Thoughts on SAMSUNG 990 Pro Leave a comment

The Samsung 990 Pro is the eagerly awaited replacement for the well-liked 980 Pro. It is expected to surpass both the SK hynix Platinum P41 and the Western Digital (WD) SN850X to become the extremely fast drive we’ve tested. The 990 Pro will release a 4TB model in addition to the 1 and 2TB models that are currently available for $169 and $289, respectively. The Samsung 990 Pro, which is available without a heatsink or with one that is coloured RGB, uses the company’s new Pascal controller and V7 TLC NAND storage, which together should make the device faster and more effective.

The other Samsung extras, such as software support for the new Magician application and the ability for encryption, are available on the 990 Pro. The drive is made to fit in a variety of gadgets, including desktop computers, laptops, and the PlayStation 5 (PS5) console. The 990 Pro is intended to compete with the greatest SSDs in terms of performance as Samsung’s new top-of-the-line consumer PCIe 4 SSD, and in our tests, it succeeds.

At launch, the Samsung 990 Pro is available in 1TB and 2TB capacities. The 4TB variant won’t launch until 2023, but it will be good to see Samsung provide a greater capacity choice. The 990 Pro boasts sequential read and write speeds of up to 7450/6900 MBps and read and write IOPS of up to 1.4 million/1.5 million. This is more than competitive, outperforming the 980 Pro from the previous generation in every way while also indicating performance gains over the SK Hynix Platinum P41 and WD SN850X.

The Samsung 990 Pro delivers 600TB of warrantied writes per TB of capacity and does support TCG Opal encryption, a feature that is not supported by many consumer SSDs. The JEDEC JESD218 standard, which is mainly irrelevant, is followed for the endurance rating. Although the TBW ratings are average in any event, they ought to be adequate for the drive’s intended application.

Following the WD SN850X’s lead, Samsung is providing a variation at each capacity with a heatsink and RGB. Contrary to the SN850X, it appears that the 4TB variant will also include this feature. The lack of a cooling option makes the Platinum P41 possibly a little less appealing. The heatsink of the Samsung 990 Pro complies with PCI-SIG D8, which implies that it is less than 8.8mm tall and will fit into a range of devices, including the PS5.

Prices for the Samsung 990 Pro at launch range from $169.99 for 1TB to $289.99 for 2TB. Each price is increased by $20 by the RGB and heatsink, matching the SN850X’s premium. One issue we had with the SN850X was that it cost too much at launch, although that has significantly decreased since then. Samsung’s T7 Shield likewise had a large MSRP at launch, but the drive was never actually sold at that price. Given the current real-world pricing of its main rivals, we therefore anticipate the 990 Pro to be lowered.

Prior to the 990 Pro’s launch, Samsung published Magician storage software version 7.2 on October 4. The heatsink variants of the drive can now be controlled with RGB thanks to this programme. Additionally, it offers diagnostics, firmware updates, and driver updates in addition to enabling data movement. There are more features as well, like a PSID reversal that can secure wipe data and unlock an encrypted disc. The industry norm for SSD software is generally Samsung’s.

Additionally, this software offers a Performance Optimization panel with a Full Performance Mode option. This brings to mind the old Game Mode on WD, which in essence disabled lower power states. We benchmarked in both the “Full Power Mode” on and off during our tests.

The 990 Pro has ordinary aesthetics and a sticker on the front and back that provides drive information in the bare minimum. Reduced load temperatures are aided by the heat spreader rear label. Two NAND packages, a DRAM package, and the controller are all located beneath the top label. The 990 Pro incorporates Samsung’s Dynamic Thermal Guard (DTG) in addition to nickel plating the controller to increase heat dissipation and increase thermal stability. This is similar to the adaptive temperature management feature on the SN850X, which we have previously seen earlier in the 980 Pro. Despite being nothing new, this technology might ease the burden of gaming.

In the Samsung 990 Pro, the Pascal controller has taken the position of the Elpis controller from the Samsung 980 Pro. Samsung’s 8nm manufacturing node is used to create the Pascal, which continues to be based on ARM. Although there don’t appear to be many changes between the controllers at first glance, the Pascal has significantly higher performance demands. Samsung claims that this is because of a simplified NAND data flow with “hardware automation technology” that is activated and has a “cache algorithm” that allows for faster processing. Samsung responded that this architecture was created to offer more effective read caching and low-power mode coverage when I questioned them about the changes.

The controller uses volatile memory, such as SRAM, to cache mapping information and buffer data before committing it to the non-volatile NAND flash, so algorithm optimization can boost overall speed. Such improvements frequently have a greater positive impact on write speed, but DirectStorage adjustments may also be important. Some manufacturers, like Solidigm, have also chosen to implement a type of caching that uses an exclusive NVMe driver to store particular data in the cache. When that happens, metadata, or knowledge about the type of data and how it is used, can improve performance through clever caching. The term “read caching” was not defined by Samsung, however it is usual practise to retain some hot data in pSLC to facilitate future reads.

The least recently accessed data would be removed from a full cache first according to the least recently used (LRU) cache algorithm. If an algorithm does not include spatial proximity, or the knowledge of surrounding and adjacent memory regions, it is restricted. Performance bottlenecks can be caused by the FTL overhead that will inevitably rise with more complicated algorithms. By offloading or automating some of this work, certain controller upgrades can raise the maximum IOPS. While the full benefits are unlikely to be felt on a consumer device, this can also typically result in lower latency.

Although Samsung has improved the controller, other parts are more recognisable. Samsung’s LPDDR4 DRAM, which is used in several of its SSD products, serves as the memory. In comparison to conventional DDR, it provides some power savings. This module’s 2GB capacity perfectly complements the 2TB of flash memory. The 1TB model is anticipated to include 1GB. Samsung also uses common power components. In compared to the 980 Pro, we would anticipate the new flash and controller enhancements to be the source of the projected power reductions.

The K9DVGY8JRD-DCK0 label on the flash packages indicates that the memory is Samsung’s 176-layer TLC NAND. Although the future 4TB may need 1Tb “X” dies, the 2TB SKU indicates that this flash has 512Gb dies by using the letter “V”. According to Samsung’s V-NAND nomenclature, which was extensively discussed at ISSCC 2021, this is V7. The production of higher-layer flash has typically been put on hold by current trends in the flash market, despite Samsung exhibiting its 8th generation TLC at ISSCC this year. In any case, this flash, a direct upgrade to the V6 128-layer TLC seen in the 980 Pro, has never before been seen.

The most major changes made by Samsung with this generation of flash were the usage of a four-plane architecture and the implementation of Cell-on-Periphery (COP). More planes equate to more parallelization, which at the very least results in increased bandwidth. COP is comparable to Micron’s CMOS-under-Array (CUA), but Samsung is using it for the first time in this application. Control circuitry must be relocated from the array’s side or periphery in order to accomplish this. By putting peripheral circuitry under the array of data cells, this can significantly increase power efficiency while also reducing die surface area.

Samsung experienced some issues as a result of placing this circuitry beneath the array, but they were able to fix them by employing a creative capacitor design. As a result, less surface area is used while power delivery is improved. When full I/O speeds are not required, Samsung additionally employs a dual-scheme termination approach that allows for better power efficiency. This ought to support Samsung’s assertion that a low-power-aware architecture improves power efficiency.

The utilisation of several NAND array decks with larger flash layer counts, or string-stacking, is only possible with Samsung as a manufacturer. Although it has several drawbacks, this strategy also avoids dealing with merging decks. Since there are so many layers to etch, the aspect ratio increases, which, among other things, can raise the voltage threshold divergence across cells in various levels. It is true that having more layers in a given area reduces the effective cell capacity, which can also affect performance and endurance.

To resolve this problem, Samsung’s approach adds an additional latch, a type of dynamic buffer similar to page buffers. The additional information is used in conjunction with word line and bit forcing approaches to create a refined cell charge, basically adding an extra verify stage to maintain tighter bit values. While it is theoretically conceivable for a manufacturer to reach 800 or more levels by merely adding decks, this method is not without its own difficulties. Instead, Samsung has decided that their 176-layer NAND offers the best possible compromise between performance and battery usage.