Which is faster for everyday use?

The WD Blue SN5100, by a wide margin. Its 7100 MB/s read and 1000K IOPS random read dwarf the M4's 500 MB/s and 45K IOPS, so boot times and app loads are much quicker.

Is the WD Blue SN5100 worth the extra $15?

Yes for most buyers. For about $15 more you get 4x the capacity and far higher speed. The M4 only makes sense if your system has no M.2 slot.

Will the Crucial M4 fit my laptop?

Only if your laptop takes a 9.5mm 2.5-inch SATA drive. Many newer laptops are M.2-only, in which case the SN5100 is the one that fits.

The SN5100 is rated at 600 TBW, which is a published endurance figure. Crucial lists 1.2 million hours MTBF for the M4 but no TBW rating, so the SN5100 is the safer bet on stated endurance.

Can I use the SN5100 in a desktop?

Yes, if the motherboard has an M.2 2280 PCIe slot. Most boards from the last several years do.

Is the M4 a good deal at $179.99?

No, unless you specifically need a 2.5-inch SATA drive. You pay nearly the same as the 1TB SN5100 for a quarter of the capacity and much slower speeds.

WD Blue SN5100 1TB SSD vs Crucial M4 256GB SSD

The WD Blue SN5100 is the clear pick for almost every buyer. It is a current PCIe 4.0 NVMe drive with roughly 14x the sequential read speed and 4x the capacity of the Crucial M4, and it costs only about $15 more. The M4 is a 2011-era SATA drive at $179.99 at Newegg as of November 8, 2026, versus $194.61 at Dealtargets.com for the SN5100 as of the same date. Buy the M4 only if you need a 2.5-inch SATA drive for an old machine and nothing else fits.

Today the WD Blue SN5100 1TB SSD costs $8.09 less at its best price.

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