Is a MLC still slower and less reliable than a SLC SSD

laptopssd

Most laptop vendors seem to supply relatively cheap MLC drives with their pre-built configurations.

I know that the traditional drill is that a SLC is fast and reliable while a MLC is slower and less reliable; but I've heard that in a last years lots of elaborate algorithms and workarounds made MLC almost as good as SLC. Can anyone show me some definitive modern benchmarks that either prove or dismiss this fact?

Best Answer

All recent consumer drives use MLC flash. Even some enterprise-focused SSDs also use MLC, although with Intel's MLC-HET:

Similar to frequency binning CPUs, the highest quality NAND with the tightest margins gets binned into MLC-HET while everything else is shipped as standard MLC. And just like with frequency binning, there's a good chance you'll get standard MLC that will last a lot longer than it's supposed to. In fact, I've often heard from manufacturers that hitting up to 30K p/e cycles on standard MLC NAND isn't unrealistic. With its MLC-HET Intel also more frequently/thoroughly refreshes idle NAND cells to ensure data integrity over periods of extended use.

So the extra P/E cycles - and therefore increased longevity of the flash memory - come from picking the highest quality NAND chips, as well as adding a significant spare area of 41%.

As for performance, the MLC Intel 710 is generally slightly slower than its older SLC cousin, the X25-E (but the 710 is far cheaper to compensate). Regardless, SandForce MLC drives usually dominate SSD benchmarks due to real-time compression in the controller, rather than depending upon the intrinsic speed of SLC.

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