Introduction & Drive Details
A little over a month ago, we crowned Samsung's 980 Pro 1TB as the best performing flash-based SSD we've ever tested. Like almost everyone else, we figured we would be looking at an upcoming showdown between Phison, Samsung, and maybe SMI for the Gen4 SSD performance crown. Well, stop the presses because, on Friday of last week, an unexpected package showed up at the lab that changes everything we assumed.
While everyone has been talking about Gen4 SSDs by Samsung, Phison, and SMI, WD has been quietly perfecting a Gen4 contender of their own. I mean, yeah, we all heard about it, but Western Digital's incoming Black SN850 Gen4 SSD did not seem to garner much attention. This is probably because their Gen3 flagship SSD, the WD Black SN750, made its living at the bottom of the performance ladder. In fact, we rank Western Digital's own WD Blue SN550 4-channel DRAMless value SSD far above the WD Black SN750 in terms of real performance (user experience).
We assumed the WD Black SN850 would likely be another low-performance drive with good to great sequential numbers, much like its predecessor. Man were we ever wrong. We should again point out for the millionth time that contrary to popular mythology, sequential numbers have little to do with what makes an SSD fast. Do you need proof? Consider for a moment the fastest consumer SSD ever made, Intel's 905P, only reaches sequential speeds of 2,700/2300 MB/s.
In a nutshell, we are trying to convey that if you want the performance crown, you better bring a lot more than eye-popping sequential numbers to the table. What you better be bringing if you even want to be mentioned in the conversation is random performance at low queue depths. Western Digital's WD Black SN850 brings it all. It is the most potent mix of everything that makes a flash-based SSD fast that we've experienced to date.
Let's take a close look at why we have crowned (for now) the 1TB WD Black SN850 the best performing flash-based SSD by the numbers.
The black-themed drive is an attractive single-sided design which we prefer.
Jon's Test System Specifications
- Motherboard: ASUS ROG Crosshair Hero VIII Wi-Fi (buy from Amazon)
- CPU: AMD Ryzen 9 3900X (buy from Amazon)
- Cooler: ARCTIC Liquid Freezer II 280 (buy from Amazon)
- Memory: ADATA XPG Z1 DDR4 3800MHz 16GB (buy from Amazon)
- Video Card: Sapphire Radeon RX Vega 64 (buy from Amazon)
- Power Supply: Corsair AX1000 (buy from Amazon)
- Case: InWin X-Frame
- OS: Microsoft Windows 10 Pro 64-bit (buy from Amazon)
Free SSD Software
WD Dashboard/Acronis for WD
The WD dashboard is as good as it gets for an SSD Toolbox. It has everything, and we mean everything you could ever want from an end-user perspective. WD also offers free Acronis cloning software that you can get with just a click of the tools tab.
Take note of "Gaming Mode" because you will want that enabled for best performance. Additionally, be sure to enable write caching and, importantly, for all SSDs, disable write-cache buffer flushing for best performance.
Synthetic Benchmarks: CDM & Anvils
We have no issues hitting WD's factory sequential read spec of 7,000 MB/s. We don't quite get to 5,300 MB/s sequential writes (because of our more demanding user state - OS Disk 50% filled) but close enough. The 1TB WD Black SN850 trounces our previous sequential champion, the 980 Pro, easily. That's great, but we like what we see with Q1T1 randoms even better. (3-lab records) Impressive.
Anvil's Storage Utilities
A total read score of 10K is on par with Samsung's 980 Pro and absolute domination of the rest of the flash-based competition. The total write score is the best we've ever seen, as is an overall score of over 26K where it becomes the first SSD to ever best the mighty Optane 905p. (2-lab records)
921K random read IOPS is another lab record for a consumer SSD. Amazing.
Synthetic Benchmarks: AS SSD & ATTO
The 980 Pro manages to put up a little bit of a fight by delivering a better write score, but that's now what we are interested in at all. We care about the total read score, and the SN850 delivers the best we've seen from a 1TB SSD to date. (1-lab record)
The SN850 essentially ties the 980 Pro, this time when programming data sequentially at 128K. However, again, we do not care about write performance nearly as much as read performance, where the SN850 delivers another lab record.
Real-World Testing: Transfer Rates & Gaming
Samsung's 980 Pro remains lab champ by a mere 51 MB/s. However, as always, we are far more interested in how fast data can be served to the host.
Serving data is more important than programming it in the consumer space, and the SN850 delivers yet another lab record while doing important things. (Consumer tasks are 80% read 20% write)
Game Level Loading
Western Digital is marketing the WD Black SN850 as a gaming drive. While not the absolute best, it is just a fraction of a second off the best we've seen from a flash-based SSD and slightly better than the 980 Pro.
Real-World Testing: PCMark 10 Storage Tests
PCMark 10 Storage Test is the most advanced and most accurate real-world consumer storage test ever made. There are four different tests you can choose from; we run two of them.
The Full System Drive Benchmark and the Quick System Drive Benchmark. The Full System Drive Benchmark writes 204 GB of data over the duration of the test. The Quick System Drive Benchmark writes 23 GB of data over the duration of the test. These tests directly correlate with user experience. Of the two tests, we feel that the Quick System Drive Test most accurately replicates a typical user experience.
PCMark 10 Full System Drive Benchmark
Here we go! Absolutely stunning heavy workload performance. Prosumers pay attention because the WD Black SN850 is exactly what you need. It is even better than the 980 Pro. (Lab record)
PCMark 10 Quick System Drive Benchmark
Of all the benchmarks we run, this is where we want to see exceptional performance most. Hey, look, another lab record for all flash-based SSDs. This seals the deal. Western Digital's WD Black SN850 is by far the best performing flash-based consumer SSD as of 11-9-2020. We are inclined to think that it will remain so for a good while. We shall see.
We had no idea that Western Digital was cooking up an SSD that would prove to be the best performing consumer SSD to date. They have never done anything like that before. That's always been the realm of other big names. Well, not anymore, Western Digital; you have the performance crown - you earned it.
Hey, look, 1,000,000 random read IOPS, as advertised. Amazing.
Sequential numbers don't mean a thing. This is what actually matters, user experience. The SN850 will, other than Optane, deliver overall the most gratifying PC experience we've seen to date. And not by a little bit, but by a lot.
Looking back at our test results, the WD Black SN850 1TB is like a nonstop highlight reel, but a few results stand out even more than the rest. Anvil's at 26K is mind-bending performance that even bests Optane. As demonstrated by our transfer testing, serving data to the host at over 3,500 MB/s is another first for any SSD. Gaming performance is among the best we've ever seen. And finally, where it matters most, Western Digital's WD Black SN850 1TB delivers record-breaking performance no matter the workload.
As it stands today, we can confidently say the WD Black SN850 is the best performing flash-based consumer SSD money can buy.
- User experience
- 1,000,000 IOPS/7,000 MB/s
The Bottom Line
A straight 100% rating pretty much says it all!