren’t shown at all. If a marketplace listing has no feedback data available, Seller Risk reads “not evaluated”rather than a number.

Privacy: WorthaByte does not store eBay seller identities (usernames) — only the anonymized feedback aggregates the score needs. We surface reputation, never identity.

Data sources (47 drives researched)

NAS-Safe inputs are hand-curated and citable. Each researched drive below links to the manufacturer source(s) its specs were verified against. A drive is only eligible for a public NAS-Safe Score once at least one real source is confirmed.

Scores are decision aids, not guarantees. Always confirm specs and condition with the retailer before purchase.