\"The market has decided\" is a phrase often heard from skeptics who believe that free competition without regulation inevitably leads to quality deterioration due to manufacturers' desire to reduce production costs indefinitely.While this may be the case, the market has taken a turn for the worse in the low-cost PCIe 4.0 SSD segment.Indeed, leading manufacturers have almost completely abandoned the use of QLC-memory in such drives and now cheapen them not at the expense of slow flash memory with low life expectancy, and by using four-channel controllers and the introduction of technology HMB instead of adding a buffer SDRAM-memory.Initially, this design does not seem a good option - until recently, bufferless NVMe-drives do not look particularly attractive, offering a deliberately lower performance against their full counterparts.The only relatively bright spot in this segment was the Samsung 980, but even that could not compete with midrange drives even from second- or third-tier companies, let alone more pedigree products.But progress does not stand still, and very recently the market competition gave birth to the Innogrit IG5220 bufferless platform, a high class budget solution.The first Patriot P400 SSD in our lab was a real sensation: as it turned out, bufferless SSDs are no longer a verdict, and in real-world workloads they are quite capable of offering near-flagship performance. Even better, the Patriot P400 has stirred up other manufacturers as well, who also began to produce similar or even better in consumer characteristics solutions.So, quite recently Western Digital has released a novelty that is no less attractive.Despite the fact that at the end of last year it already released bufferless PCI 4.0-drive WD Black SN750 SE based on public platform Phison E19T, now it was replaced by a new model, strengthened on all fronts - WD Black SN770.And this is a direct result of the market mechanisms.WD Black SN750 SE, obviously, could not compete adequately with solutions like Patriot P400, and Western Digital had to urgently restructure the lineup.And this time the company decided not to step on the same rake a second time and instead of choosing another publicly available platform for the inexpensive PCIe 4.0 SSD made its own, which should be even better.That's how the new hero, the WD Black SN770 appeared, which, although inspired by the Innogrit IG5220 platform, is made from start to finish by SanDisk's internal engineering team.Judging by the specs, the WD Black SN770 offers about a half as much performance as the Black SN750 SE and gets into the same league as the Crucial P5 Plus, even though we are talking about a simple bufferless model.That said, the Black SN770's recommended price is on par with the Black SN750 SE and almost identical to the Samsung 980's recommended price, which is causing a lot of interest in the novelty.And although Western Digital drives are no longer supplied to Russia through the official channel, there is hope that the Black SN770 will still get to domestic retailers under the parallel import scheme.To prepare ourselves for this moment, we have carried out comprehensive testing of this SSD.⇡#Appearance and internal designWD Black SN770 is made as a single-sided M.2 2280-board with black textolite and without any pre-installed cooling means.You could say that it looks like a typical budget SSD, but there is one peculiarity - all its stuffing is tightly packed into just two chips. One chip is a proprietary SanDisk controller labeled 20-82-10081-A1.Western Digital does not disclose details of its developments, but we know that this chip is built on the same functional blocks as the controller 20-82-10034-A1, which is used in the flagship WD Black SN850.But in this case it is considerably simplified: DRAM interface is removed from it, instead of which the support of HMB technology is added, as well as the number of flash-memory channels is reduced to four.However, there is good news.First of all, the WD Black SN770 controller still has full support for four PCIe 4.0 lanes.Secondly, it is compatible with the modern and fast 112-layer BiCS5 memory with an interface frequency of 1.2 GHz, which Western Digital has been producing since the beginning of last year. In fact, the second chip on the WD Black SN770 carries SanDisk's BiCS5 memory chips.In this case it is 512 Gbit TLC 3D NAND devices in the amount corresponding to the capacity of the drive.For the purposes of this review we are considering a terabyte, and in it the flash memory array is assembled from 16 crystals
