There are two main reasons why QLC flash memory is not liked by everyone. One is poor reliability, and the other is poor writing performance. These are all determined by the characteristics of QLC flash memory. After all, 4bit data must be controlled in the cell unit, and programming and writing It is much more complicated than other flash memory when entering, so the error rate is high and the speed is slow.
We have also seen the hard disk performance of QLC flash memory, although the write speed given by the manufacturer exceeds 1GB/s or even 2GB/s,However, it is all improved by technologies such as SLC cache, full disk cache, and DRAM cache. The original write speed of QLC is very low, and the performance outside the cache is worse than that of HDD hard disks. There are almost no ones exceeding 100MB/s.
Western Digital and Kioxia’s current main flash memory, BiCS5, has no QLC flash memory type. The next generation of BiCS6 flash memory will re-launch QLC flash memory with a lot of performance optimization. Not only the core area is lower than other manufacturers, but also the programming speed (ie write speed) increased to 60MB/s.
What is this concept? Although it doesn’t look high,However, the QLC programming speed in the previous generation BiCS4 flash memory is only 9.7MB/s. The fastest programming speed in the current QLC flash memory is Intel’s 144-layer QLC flash memory, with a speed of 40MB/s, and most of other manufacturers are within 30MB/s.
To put it simply, the QLC speed in the BiCS6 flash memory of Western Digital and Kioxia is 5 times faster than before, and the performance is also improved by 50% compared to the fastest QLC of a friend, which is enough to greatly improve the QLC flash memory.SSDThe writing performance of the hard disk depends on the finished product.
