Last year we saw Micron toy with the idea of dynamically flipping flash memory dies between SLC and MLC modes. Ok paper, it sounded like a great idea – get the speed of SLC flash while the SSD is up to 50% full, then start shifting dies over to MLC mode to get the higher capacity. This tech did not exist until the ability to flip dies between modes existed, which was not until shortly before the M600 SSDs were introduced. Realize this is different than other types of mixed mode flash, like that on the Samsung 'EVO' models, which have a small SLC segment present on each TLC die. That static partitioning kept those types of solutions more consistent in performance than the M600 was when we first evaluated its performance.
What if we borrowed the idea of keeping the flash mode static, but just keeping to the faster mode? Transcend has announced it will be doing just that in the coming year. These will be SSDs equipped with MLC flash, but that flash will be configured to operate in SLC mode full time. This will enable ~4x write speeds and higher endurance ~30,000 write cycles compared to ~5-10k P/E cycle figures of the same flash operating in MLC mode. This performance and endurance boost comes at a cost, as these SSDs will consume twice the flash memory for the equivalent MLC model capacity. We predict this type of substitution for standard SLC flash will be a continuing trend since SLC flash production volume is insignificant compared to MLC. This trick gets you most of the way to SLC performance and endurance for (in the current market) less cost/GB of a straight SLC SSD.
Upcoming Transcend models to include SuperMLC technology:
- SSD510K – 2.5”
- MSA510 – mSATA
- HSD510 – half slim
- MTS460 & MTS860 – M.2