Looking for an honest Asustor Flashstor 6 vs Synology DS1821+ comparison in 2026? We scored both nas storage on the same six-dimension framework — performance, battery, display, camera, design and value — using identical methodology, so the numbers below are directly comparable. In our overall scoring the Synology DS1821+ comes out ahead 50/100 to 55/100 — a 5-point gap. The widest gap is in performance, where the Synology DS1821+ pulls noticeably ahead. On price the Asustor Flashstor 6 undercuts the Synology DS1821+ by 14% ($699 vs $799), which materially changes the value calculus for budget-conscious buyers.
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Synology DS1821+ narrowly beats the Asustor Flashstor 6 in the nas storage category, especially in performance, scoring 55 vs 50. If you want the better overall nas storage, Synology DS1821+ is the recommended choice.
Picking Synology DS1821+ over Asustor Flashstor 6 means trading these off.
Specs are roughly matched — winner decided on overall scoring, not a specific spec advantage.
✓ Pros
✗ Cons
✓ Pros
✗ Cons
| Spec | Asustor Flashstor 6 | Synology DS1821+W |
|---|---|---|
| Price | 699$✓ | 799$ |
| RAM | 8GB✓ | 4GB |
| OS | ADM 4.0 | DSM 7.2 |
| Weight | 1100g | 1100g |
| Dimensions | 250 x 220 x 220 mm | 260 x 193 x 166 mm |
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Buy Asustor Flashstor 6 if…
Choose the Asustor Flashstor 6 if budget is your top priority — it offers competitive specs at a lower price point.
Buy Synology DS1821+ if…
Buy the Synology DS1821+ if you want the best performance in this comparison. It scores higher overall and is the recommended choice for most buyers.
Synology DS1821+ narrowly beats the Asustor Flashstor 6 in the nas storage category, especially in performance, scoring 55 vs 50. If you want the better overall nas storage, Synology DS1821+ is the recommended choice.
No, Synology DS1821+ scores higher (55 vs 50).
Asustor Flashstor 6 is cheaper at $699 vs $799 for the Synology DS1821+.
Choose the Asustor Flashstor 6 if budget is your top priority — it offers competitive specs at a lower price point.
Buy the Synology DS1821+ if you want the best performance in this comparison. It scores higher overall and is the recommended choice for most buyers.
Asustor Flashstor 6 has more RAM (8GB vs 4GB), which helps with multitasking.
Reviewed by VersusMatrix Editorial Team
Last updated: June 1, 2026
Methodology: AI-powered analysis of technical specifications from manufacturer data. Scores are calculated by comparing products across multiple dimensions and normalized relative to the full category database. Our editorial process is independent and not influenced by affiliate partnerships.
Scores are relative within the nas storagecategory. Percentages show each dimension's weight in the overall score. A difference of less than 0.5 points is considered a tie.
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