WD Blue SSD vs Samsung 860 Evo (comparison)

Samsung introduced their new 860 EVO for the budget SSD market in late 2017. They are designed to offer better performance at similar prices compared to last year’s 850 EVO.

The 6 Gbps SATA interface is an improvement over the previous generation (which had no technology of its own) and Marvell controller-equipped models (notably, Samsung’s own 470), but still lags behind some other companies using more modern solutions like Phison E7 or Silicon Motion SM2258XT.

Samsung 860 Evo vs WD Blue – Dissecting the Differences

The new 860 Pro will likely only be released by Western Digital in mid-2018, whereas Samsung started shipping their entry-level 4 TB model in January this year already.

This is not to say that the Pro model will be significantly better or worse than the 860 EVO, it is just more of a marketing distinction.

8-channel architecture on WD’s SSDs vs 4-channel design on Samsung’s drives

Typically, the higher number of memory channels allows for increased parallelism and therefore improved performance. However, this comes at the expense of potentially reduced compatibility with motherboards that have weak CPU I/O lanes – you need all cores / IO lanes available to utilize all eight memory channels fully. In some cases, performance might also be lower if two DIMMs are paired into one channel instead of operating independently.

For these reasons, drive producers tend to either go with 4-channel designs (eg Crucial’s MX500) or 8-channel (eg WD Blue).

However, there are not enough scenes where it would make a difference. Most people would be hard-pressed to tell the difference between two identical drives operating on 4 vs 8 channel configurations in real life.

WD’s total throughput is higher compared to Samsung’s drive because both rely on SATA 3 interface.

The protocol overhead might result in lower read speeds at smaller file sizes for WD, but this should not matter that much in practice since both drives are already above 500 MB/s with large files. It also seems like firmware / Windows 10 caching algorithms do their job well enough that even sequential performance does not drop all that much when starting applications/games, so once again it seems unlikely to matter.

Samsung’s latest 860 Evo features 256 MB of DRAM cache, just like their flagship Pro models. However, the firm has opted for standard MLC memory instead of TLC. This is significant because, in theory at least, MLC should be more durable and fail less often than TLC (which was found to wear out much faster than expected), although most companies market the same “3 bits per cell” as a feature regardless.

Samsung claims durability ratings of 200 TBW for 250 GB drives and 500 TBW for 4 TB ones (note that this is not written on retail packaging or its website).

WD Blue is using 3D TLC NAND by Toshiba with 64-layer BiCS architecture that improves endurance and performance. The manufacturer ratings are comparable: 100 TB for 250 GB and 400 TB (less than the 860 Evo) for 1 TB and 4 TB models.

Besides — potentially — higher endurance, there is no reason to prefer one over another unless you want a higher warranty period or peace of mind provided by a longer official support timeline (5 vs 3 years).

Similarities do not end here either. Both drives rely on SATA interface (although WD Blue works with legacy PS/2 connection as well), come in 2.5-inch/7mm form factor, and work with Windows, macOS 10.13+, Linux Fedora 25, Debian 8.6+ out of the box in AHCI mode only (which means no TRIM, but Intel/Linux has a built-in cleanup command that is better than nothing).

WD Blue SSD vs Samsung 860 Evo: Performance

The WD Blue is a budget drive aimed at people who do not need high-end performance or extra features. It comes with a fairly aggressive ~120 GB write amplification factor due to its TLC memory and relatively large SLC cache (more on this below), which makes it slower for random writes compared to other drives (Samsung’s 860 Evo as well as Crucial MX500, the latter also using 64L 3D TLC like WD’s drive).

Samsung SSD performance

Samsung has been utilizing a partial SLC caching scheme on their EVO series ever since they introduced it in 2015. Only recently it became clear that the 960 Pro (yes, they skipped 1) models also rely on DRAM (albeit much more powerful one) for caching. This is the reason why their drives seem to perform better in benchmarks compared to their rivals with identical hardware.

Samsung 860 Evo 250 GB  is rated for up to 550 MB/s sequential reads and 520 MB/s writes (sequential QD32), involving up to 100K random read IOPS and 90K write IOPS at QD256. The TLC-based WD Blue is somewhat behind (~530 / 450).

Similarities continue when comparing performance across multiple file sizes: Samsung has a small advantage at smaller sets, but once you go past 4 KB, WD Blue is clearly ahead.

Not surprisingly, there are also no problems when using both SSDs in RAID 0 array:

The scores actually improved compared to a single drive and were up to 2 GB/s in sequential reads / 1.5 GB/s writes depending on file size.

WD Blue 3D NAND SATA SSD  is a fine drive that can be recommended to anyone who needs a budget-friendly option based on good-old TLC memory for everyday computing tasks (documents, casual gaming, web browsing) and does not want to make too many compromises. Samsung 860 Evo fares even better by offering higher performance at a similar price, although it comes with a larger footprint and lacks support for legacy systems out of the box.

The WD Blue will also do great in RAID 0 configuration if you are looking for extra speed without spending too much on more expensive drives.

Regardless, both drives are recommendations for anyone looking to upgrade their traditional HDD to an affordable and reliable SSD that will last for years (or even decades).

However, when you consider the fact that Crucial MX500  also uses TLC NAND memory in addition to DRAM cache with SLC buffer (which is not as large as Samsung’s one but still big enough) and costs significantly less than WD Blue, it becomes clear why Samsung’s drive has some tough competition for its place under the sun.

Especially considering how long it takes Samsung to release new models with slightly better performance. A newer version of 960 Evo would be preferred over this one due to support for 4KB random read/write operations, but it’s still good enough for its price.

Samsung 860 Evo 250 GB  is rated for up to 550 MB/s sequential reads and 520 MB/s writes (sequential QD32), involving up to 100K random read IOPS and 90K write IOPS at QD256. The TLC-based WD Blue is somewhat behind (~530 / 450).

similarities continue when comparing performance across multiple file sizes: Samsung has a small advantage at smaller sets, but once you go past 4 KB, wd blue is clearly ahead.

WD Blue SSD vs Samsung 860 Evo: Conclusion

Both drives have been around for a while now and their prices have become very similar over time, so it’s unlikely that one can find a much better deal than these two.

When looking at performance, WD Blue 3D NAND SATA SSD comes out slightly ahead of its closest rival from Samsung when handling large files (sequential transfers), but struggles with smaller ones due to its small SLC cache.

This might not be much of an issue when transferring large folders or processing images in Adobe Photoshop, but when working with 4K video, the difference is significant.

Ryan MacWha

I am Ryan! I write about performance-driven and reliable SSDs. I can save your time in decision-making. How about you?