The WD Blue SN500 defies expectations. Its basic specifications say it's an entry-level NVMe drive: only two PCIe lanes (so it can't possibly exceed 2GB/s), a DRAMless controller that isn't using the NVMe Host Memory Buffer feature either, and a tiny SLC write cache. And our review sample is a 250GB model, which is the smallest drive capacity that can come close to offering decent performance when using just a handful of modern high-capacity NAND flash dies.

What we are accustomed to seeing from low-end NVMe drives is peak performance that's impressively high compared to SATA, but with caveats in the form of severely reduced performance in suboptimal conditions. What makes or breaks a low-end DRAMless SSD (even on NVMe) is usually not the question of how abysmal its worst case performance is, but whether that worst-case performance can be avoided during real-world usage.

The WD Blue SN500 doesn't buckle under the pressure of our most intense tests, and it performs surprisingly well on The Destroyer even when compared against some high-end NVMe models of similar capacity. The SN500's SLC cache is tiny, but the performance after the cache is full is pretty good for a 250GB drive, and it's not noticeably interrupted or degraded by garbage collection cycles. Compared to the other small entry-level NVMe SSDs we've tested, the SN500 is a clear winner. It doesn't come out ahead in every single test, but the overall performance profile is much more consistent. The SN500 at its worst is still a decent SSD.

The WD Blue SN500 is not a high-end NVMe drive and it is not at all hard to find cases where the typical high-end NVMe drive with a PCIe x4 connection is much faster than the SN500. But on the tests with more realistic IO patterns, the gap between the SN500 and the top tier of drives isn't huge.

Western Digital was late to the game with in-house NVMe SSD controllers, but they clearly took the time to get it right. Both the high-end WD Black and mainstream WD Blue SSD product lines (and their OEM counterparts) are now using controllers based on their own controller architecture, and both instantiations of that architecture seem to be very successful for a first-generation release. The two products offer very different performance, but most of the time they have very similar power efficiency that puts them at or near the top of the charts. For the slower WD Blue SN500, that excellent efficiency usually means it's drawing less than 2W under load, though it can occasionally be pushed all the way up to 2.5W. The OEM drive that the SN500 is derived from was intended to fit into the thinnest and lightest notebooks and tablets, and it looks like Western Digital achieved that goal without making any horrible sacrifices (except to maximum drive capacity).

We didn't have a 250GB sample of the older SATA-based WD Blue SSD on hand to compare against, but the 250GB SN500 had no trouble matching or exceeding the performance of the 1TB WD Blue SATA SSD. Since performance generally scales with capacity, this is an illustration both of how good the SN500 is and how ready the mainstream SSD market segment is to break free of the limitations of a SATA interface.

At current pricing, the WD Blue SN500 isn't quite ready to push SATA SSDs out of the market, but it does make it very easy to step up to NVMe without regrets or worries. However, as usual there are some even faster drives for sale in basically the same price range, including the HP EX920 (Silicon Motion SM2262) and the Team MP34 (Phison E12 controller) that we will be reviewing soon. If Western Digital can push the price of their entry-level NVMe drive all the way down to SATA prices, they'll have a very successful product on their hands.

Power Management


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  • Marlin1975 - Friday, April 19, 2019 - link

    Actually not bad for one that does not have any large external buffer. That and this is the 250gb model so the 500 should perform a little better as well. Reply
  • Dragonstongue - Friday, April 19, 2019 - link

    970 Evo Plus quite stands out for NVME based drives at ~$35 more for same size (just did a price check, amazon, 500gb for this vs 970 evo plus)
    so while "on paper" this appears great price, is still in very tough ground with ample contendors such as crucial with their p3 ( I believe it was called) countless samsung entries and the like.

    for an extra ~$30-$40 seems like "normally" is just not worth it when can do for ones self (such as clock up the slower product, tweaking voltages and the like) when it comes to a "paper" difference and more or less proven real world data this is not all that good a price.

    IMO is we take even a high performance HDD as a regular car speed, sata ssd (even highest performance) still is like an expensive supercar speed difference, the next jump would be the nvme based ones which are like top fuel dragsters (at best) but few tracks let them breathe proper and have to deal with engine problems (throttling etc) that normal drive do not have to deal with AND more $$$$$$..

    top fuel costs $$$$, do you ALWAYS see this speed, nope, but when you do, is wonderful, when you do not, it becomes a "so why did I pay that much more for little gain and loss in capacity as well as specific motherboards to tap the advantage" etc etc.

    kudos to WD, but alas, the margins are so very narrow and expected performance so high is near a non starter for all companies.

    I feel the "new standard" for storage should be @500gb for performance and capacity reasons with 1tb prefered (even a 250nvme + whatever size SSD flash in a raid internal no driver required fashion .. I always liked concept of hybrid drives, why not use hybrid memory styles to leverage as well, instead of saddling fast memory with spinning rust, use high speed low endurance flash with lower speed high endurance other flash.

    they do pci-e basd, nvme based, sata based etc etc, all have own benefit and detriment. I personally love sata based, leave the motherboard real estate for other things, they should do a further rendition of sata for the hole outs (like me and others whom have a variety of reasons)
    if they can patch pci-e to nvme, why not use sta 6 (like current) but tap x2 or x4 pci-e lanes to it as well, let us call it SATA-X, backwarrds compatible with Sta 6g to sata 1 ofc, this would allow some sata or whatever drives up their speed but use a familiar/durable/more widespread form factor.

    if all nvme based drives would work in all board or they would not interfere with mobo, not have throttle issues because of dog meta cooling designs (motherboard AND drive maker often enough) it would not be as much an issue, I like sata drive for such reasons, mainly can look "nicer" tend to be much more durable, that much less costly etc etc.

    anyways, if WD could do 500 for the price of the 250, that would be most excellent, but as the pricing is, mehhh, overall nice rounded performance with no real shortcomings compared to many others even some of the much more $ drives are not as "rounded" for this they at least did very well at, that much should be said.

    like Crucial with MX100, MX500, Samsung with the 800 through 970s (sata and nvme ofc) there are levels that are nice to hit, this SN500 is very much on that edge, up the performance a tough more, reduce price a touch (keep say $40 or better gap between this and the 970 evo plus) then this is that new "leg"

    crucial 100/mx500 are more "budget" compared to the "sometimes" faster sammy 8xx/9xx drives, sammy ofc got the speed and endurance markers out there, this "could be" that leg of "rounded performance" just like the mx500 or sammy 8xx/9xx evo ^.^
  • sonny73n - Saturday, April 20, 2019 - link

    Is this a comment or an essay? Reply
  • Hul8 - Saturday, April 20, 2019 - link

    "Stream of consciousness" is a style, but usually only applied to fiction. Reply
  • LMonty - Sunday, April 21, 2019 - link

    Haha! He just needed to get it out of his system :) Reply
  • npz - Saturday, April 20, 2019 - link

    $40+ more (for the 500GB) is not that much more at all. Like just avoid going out to dinner once or twice and you'll easily save that much. A PCIE x4 NVME slot is a precious slot in most machines that shouldn't be wasted on a gimped x2 drive.

    FYI I just the 250GB Samsung 970 EVO Plus at Fry's on sale a week or so ago for $59
  • RSAUser - Monday, April 22, 2019 - link

    Going out to eat twice? Is that a joke? I can go out to eat 4/5 times here for $40. Locale matters and you have no clue as to what others earn. Reply
  • Thud2 - Saturday, April 20, 2019 - link

    Can you elaborate? Reply
  • Jorgp2 - Sunday, April 21, 2019 - link

    Pretty sure this is targeted mostly at OEMs Reply
  • DyneCorp - Wednesday, April 24, 2019 - link

    The MX500 is on par with the 860 EVO. SSDs with Micron 64-layer 3D TLC NAND and the SM2262 controller (HP EX920 and ADATA SX8200) absolutely destroy Samsung 9 series NVMe SSDs in certain metrics.

    The initial price of any product is always high. The SN500 will drop in price. In fact, its not even selling at its suggested retail price from most retailers.

    And by the way, comparing SSDs to motor vehicles is ridiculous. Please stop.

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