Samsung is first to market with the 990 EVO, which appears to be the inexpensive PCIe 5.0 SSD we have all been waiting for. However, in our tests, the drive performed slower and less consistently when only two PCIe 5.0 lanes were available. Even for PCIe 4.0, it is not very fast and is expensive.
Samsung 990 EVO SSD
Samsung 990 EVO’s features
The 990 EVO is a 2280 form factor (22mm wide, 80mm long) NVMe SSD that uses stacked, 133-layer TLC NAND and an in-house Samsung controller, according to the manufacturer.
It may operate as either a four-lane (x4) PCIe 4.0 (or prior versions at lesser rates) or a two-lane (x2) PCIe 5.0 M.2 SSD, with the same theoretical bandwidth. With the correct BIOS, it could preserve a couple of valuable PCIe 5.0 lanes in that mode. Samsung deserves credit for their innovative efforts.
The Host Memory Buffer (HMB) serves as the primary cache, eliminating the need for DRAM on board. Recent vintage HMBs have proven to be equivalent or better than DRAM-enabled PCIe 4.0 SSDs in sustained transfers, and nearly as fast overall as DRAM-enabled PCIe 5.0 designs.
It is worth noting that this is the first time we have seen or evaluated an HMB/PCIe 5.0 SSD.
The Samsung 990 EVO has a five-year warranty or 600TBW (terabytes that can be written) for every 1TB of capacity. The warranty is standard, as is the TBW rating. Although not quite comparable to Seagate, these drives are far superior to QLC NAND drives.
Samsung 990 EVO costs
SAMSUNG 990 EVO SSD – 50%discount
READ/WRITE SPEEDS UP TO 5,000/4,200 MB/s: Load games and save files in a flash. Bring power to your productivity with read and write speeds of up to 5,000/4,200 MB/s.* The 990 EVO provides continuous speed to keep you going.
The Samsung 990 EVO will be available in 1TB and 2TB variants for $125 and $210, respectively. That is the MSRP, which is approximately double the price of a low-cost HMB PCIe 4.0 NVMe SSD.
Samsung’s high pricing is understandable given the brand’s cachet and repute. However, while the 990 EVO supports PCIe 5.0, it is no quicker than the usual PCIe 4.0. As you will see below.
Samsung 990 EVO performance
The 2TB 990 EVO that Samsung supplied us was a pretty unimpressive performer. It is by far the slowest PCIe 5.0 SSD we have tested, and whether PCIe 5.0 or 4.0 was used, it only met the PCIe 4.0 benchmark.
But the main issue was that the PCIe 5.0 CrystalDiskMark 8 figures varied greatly across runs, ranging from 3GBps to 5GBps reading. Normal fluctuation is limited to a few hundred megabits per second.
Due to the discrepancy, we throttled our testbed’s PCIe M.2 slots to 4.0 and retested. When using the 990 EVO via PCIe 4.0, the CrystalDiskMark 8 and AS SSD 2.0 (not shown) results ranged from somewhat quicker to significantly faster, and were completely constant between tests — around 5GBps reading and 4GBps writing sequentially in CrystalDiskMark. Most likely, HMB, as implemented on the 990 EVO, prefers more pipes, even if they are only half as fast.
The competing Teamgroup MP44 and WD SN770 are both PCIe 4.0 HMB designs. The Crucial T700 is included to demonstrate what is possible with PCIe 5.0 (and DRAM).
The 990 EVO’s 4K performance (see below) in CrystalDiskMark 8 was significantly more competitive.
Our real-world sequential 48GB transfer tests were gentler on the 990 EVO than CrystalDiskMark 8 — at least while secondary cache (TLC written as SLC) remained intact. In fact, it outperformed the overall winner, the Crucial T700, which had a surprisingly difficult time reading smaller files and folders despite performing admirably in all other areas.
The Samsung 990 EVO writes to secondary cache at over 3GBps, although this lowers to roughly 1.15GBps when writing straight to the TLC NAND. That is actually not that awful considering that hard drives only handle 250MBps and SATA SSDs max out at 525MBps. It is not ideal, but it is not as bad for NVMe as the 150MBps you will experience when some QLC drives run out of secondary cache.
It should be noted that the PCIe 5.0 difficulties may only affect our testbed and not other machines. The complete testbed configuration may be obtained at the conclusion of this post. The motherboard is the Asus ROG STRIX Z790-i. We paid pay for it, therefore we do not usually give the company free publicity, but in this situation, the make and model may be relevant.
SAMSUNG 990 EVO SSD SAMSUNG 990 EVO SSD – 50%discount
READ/WRITE SPEEDS UP TO 5,000/4,200 MB/s: Load games and save files in a flash. Bring power to your productivity with read and write speeds of up to 5,000/4,200 MB/s.* The 990 EVO provides continuous speed to keep you going.
Should you buy it?
With four PCIe 4.0 lanes instead of two PCIe 5.0 lanes, the 990 EVO performed faster and more consistently. We are not sure why; nevertheless, forget about the PCIe 5.0, as innovative as it is, and consider it a slightly more expensive, average-performing PCIe 4.0 SSD, then make your pick.
