Standard Technology – SLC versus MLC

Understanding NAND Flash

NAND Flash has earned the reputation of being the top choice in today's media-rich mobile consumer electronics.

Two types of NAND flash

Two types of NAND Flash are available in USB flash drives - SLC and MLC.

What is SLC?

Single-Level Cell (SLC) flash outperforms Multi-Level Cell (MLC) flash. Buffalo's high-performance USB Flash products, as well as PDAs and digital video players, use this type of flash technology.

What is MLC?

Multi-Level Cell (MLC) flash has low-cost benefits, but performs at slower speeds.

Advantages of SLC over MLC

Three main advantages for using NAS:

• Faster write speed
  
  SLC flash accesses and writes to the flash faster by using "simpler" control logic with 1 bit versus the 2 bits used by MLC flash.
• Longer lifespan
  
  The program operations in SLC chips last 100,000 cycles, ten times longer than MLC.
• Lower aggregate cost
  
  At a first glance, SLC flash appears to be more expensive than MLC. However, taking into consideration the higher reliability and lifespan of SLC, the aggregate cost is for SLC is lower.

Table 1 Comparison between SLC and MLC

Item SLC MLC Voltage 3.3V / 1.8V 3.3V Technology / Chip Size 0.12um 0.16um Page Size / Block Size 2KB / 128KB 512KB / 32KB or 2KB / 256KB Access Time (Max.) 25us 70us Page Program Time (Typ.) 250us 1.2ms Partial Program Yes No Endurance 100K 10K Write Data Rate 8MB/s+ 1.5MB/s

Buffalo Flash products powered by SLC technology

Buffalo uses the latest SLC technology flash combined with Buffalo's 4x memory interleaving chipsets (accessing 4 memory banks simultaneously, rather than sequentially). This ensures Buffalo offers the highest quality and best-performance flash in the market.

USB Flash Drive 256 MB Type-S RUF2-S256-WH USB Flash Drive 512 MB Type-S RUF2-S512-WH USB Flash Drive 1GB Type-S RUF2-S1G-WH USB Flash Drive 2GB Type-S RUF2-S2G-WH