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PNY CS900 SSD vs WD PC SN520 256GB NVMe SSD

Buy the PNY CS900 if you are upgrading an older desktop or laptop that takes a 2.5-inch SATA drive. It costs far less: $21.36 at its lowest since November 2, versus $89.99 at neweggbusiness.com as of November 7, 2026, for the WD SN520. Buy the WD SN520 only if your machine has an M.2 2242 slot and you need NVMe speed.

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PNY
PNY CS900 Solid State Drive

PNY CS900 SSD

PNY CS900 Solid State Drive

4.8(13,000 ratings)
See all prices and details

Choose the PNY CS900 if you want the cheapest reliable way to replace a spinning hard drive in a SATA bay.

Pros
  • Very cheap: $21.36 at its lowest since November 2, 2026.
  • 550 MB/s read and 500 MB/s write beat any hard drive.
  • 2.5-inch SATA fits almost any desktop or older laptop.
  • Shock resistant, with no moving parts.
  • Secure Erase and end-to-end data path protection.
Cons
  • No DRAM cache, so sustained writes can slow down.
  • SATA speed caps it well below NVMe drives.
  • No encryption.
  • Won't fit M.2-only laptops.
Western Digital
Western Digital PC SN520 M.2 2242 256GB PCIe Gen3 x2 NVMe 1.3 64-layer 3D NAND Internal Solid State Drive (SSD) SDAPMUW-256G

WD PC SN520 256GB NVMe SSD

Western Digital PC SN520 M.2 2242 256GB PCIe Gen3 x2 NVMe 1.3 64-layer 3D NAND Internal Solid State Drive (SSD) SDAPMUW-256G

$89.99at neweggbusiness.comObserved at 8:52 AM
See all prices and details
Visit neweggbusiness.com

Choose the WD SN520 if your laptop or tablet has an M.2 2242 slot and you want NVMe read/write speed in a small, low-power drive.

Pros
  • 1600 MB/s write is roughly three times the CS900.
  • M.2 2242 size fits thin laptops and the Surface Pro X.
  • NVMe over PCIe Gen3 x2.
  • Low power draw suits battery-powered devices.
Cons
  • $89.99 at neweggbusiness.com as of November 7, 2026, is about four times the CS900's low.
  • Only one store lists it new.
  • 256GB fills fast with games or video.
  • M.2 2242 slots are uncommon; check yours before buying.

What separates them

PNY CS900 SSDWD PC SN520 256GB NVMe SSD
InterfaceSATA IIIPCIe Gen3 x2 NVMe 1.3
Form factor2.5 inchM.2 2242 (listed as M2 2230)
Write speed500 MB/s1600 MB/s
Read speed550 MB/sNot listed; NVMe Gen3 x2 is far faster than SATA
DRAM cacheNoneNot listed
Power draw2.2 W activeLow-power design
Price$21.36 low since November 2, 2026$89.99 at neweggbusiness.com as of November 7, 2026
FitDesktop and laptop SATA baysM.2 2242 slots only, including Surface Pro X

Price history

$89.99$21.36
Nov 2Nov 7
  • PNY CS900 SSD: lowest $21.36 on Nov 2 at BlueDogInk; $54.99 on Nov 6.
  • WD PC SN520 256GB NVMe SSD: lowest $87.65 on Nov 2 at Newegg.com; $89.99 on Nov 7.

Prices at every store

PNY CS900 SSD

  • AmazonCheck price at Amazon
  • WalmartCheck price at Walmart
  • Best BuyCheck price at Best Buy
Prices and history →

WD PC SN520 256GB NVMe SSD

  • neweggbusiness.comNew

    In stock

    $89.99Observed at 8:52 AM
    Visit neweggbusiness.com

Also available at

  • eBayCheck price at eBay
  • Newegg.comCheck price at Newegg.com

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Specs compared

SpecPNY CS900 SSDWD PC SN520 256GB NVMe SSD
TypeSolid State Drive, SSDSSD
UseInternalInternal
Device CompatibilityPC systemLaptop, Mac, PC, Laptop 3, Microsoft Surface Pr…
InterfaceSATA IIIM.2, NVMe
Write Speed500 MB/s1600 MB/S
NVMe SupportNoYes
PCIe SupportNoYes
Form Factor2.5 inchM2 2230
Design HighlightsNo moving partsHigh-speed, low-power
Power Consumption2.2 Watt (active)low-power
Wireless ConnectivityNo—
DurabilityShock resistant—
Show all 19 specsShow fewer specs
SpecPNY CS900 SSDWD PC SN520 256GB NVMe SSD
Read Speed550 MB/s—
CacheNo DRAM cache—
Data EncryptionNo—
Security HighlightsSecure Erase, End-to-end data path protection—
Typical UsersTech enthusiast, Creative professional, Enthusi…—
Power SourceCA—
RemovableNo—

What reviewers say

PNY CS900 SSD

  • 4.8 / 513,000 ratings

With 4.8 out of 5 from about 13,000 ratings, owners mostly treat the CS900 as a cheap, reliable way to speed up an old machine. Complaints center on sustained write speed and the lack of DRAM.

What people mention
  • SpeedPraisedOwners say boot times and app loading improve sharply over a hard drive.
  • ValuePraisedBuyers call it one of the cheaper ways to upgrade an older PC.
  • ReliabilityPraisedMany long-term owners report the drive keeps working without errors.
  • Sustained writesCriticisedLarge file copies slow down once the cache is exhausted.

WD PC SN520 256GB NVMe SSD

Owner feedback on the SN520 line is generally positive for reliability and laptop fit, with speed complaints centered on the x2 interface and small capacity. Most buyers use it as a boot or secondary drive rather than for heavy workloads.

What people mention
  • SpeedMixedOwners find it much faster than SATA but slower than Gen3 x4 drives on large transfers.
  • FitPraisedThe 2242 length is the reason many buyers pick it, since 2280 drives won't fit their laptops.
  • CapacityCriticised256GB is seen as tight once an OS, apps and a few games are installed.
  • PowerPraisedLow power draw is noted as friendly to laptop battery life and heat.

Questions and answers

Which is faster?
The WD SN520. Its 1600 MB/s write speed is about three times the CS900's 500 MB/s, and NVMe over PCIe beats SATA on reads too.
Which should I buy for an old desktop?
The PNY CS900. Old desktops have 2.5-inch SATA bays, not M.2 2242 slots, and the CS900 costs a fraction as much.
Is the WD SN520 worth the extra money?
Only if your device has an M.2 2242 slot and you move large files. At $89.99 versus $21.36 at their lows, the CS900 is far better value for everyday use.
Which lasts longer?
Neither listing gives endurance ratings or warranty terms, so there is no basis to pick one on lifespan. Both are shock resistant with no moving parts.
Will the SN520 fit my laptop?
Only if the laptop has an M.2 2242 slot. Many take 2280 instead, and the SN520 will not fit a 2.5-inch bay.
Does either have a DRAM cache?
The CS900 has no DRAM cache. The SN520 listing does not state one, so assume neither does.

More comparisons

  • Corsair Neutron 256GB vs Western Digital PC SN520 M.2 2242 256GB PCIe Gen3 x2 NVMe 1.3 64-layer 3D NAND Internal Solid State Drive (SSD) SDAPMUW-256G