Only if you define the word 'speed' before you sign, because tender documents almost never do, and that's where good bids lose. 'Write speed' can mean a burst figure that lasts two seconds or a sustained figure over a full 50GB transfer — and they're often four times apart. Define the method, the volume and the population, and the number becomes something you can both sign and prove.
You can promise a minimum write speed only after you and the buyer agree what 'write speed' means: which speed (sustained, not burst), over what volume (a continuous write, not a 1GB file), measured how, and on what population of units. Put those four into the tender response as a defined test, backed by a per-batch report and a remedy if a batch fails. A number without a method is a liability you'll be asked to defend at acceptance — and most tender failures on speed are failures of definition, not of the drive.
The short answer
You can promise a minimum write speed — but only after you and the buyer agree what “write speed” means. Tender documents almost never define it, and that gap is where good bids lose.
A tender line that reads “minimum write speed 40MB/s, supported by a manufacturer test report” looks complete. It isn’t, because “write speed” can mean a burst figure that lasts two seconds or a sustained figure over a full 50GB transfer — and those are often four times apart. If you sign against the first and the buyer inspects against the second, you fail a drive that’s perfectly good, or pass one that isn’t.
So the work isn’t promising the number. It’s defining the word.
Why “speed” has no single meaning
Three measurements, one word:
| Measurement | What it is | Typical value |
|---|---|---|
| Burst write | Short write into cache | High — looks great on a datasheet |
| Write with cache | First seconds of a transfer | Mid |
| Sustained write, cache exhausted | Continuous write to a full drive | A fraction of burst |
A 1GB file fits in cache and measures the burst. A 50GB library doesn’t, and runs at the sustained rate for 95% of the transfer. A tender that doesn’t say which one it means has asked a question with four possible answers.
For any drive that writes real data, specify sustained, cache exhausted, over a stated volume. That’s the number that predicts field behaviour.
What to write into the tender response
Four fields turn an ambiguous clause into a testable one:
| Field | Example | Job |
|---|---|---|
| Metric | Sustained write | Excludes cache-assisted burst |
| Volume | Continuous 4GB write | Long enough to exhaust cache |
| Method | Named tool and settings | Reproducible |
| Population | Per unit, or defined sample | Says what’s guaranteed |
Add a remedy — replacement, credit, or batch rejection if a defined share fail — and the number becomes enforceable rather than decorative.
The three documents, and why they’re different
Tenders usually list “datasheet, test report, or manufacturer confirmation” as if interchangeable. They aren’t.
| Document | Asserts | Used for |
|---|---|---|
| Datasheet | Design intent, in ranges | Bidding |
| Test report | Measured results on specific units | Proving at acceptance |
| Written confirmation | An undertaking to meet the figure | Enforcing the contract |
The test report is the one that carries weight: it names units, a method, a date and a result. A datasheet with a letterhead is not a report. A manufacturer’s confirmation without a report is a promise without evidence.
And ISO 9001 — often requested as a qualifying document — says the factory has a quality system. It says nothing about any drive’s speed. File it as evidence of process control, not of product performance.
Per-capacity traps
A tender that sets one minimum across 32GB to 256GB has either set it at the slowest unit or silently excluded some capacities, because sustained write scales with the number of memory dies in parallel. Within one family, the 32GB drive sustains far less than the 256GB one.
If the tender sets rising minimums per capacity, the requirement is well constructed and you can meet it precisely, per capacity. If it sets one number, ask which capacity it applies to — the answer tells you whether you’re bidding a real spec or a vague one.
A scenario: the bid that lost on a definition
A buyer bidding a public contract quotes 64GB drives at a sustained 40MB/s, which the drives meet. The acceptance test, run by the buyer, uses a 1GB file and reads the burst rate — which is 90MB/s on the same drive, but the buyer’s inspector flags “inconsistent with datasheet” because the datasheet quoted burst and the bid quoted sustained.
Nobody lied. The tender never said which one. The bid lost on a definition the bidder didn’t pin down.
The fix was a one-line clarification in the bid: “Speed quoted is sustained write over a continuous 4GB transfer; burst figures are not used for conformance.” Same drives, same price, no ambiguity to lose on.
What to ask before you bid
- Does the tender define burst or sustained?
- Over what volume — a 1GB file or a continuous write?
- With what method, and on what population of units?
- Per capacity, or one number across all?
- What’s the remedy if a batch fails the defined test?
- Did I provide datasheet, report and confirmation — each doing its own job?
Define the word before you promise the number. Most tender speed failures are failures of definition, not of the drive.
Sources
Frequently asked questions
The tender just says 'minimum write speed 40MB/s'. What do I actually promise?
As written, you promise nothing you can defend, because the word 'speed' is undefined. Before you sign, clarify whether it means burst or sustained, over what file size, and on how many units. If the buyer won't clarify, define it yourself in your bid as 'sustained write ≥ 40MB/s over a continuous 4GB write, per unit' and state that this is your interpretation. A defined number you can meet beats an ambiguous one you'll be challenged on at incoming inspection.
Burst vs sustained — which should the tender specify?
Sustained, every time, for any drive that writes real data. Burst figures measure a short write into cache and are three to four times higher than sustained. A tender that grades on burst is measuring the wrong thing and will reject good drives or accept bad ones depending on which the supplier quoted. For tenders, ask for 'sustained write, cache exhausted, over a stated volume' — that's the number that predicts field behaviour.
What documents does a tender usually want for speed?
Three, and they're not the same: a datasheet (design intent), a test report (measured results on specific units, named method and date), and a manufacturer's written confirmation (an undertaking to meet the figure, with a remedy). Tenders often list these as alternatives; the test report is the one that proves, and the written confirmation is the one that enforces. Provide all three, each doing its own job.
Can different capacities have different minimum speeds?
Yes, and a well-built tender sets them per capacity, because sustained write scales with how many memory dies work in parallel — a 32GB drive and a 256GB drive in the same family can differ two or three times. A tender setting one number across all capacities is either setting it at the slowest (32GB) or silently excluding some capacities. Ask which capacity each minimum applies to.
What happens if a delivered batch fails the speed test?
Whatever the contract says — so write it before you bid. Define an acceptance test with a method, a sample size, a remedy (replacement, credit, or rejection of the batch), and a window to run it. Without those, a failure becomes a negotiation in which the supplier argues the method and the buyer argues the result. Defining the method up front is what makes the guarantee usable.
Is ISO 9001 evidence that the drive writes at the stated speed?
No. ISO 9001 says the factory has a documented quality system; it says nothing about any particular drive's speed. Tenders list it as a qualifying document, which is fine, but treat the certificate as evidence of process control, not of product performance. The test report is what predicts what arrives in the box.