Continuing our dive into newcomer Realtek's SSD controller lineup thanks to several ADATA products, we turn to the ADATA XPG SX6000 Pro, an entry-level NVMe SSD.

As mentioned in our previous SSD review, Realtek is a well-known PC components supplier that is relatively new to the SSD controller business. ADATA has provided Realtek with their most significant SSD design wins, starting with the original SX6000 that used Realtek's very first SSD controller, the RTS5760. The SX6000 Pro targets the same entry-level NVMe market segment, but switches to the second-generation RTS5763DL controller. That newer controller brings a desperately-needed process shrink to enable an upgraded PCIe link and much better performance and power efficiency.

As a late entrant to the SSD market, Realtek is focusing primarily on NVMe rather than SATA. Given that they also prefer to be the low-cost, high-volume alternative rather than pursue high-end niches, the RTS5763DL is probably the most important SSD controller in their current lineup. This controller has a four-channel NAND interface, four PCIe lanes and no DRAM controller, so at a high level it is on par with the Silicon Motion SM2263XT and the upcoming Phison E13T.

ADATA has paired the Realtek controller with Micron's 64-layer 512Gbit TLC NAND, organized as four packages with four dies each for our 1TB sample, all on one side of the M.2 card thanks to the small size of the controller and the lack of an extra DRAM package. The use of 512Gb instead of 256Gb dies cuts costs slightly, but is usually avoided on high-end drives because having fewer dies limits the degree of parallelism available to the SSD controller. This isn't a problem for the 1TB SX6000 Pro since the four-channel controller is a bigger limitation. Since the 256GB and 512GB models of the SX6000 Pro don't have severely curtailed performance specs, ADATA may have made the smart choice to use the 256Gb dies on at least the smallest model.

 ADATA XPG SX6000 Pro Specifications
Capacity 256 GB 512 GB 1 TB
Form Factor single-sided M.2 2280 PCIe 3.0 x4
Controller Realtek RTS5763DL
NAND Flash Micron 64L 3D TLC
DRAM None (HMB Supported)
Sequential Read 2100 MB/s 2100 MB/s 2100 MB/s
Sequential Write 1200 MB/s 1500 MB/s 1500 MB/s
Random Read 190k IOPS 250k IOPS 250k IOPS
Random Write 180k IOPS 240k IOPS 240k IOPS
Idle Power 0.14 W
Warranty 5 years
Write Endurance 150 TB
0.3 DWPD
300 TB
0.3 DWPD
600 TB
0.3 DWPD
Current Retail Price $39.99

For SATA SSDs, the lack of a DRAM cache pretty much always condemns a drive to have extreme low-end performance. For NVMe SSD, going DRAMless doesn't carry such a harsh penalty and entry-level NVMe SSDs usually have no trouble offering better real-world performance than mainstream SATA SSDs with DRAM caches. This is often achieved with the help of the NVMe Host Memory Buffer feature that lets the SSD borrow a chunk of the host system's DRAM (64 MB in the case of this drive) to use as a cache for the drive's internal data structures used for managing the flash memory. However, toggling HMB on and off didn't produce a meaningful performance difference for any of our tests on the SX6000 Pro, which leaves us questioning whether ADATA and Realtek enabled the feature just to check a box on the spec sheet. We can't actually directly observe the drive's use of HMB without a PCIe bus analyzer, but regardless of how (or if) the SX6000 Pro is making use of HMB, the lack of a measurable effect means we're only bothering to graph the results from our test runs with HMB on, which is the default for any recent OS.

As usual, ADATA bundles the SX6000 Pro with a thin heatspreader that the user can apply if desired, which we never do for regular reviews. ADATA is also selling the same drive as the XPG GAMMIX S5, which has a slightly fancier heatsink pre-installed.

The Competition

We have tested several other entry-level NVMe SSDs that are in direct competition with the SX6000 Pro. The Mushkin Helix-L uses the Silicon Motion SM2263XT controller, another DRAMless 4-channel design with HMB support. The Intel 660p (and the newer 665p) use the SM2263 with DRAM, and use QLC NAND instead of TLC. The Toshiba (now Kioxia) BG4 doesn't currently have a retail version, but it's a popular OEM SSD that likewise is DRAMless.

Phison's entry-level NVMe solutions are missing from this comparison because their E8T controller is pretty old and unpopular at this point, and drives using the successor E13T and E19T controllers haven't quite hit the market. The recently-released WD Blue SN550 adds the 1TB option that the earlier SN500 lacked. These two drives are particularly interesting because they are DRAMless NVMe SSDs that don't use the Host Memory Buffer feature, but our test results from the 250GB SN500 don't really provide a fair comparison against 1TB drives.

As always, it's important to keep an eye on how entry-level NVMe drives perform relative to the more popular high-end models with 8-channel controllers and full-size DRAM caches, because the cheapest high-end drives are usually priced pretty close to entry-level NVMe SSDs. And lastly, representing the SATA SSD market segment, we include the Crucial MX500 as the mainstream choice, and the ADATA Ultimate SU750 featuring Realtek's DRAMless 2-channel SATA controller.

AnandTech 2018 Consumer SSD Testbed
CPU Intel Xeon E3 1240 v5
Motherboard ASRock Fatal1ty E3V5 Performance Gaming/OC
Chipset Intel C232
Memory 4x 8GB G.SKILL Ripjaws DDR4-2400 CL15
Graphics AMD Radeon HD 5450, 1920x1200@60Hz
Software Windows 10 x64, version 1709
Linux kernel version 4.14, fio version 3.6
Spectre/Meltdown microcode and OS patches current as of May 2018
Cache Size Effects


View All Comments

  • Billy Tallis - Wednesday, December 18, 2019 - link

    My mindset is that your complaint isn't specific to the SX6000P; it's true of the entire category of "low-end NVMe" drives, so I don't want to single out the SX6000P for suffering from the same problem that all of its closest competitors also suffer from. It's halfway-decent at what it's trying to be, but it's trying to compete in a niche that barely exists in the first place.

    At least for the retail SSD market. The most popular retail NVMe SSDs are all high-end drives, so they get economies of scale that the low-end models don't, and that's why E12 and SM2262 drives can be priced so close to low-end NVMe. But in the OEM market, low-end NVMe drives do have a more compelling value proposition, and that's where the controller vendors make the real money.

    That in turn influences what kind of drive designs the SSD vendors have on hand to readily convert into a retail product. The best example of this is the WD Blue SN500/SN550 series, which existed as an OEM product for a year before it came to retail. There's also Toshiba's BG series, which has been through four generations and they only bothered to do a retail release of one of them.
  • Great_Scott - Wednesday, December 18, 2019 - link

    The SSD market is and has been monstrously compressed.

    The difference between performance tiers for SATA is frequently $10/tier. (excepting the occasional Samsung drive.)

    I don't see that anything is substantially different for NVMe. This is a good, maybe great, budget drive. The problem being that you can spend $10 for a far better one.

    At some point in the future where price isn't entirely dictated by Flash BoM this might change, but for now it only makes sense to get the best drive in a category since they all cost about the same.
  • Freeb!rd - Thursday, December 19, 2019 - link

    My thoughts also... I was looking at NVMe Gen4x4 drives at around $200 for 1TB, but then saw the EVO 970 Plus was out performing them, almost bought that on Monday for $199, but saw a Sabrient Gen4 for $168 with $11 coupon on Amazon and went with that... NOW Amazon has the EVO 970 Plus for $169... which ever way the wind blows is the best value it seems. Although, Amazon has those "morphing" prices that seem to change often, probably based on your search habits. $169 for the EVO 970 Plus 1TB vs. $539 for the 2TB? Maybe Amazon tells vendors where the majority of sales volume is coming (ie 1TB) and competitors are getting more sales through via a certain price and miraculously the Samsung EVO price drops to match in a few days!! I'm sure Amazon analytics provided to their vendors play a part, probably be back to $239 after Xmas. Reply
  • Freeb!rd - Thursday, December 19, 2019 - link

    FYI, so the Sabrient Gen4 was $157.xx after coupon, still a great deal on a Gen4x4 drive for my new X570 motherboard. Reply
  • HarryVoyager - Thursday, December 19, 2019 - link

    The pricing is what makes all of this somewhat nuts. When I rebuilt my machine a month or so ago I ended up going with the 660p because I could get the 2TB version for around $170.

    While it isn't near the top of the heap for the destroyer, I don't do transfers of much more than a few GB at a time, and those are limited more by my Internet connection than by the drive.

    I've also got a professional grade SATA SSD, and despite its synthetic benchmarks being an order of magnitude lower than the 660p, I honestly can't tell a difference between what's installed on which. And I'm a heavy gamer who runs stuff that is notorious for slow load times and heavy RAM usuage. Even there, I'm not usually pulling more that 20Gb of data in a set, so it's just not a big difference.
  • dragosmp - Thursday, December 19, 2019 - link

    QLC was supposed to help with this segmentation. Hard to make a low end drive much cheaper just by not adding a 2$ DRAM chip and some PCB traces.

    Crucial P1 tends to kinda fulfill the QLC promise. It is sometimes at or around 80$ on offer for 1TB, has good warranty and performs quite well:
  • tlmiller76 - Saturday, December 21, 2019 - link

    I gotta disagree with the P1. I have one (1TB), and to be honest, I hate it. It's just...garbage in every way. I actually HAD an SX6000 Pro 1TB (unfortunately forgot to swap it out before I sold the laptop it was in) and it was so much better than the P1 they weren't even in the same zip code. Reply
  • zmatt - Saturday, December 21, 2019 - link

    IMO low end NVMe drives aren't worth considering at all. If you dont have the money for a Samsung Evo then dont both because you aren't really seeing the benefits. Obviously this doesn't apply in the case of a laptop or SFF where you may not have a choice. Reply
  • TheUnhandledException - Wednesday, December 18, 2019 - link

    It would be nice is low end NVMe drives were significantly cheaper but at least right now they are not. I don't really see the rationale for paying 2% less and getting 40% lower performance. Reply
  • sean8102 - Monday, February 3, 2020 - link

    I upgraded from a 256GB SATA Samsung 840 Pro (my first SSD ever) to the HP EX 920 1TB and love it. Never thought I'd end up going with a HP SSD but their EX 9x0 product line is great. Thinking of getting another NVME drive just for games and going with the EX 950. Reply

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