Posts by: CustomUSB

NAND Flash Chip Types – SLC, MLC, TLC

USB drives are available in three types of flash, SLC (single-level cell), MLC (multi-level cell) and TLC (triple-level cell). Each one has its distinct uses.

  • SLC (Single-Level Cell)
  1. High performance / faster write speeds
  2. Long-term reliability – 100,000 program/erase cycles per cell
  3. Has two states: programmed or erased
  4. Used for embedded and industrial applications
  5. Higher cost
  • MLC (Multi-Level Cell)
  1. Lower endurance than SLC
  2. 10,000 program/erase cycles per cell
  3. Has four states: fully programmed, partially programmed, partially erased and fully erased
  4. Used for consumer applications
  5. Lower cost
  • TLC (Triple-Level Cell)
  1. Lower endurance and performance than SLC and MLC
  2. 5,000 program/erase cycles per cell
  3. Has eight states and is thus slower in operation
  4. Used for low-end applications that require cost efficiency
  5. Most cost efficient

Each of these has its place in the market. We can help you determine which one to use based on your requirements. Email if you have any questions or comments.

USB Controller and NAND Flash Read Write Speed Study

After being in the business for more than a decade, we have finally decided to publish a Flash study. This will be an ongoing project so keep checking this page for updated reports. If you have anything to add or have any questions, put them in the comments or email

Since we kick-startedĀ  the customized USB industry eight years ago, a lot has changed. Pricing has significantly come down, market demand has increased and technology has improved. We now stock more drives than we sold when we first started. Throughout the years, we have seen many different types of drives come across our desk and have always tried to use the most reliable components. This is what we knew then. This is what we know now:

  1. Most NAND Flash is made by Samsung, Toshiba, Micron, Hynix, and Intel.
  2. The smallest capacity currently produced by the NAND Flash Manufacturers (listed above) is 8GB. All smaller capacities that you see on the market are made using downgraded Flash.
  3. Downgraded Flash is derived from higher capacity chips that have failed sectors. The bad sectors are partitioned off and the chip is used as the next smallest capacity. (e.g. an 8GB chip with failed sectors can be used as a 4GB, unless the failed sectors give the chip less usable space than 4GB. In that case, the chip would be used as 2GB or lower.)
  4. USB Controller is responsible for functionality of the USB drive. The combination of Controller chip and Flash chip (as well as other components) determine the quality of the USB drive.
  5. In the OEM market, the most popular Controllers are Alcor Micro, SMI (Silicon Motion), and Chipsbank.

For this study, we have tested several brand name USB drives from our partners as well as OEM drives that we either assemble ourselves or source from China. We use (or have used) all of these components on a customers’ budget and technical requirements.

We used CrystalDiskMark to measure sequential read/write speed using 50MB and 1GB (1000MB) test sizes. We also used Check Flash to test the drives for errors.


  1. SanDisk Flash and Controller
  2. 16GB USB 2.0 tested > 14.9GB of usable memory
  3. Read Speed: 21.66MB/s, Write Speed: 3.966MB


  1. Toshiba Flash and TC58NC226166F Controller
  2. 8GB USB 2.0 tested > 7.24GB of usable memory
  3. Read Speed: 19.13MB/s, Write Speed: 9.473MB/s
  4. Controller VID 0930 and PID 6545


  1. Unidentified Flash, ITE IT1167BE Controller
  2. 4GB USB 2.0 tested > 3.75GB of usable memory
  3. Read Speed: 21.90MB/s, Write Speed: 7.046MB/s
  4. Controller VID 048D and PID 1168

SuperTalent USB 3.0

  1. Micron Flash, Innostor IS902 Controller
  2. 8GB USB 3.0 tested > 37.17GB of usable memory
  3. Read Speed on USB 2.0 Port: 36.86MB/s, Write Speed on USB 2.0 Port: 13.24MB/s
  4. Controller VID 1B8F and PID 0902

OEM Alcor AU6989

  1. Unidentified Flash, Alcor AU6989 Controller
  2. 8GB USB 2.0 tested > 7.48GB of usable memory
  3. Read Speed: 15.35MB/s, Write Speed: 3.568MB/s
  4. Controller VID 058F and PID 6387

OEM Chipsbank CBM2096

  1. Unidentified Flash, Chipsbank CBM2096 Controller
  2. 2GB USB 2.0 tested > 1.87GB of usable memory
  3. Read Speed: 13.96MB/s, Write Speed: 5.098MB/s
  4. Controller VID 1E3D and PID 2096

OEM Unidentified “Blob”

  1. Unidentified Flash, Unidentified Controller
  2. 2GB USB 2.0 tested > 1.86GB of usable memory
  3. Read Speed: 17.20MB/s, Write Speed: 6.219MB/s
  4. Controller VID 058F and PID 6387 (according to research this USB drive uses a Chipsbank CBM2096 controller)

As we said earlier, this will be an ongoing project so keep checking this page for updated reports. If you have anything to add or have any questions, put them in the comments or email

King Fahd University Water Tower USB Drives

King Fahd University of Petroleum and Minerals (KFUPM) is celebrating its 50th anniversary this year. As part of the celebration, students and faculty will receive custom made gold plated water tower USB drives. The water tower has been a distinctive KFUPM landmark, kind of like the UC Riverside flash drives we made a while back.

iStorage Encrypted PIN USB Flash Drives

We recently added a super-encrypted uber-secure USB drive to our web store. The iStorage USB drive is the world’s most secure easy to use flash drive. It uses PIN code access with military grade AES 256-bit hardware encryption. It does not require any software or drivers to be installed and is compatible with PC, MAC, Linux.

Perfect for travel
Rugged water resistant design
Secured with 7-15 digit PIN
Automatically locks when unplugged
Drag-and-drop real-time encryption
Laser engraved with your name or website

Bronze Wallet Card USB Drives for Nike

The Wallet Card Pro generally comes in silver and black finishes only. But when we heard about Nike’s requirements, we couldn’t say no. So for this limited edition run we anodized the casing in bronze and pad printed the logo in black on the top side. This dedication to our craft keeps clients like this coming back year after year.

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