The primary points of comparison for this review are other SATA SSDs using 3D NAND. This extra overprovisioning can help mitigate some of the performance penalties of using a DRAMless controller, but the bigger benefit is probably that it helps keep the write endurance ratings up in spite of the higher write amplification factor that DRAMless drives are typically vulnerable to.
HP SSD S700 SOFTWARE PRO
The S700 has the same amount of flash memory as the S700 Pro but offers lower usable capacities. These discrepancies probably reflect the supply constraints in the NAND and DRAM markets and these minor details may change over the course of the SSDs' production run.
Likewise, the DRAM parts are different across the S700 Pro lineup: our 128GB and 256GB samples are both equipped with 256MB of DDR3-1866 rated for 1.5V operation, while the 512GB sample has 512MB of DDR3-1600 rated for 1.35V. Interestingly, the dual-die packages on our 256GB S700 Pro sample carry a higher speed rating than the dual-die packages on our 512GB S700 Pro sample, but this is unlikely to affect performance since the single-die packages on both carry a lower speed rating than either type of dual-die package.
Intel and Micron have addressed this awkwardness with their second generation of 3D NAND by designing it with TLC in mind as the primary use case, leading them to manufacture 256Gb and 512Gb TLC dies. These unbalanced configurations are a result of the drives trying to offer traditional capacities while using a TLC die whose capacity is not a power of two. The larger models can use all four channels but don't have the same amount of flash on each each of the four channels. Since the SM2258 controller and its DRAMless SM2258XT sibling have a four-channel NAND flash interface, both the S700 120GB and the S700 Pro 128GB are operating with only three out of four channels active. The higher capacities of the S700 instead use non-standard triple die packages that-combined with the lack of external DRAM-allows for a much smaller PCB.
The larger capacities of the S700 Pro use a mix of single-die packages and dual-die packages (two of each on the 256GB, and four of each on the 512GB). The 120GB S700 and the 128GB S700 Pro are each equipped with three NAND packages containing a single 384Gb (48GB) Micron 32-layer 3D TLC die. Thermal pads are included on top of the controllers and on the back side of the PCB near the controllers, but there are no pads on the NAND or DRAM. Neither circuit board has space allocated for power loss protection capacitors, indicating that HP doesn't plan to re-use these designs for any enterprise products. The controllers are branded with the HP logo, but the printing on the PCBs gives away the Silicon Motion models inside. The S700's PCB is half the size of the S700 Pro's PCB, due to the latter's use of external DRAM, the larger controller package necessary to accommodate the DRAM interface, and the presence of twice as many pads for NAND packages to make the 1TB S700 Pro possible. Internally, the color scheme continues with black PCBs, and the differences between the S700 and the Pro become clear. Earlier this year we previewed Maxiotek's MK8115 DRAMless SSD controller with both 3D MLC and 3D TLC, and the latter configuration has since come to market as ADATA's Ultimate SU700.Įxternally, the HP S700 and S700 Pro share the same minimalist case design with white labeling on matte black aluminum. The S700 instead uses the Silicon Motion SM2258XT DRAMless controller, and is the first retail DRAMless SSD we've tested in quite a while. The S700 Pro's closest relatives in the market are drives like the ADATA Ultimate SU800 that use the same 3D TLC and Silicon Motion's SM2258 controller. The S700 and S700 Pro both compete in the low-end SATA SSD market segment. The HP S700 and S700 Pro SSDs use Micron 3D TLC NAND and Silicon Motion controllers, but have undergone tuning and significant QA from HP in an effort to give them an edge over earlier drives from other vendors that are using the same basic formula.
HP SSD S700 SOFTWARE PC
HP is not a well-known name in the retail SSD market, but as a major PC OEM it's not too surprising to see them producing their own SSD models based on third-party controller solutions.
0 kommentar(er)
