Comment tester la capacité réelle d'une clé USB à l'aide d'un logiciel gratuit ?

So why do some 64GB USB Flash Drives cost 25 yuan while others are only 15? Beware – you could well be buying a ‘capacity expanded drive’. I’m Mona, from Shenzhen YOUSAN USB flash drive Factory and I’m going to burn my bridges and expose the biggest dark secret in the industry. Let’s use the free, and pretty neat software ‘H2testw’ to find out.

1. Qu'est-ce qu'un "disque d'expansion" ?

What you thought was “fake goods”: Rough casing, no response when you plug it in. No, today’s “capacity-expanded drives” are smarter than that. They are smarter than you think. When you hook a USB drive sold as 64GB into your computer Windows will report: “Available space: 62.5GB”. You can even drop files onto it and the progress bar looks normal! Everything looks perfect. The black tech behind it: Small workshops or rogue manufacturers recycle found 4GB chips. They adjust some controller parameters using mass-production machinery, fooling the whole computer system into displaying as a 64GB device. It’s like a bucket that only holds 4 litres of water getting a sticker slapped on it saying “64 litres” and selling it to you at 64 litres price.

2. Que se passe-t-il lors de l'utilisation de lecteurs d'extension ?

De nombreux acheteurs optent pour ces disques pour économiser de l'argent, mais se font ensuite sévèrement réprimander par leur patron. Les disques d'extension présentent un défaut critique : l'écriture en boucle.

1st 4Gb : normal writes, files open.
4Gb or more : “Write successful” is displayed and the datd is written to disk – but since no physical space is left, the new data overwrites the old, or just disappears.
Your customer gets the USB stick, copies all their photos and contracts, and opens it up when they get home. And the filenames are all there, but the contents of the files is gibberish or fails to open, all the data is completely out of action.

3. Comment tester la capacité réelle à l'aide de H2testw ?

When faced with this situation, don’t take the vendor’s word for it, and don’t trust what your computer tells you about its properties. The truth will become apparent with just one free piece of software: H2testw. It’s the world standard for determining true capacity in the industry.

Step-By-Step process (Mona’s Step-By-Step Walkthrough):

Download: If that wasn’t obvious enough, just Google search “H2testw download”. It’s free and requires no installation!
Download and unzip/program files: Go to H2testw’s official site http://h2testw.de and download the latest version evidenced at the top of the page. You should have a file named “h2testw_1.4.zip”. First, unzip the file and read through the instructions.
Setup: Insert your USB drive, open H2testw, select English (English interface), and select your USB drive under Target. Test: Select “Write + Verify”. Fills the drive with data and then reads it back to see if it actually is that full.

Voir les résultats (La vérité révélée) :
Tout en vert (Test passed without errors): Congratulations! This is truly a real full-speed storage device.
Turns Red (Data Lost / Corrupted):
ALERT! This is an over-provisioned storage device.
The red bar shows: Actual storage capacity is only X GB, and the other is fake.
The H2testw program is free software that requires no installation and is used for storage media tests: checks for actual capacity of USB drives/SD cards; analyzes bad sectors; analyzes read and write transfer rates.

4. Engagement du fabricant professionnel de clés USB YOUSAN : Nous vendons de la réputation, pas des déchets !

In Shenzhen’s electronics wholesale markets, overcapacity drives can double profits, but YOUSAN usb flash drive steadfastly refuses to manufacture them.
Every chip we use is Grade A genuine full-capacity, such as from Samsung/SK Hynix/Micron, etc. Before shipment, 100% of our QC assembly line conducts H2testw verification. We do not have to “steal capacity” in order to make money, which means we want to see your repeat orders next year!

Les conseils de Mona:
Quel que soit le fournisseur auprès duquel vous achetez des clés USB, envoyez-lui ce message avant de passer commande :
"Acceptation sur la base des résultats du test H2. En cas d'échec (barre rouge), je renverrai toutes les unités et refuserai le paiement."
S'ils répondent de manière évasive, cela signifie qu'ils ont quelque chose à cacher et qu'ils n'oseront pas prendre votre commande. S'il s'agit d'une usine honnête comme YOUSAN, elle vous applaudira.