More layers, lower costs
Late last year new developments emerged. First, Samsung released the SM961 series for OEMs based on the new Polaris controller and the new 48-layer 3D NAND flash memory. Soon it turned out that the SM961 suffered from heat problems: the SSD became too hot, because the throttling-mechanism did not work properly. This sometimes resulted in the crashing of the system. Samsung later offered a solution, but considering the OEM nature of the SM961, this solution was only supplied to OEM-partners - people that bought the product themselves still had the same unresolved issue.
Shortly after that, the 960 Pro - that did not have this problem - was released. Both the controller and the flash memory were identical to that of the SM961, but as these were retail-versions, consumers that purchased this model were supported by Samsung directly. With the 960 Pro we also saw the introduction of the first 2 TB PCI-Express SSD, quite a big step up from the 512GB that was the maximum a few months earlier.
For less demanding users, Samsung also released the 960 Evo. The main difference between the Evo and the Pro is that the Evo uses TLC flash memory instead of MLC. This results in slightly lower transfer speeds, especially the write speed of the models with a lower capacity - with the 250GB model this is only 300 MB/sec. However, the 960 Evo remains a big step up from the 850 Evo - on average it is even faster than the 950 Pro. While the 960 Evo could theoretically have more storage capacity because of the TLC-memory, Samsung limits this series to 1 TB.
At the moment Samsung is working on 64-layer 3D NAND memory, which increases the capacities even further. The TLC-dies will be able to store 512 Gbit worth of data, compared with the 256 Gbit that they are able to store at the moment - because the TLC will also be used for the extra capacity and not only for cost reduction as with the 960 Evo.
Last but not least, the odd one out in this test: the Intel 600p and 6000p SSDs. Normally Intel is known for expensive products, but this is absolutely not the case here. By using flash memory that is not exactly fast, these models are a lot cheaper than the other products in the test, but also end up a lot lower in terms of performance level. In fact, the specified speeds are a lot closer to SATA600 SSDs than the average PCI-Express SSD. Nearly immediately after the release of the 600p and 6000p Intel stated that they are working on a successor.
In the mid to long term this is a very promising market segment, because the SATA600-bottleneck is evaded without resulting in a price that is a lot higher. Even the cheaper flash chips are slightly faster in comparison, which means that you receive a 'free' performance gain by using the new interface.