Crucial BX500 SSD Review: The DRAMless Invasion Continues

SSDs are dirt cheap this holiday season because the market is flooded with excess flash and companies are getting more aggressive with pricing. Prices have declined so drastically that you can now supercharge your PC with 500GB of flash for a mere $70 or pay roughly half that for 250GB. Now there's almost no excuse to use an HDD for your operating system and applications, and new drives like the Crucial BX500 are designed to bring prices even lower.

Crucial's BX500 is the successor to its popular BX300 line of SSDs. Like the company's mainstream MX500 brand, the BX500 skips over the 400-naming scheme. But, unlike the MX500, the BX500 doesn't offer much of an upgrade path over its predecessor.

The BX series is a streamlined, no-frills SSD with fewer accessories and features than the MX series. Crucial launched the BX series to tempt buyers into purchasing flash when other options in the market were too expensive. The original BX100 came with 16nm planar (2D) MLC flash and a Silicon Motion (SMI) controller. That was Crucial’s first SSD with an SMI controller, and that trend continues with the BX500. The new SSD uses the new SM2258XT four-channel SSD controller paired with Micron’s latest 64-Layer 3D TLC flash.

The base SM2258 is a good SATA SSD controller, and it offers impressive performance and reliability if it’s paired with the right flash. But it needs an expensive DRAM package for caching.

The SM2258XT, known as the XT model, combats this by removing the need for DRAM. This allows the SSD to store the critical flash translation layer directly on the flash instead of in a DRAM buffer. This lowers prices by a few dollars, but it also results in lower performance. NAND isn't as fast as DRAM, and the constant read/write modifications to the flash translation layer are a strenuous task. As a result, performance can be rather unflattering–even falling into hard drive territory.


ProductCrucial BX500 120GBCrucial BX500 240GBCrucial BX500 480GB
Pricing$26.99 $42.95 $69.99
Capacity (User / Raw)120  / 128
240 / 256480 / 512
Form Factor2.5" 7mm2.5" 7mm2.5" 7mm
Interface / ProtocolSATA 6.0 Gb/s / AHCISATA 6.0 Gb/s / AHCISATA 6.0 Gb/s / AHCI
ControllerSilicon Motion SM2258XTSilicon Motion SM2258XTSilicon Motion SM2258XT
NAND FlashMicron 64L TLCMicron 64L TLCMicron 64L TLC
Sequential Read540 MB/s540 MB/s540 MB/s
Sequential Write500 MB/s500 MB/s500 MB/s
Random ReadN/AN/AN/A
Random WriteN/AN/AN/A
Endurance40 TBW80 TBW120 TBW
Part NumberCT120BX500SSD1CT240BX500SSD1CT480BX500SSD1

Crucial’s BX500 provides up to 540/500 MB/s of sequential read/write throughput, but that can drop to an average of just 100 MB/s during a sustained workload. Crucial doesn't disclose random 4K IOPS performance, likely due to unimpressive performance, but we'll measure it on the following pages.

The BX500 is available in 120GB, 240GB, and 480GB capacities, just like the BX300 did before it. The BX500 currently sells for ~$0.22-per-GB for the 120GB model and $0.15-per-GB for the 480GB.

A three-year warranty and affordable prices designate the BX500 an entry-level SSD, but its rather low write endurance epitomizes its rank. The BX500's endurance rating starts at 40 TBW (Terabytes Written) and spans up to 120 TBW. Those are among the lowest endurance ratings on the market. Surprisingly, the BX500's endurance is even lower than its predecessor.

A Closer Look

The BX500’s case is made of thin metal and plastic. That keeps it lightweight, but the plastic gives it a cheap feel, which stands in stark contrast to its predecessor and the MX series. It connects to the host via a SATA 6GB/s connection.

Taking the casing apart reveals a 1/4 sized PCB, which is another way to reduce costs while still keeping compatibility with the 2.5" form factor. The SM2258XT resides near the connector for the best signal, and the 64-Layer 3D TLC flash is distributed among four emplacements (two on each side). Raw NAND capacity is 51GB, but after over-provisioning the user addressable space is just 480GB. That drops to 446GB of addressable space after you format the drive in Windows.


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