For the controller, Intel is again using a model from Silicon Motion: The SM2263EN uses four NAND channels and can use a DRAM cache, in contrast to its slower sister model SM2263XT. For random-access the 660p reading and writing should reach up to 220,000 IOPS, which means a significant increase over the 600p.
For sequential transfers, the 660p should reach up to 1,800 MB / s for reading and writing (in the SLC cache), the 600p writes at a maximum of 560 MB / s significantly slower. However, the 1,800 MB / s is only for writing in the SLC cache. If this is exhausted, writes the 660p only about 100 MB / s and is thus even slower than the 600p – an Achilles heel of the QLC-NAND. The SLC cache can compensate for this as long as the data to be transferred fits into it.
Fixed and dynamic SLC cache
Intel has switched to a dynamic SLC cache on the 660p: a small static part of 6 to 24 GB is always available. If enough QLC flash is still available, the size can grow up to 76 to 280 GB. A graphic illustrates the dynamic size of the SLC cache depending on the amount of space used. Intel claims that 50 percent of PC users save only 235 GB or less of data. The fact that this is true for owners of an SSD with 1 TB and larger, the editorial holds but very unlikely. Should the SSD be filled with data for more than 75 percent of its storage capacity, the size of the then static SLC cache might not always be sufficient.
An example: If the 1 TB model is 80 percent full, according to Intel’s graphics, the SLC cache should only hold 12 GB. After all, the predecessor 600p always offers 32 GB fixed SLC cache for the 1 TB model. For everyday life, this is still more than enough, but larger transfers then run at a snail’s pace on HDD speed, as PC World criticized in the test.
Despite this weakness, many testers in the US agree that the Intel SSD 660p offers good value for money. In other disciplines, the results are sometimes at a high level. Price recommendations of $ 99 for 512 GB and $ 199 for 1 TB are a competitive price for an NVMe SSD, and at around 20 US cents per GB, only the cheapest SATA SSDs are cheaper (and slower). Intel has not yet revealed the price for the following 2 TB model.
Durability: 5 year warranty meet low TBW
Concerns about the potentially lower durability of QLC Flash are dispelled by Intel’s five-year warranty. About 1,500 write cycles are said to be the QLC-NAND by Intel and Micron , which is also sufficient for normal users . However, the minimum guaranteed write amount specified in Drive Writes Per Day (DWPD) or Terabytes Written (TBW) is lower than many TLC-based models, Tom’s Hardware noted.