do HDD manufacturers guarantee performance?

[Numbat]

Does anyone know if HDD performance is guaranteed with respect to throughput? I can't seem to find any documentation regarding specifications in terms of performance guarantees. Nothing like min/max/avg read/write etc +/-10%

For example, say your HDD only achieves 60% (and performance is sporadic; benchmarks look like a seismic graph) of what some reviews achieved for read and write throughput, and you've ruled it down to being/isolating the drive at fault. However, using the disk manufacturer's diagnostic utility, there are no bad sectors.

Is this considered faulty in these circumstances or is seeking a replacement like getting blood out from a stone?

[f1y]

if I wasn't happy with my drive I would send it back. :) as for do they actually cover that.. I haven't a clue.

Maybe there's a known problem with the drives, and they'll exchange it. If the drives new It may be easier getting a replacement from the store rather then the manufactuer.

[Menelmarar]

Never had to, but drive manufacturers do publish performance numbers themselves. Latency, transfer rate, etc.
For example:
http://westerndigital.com/en/library/sata/2879-001144.pdf

Call their support line and complain. Report back if they help you :)

[Numbat]

Thanks.

I have a ticket open with WD to see if it is just something like firmware. Otherwise the retailer will probably be the next port of call.