There wasn't any reason to change the M550's chassis. It's not the nicest-looking enclosure I've ever opened up, but it's all-metal, and it works well. My biggest complaint is probably that the foil label scratches easily, making it hard to get a good picture.
The PCB (Front)
This is the 512 GB drive's PCB, and it looks pretty similar to the M500. Most notable are the eight placements of Micron flash. Each package hosts 32 GB of capacity, with two 128 Gb dies each.
The 256 GB model is configured with as many packages. But instead of utilizing 128 Gb parts, it's built on a foundation of 64 Gb dies. With all else equal, the two SSDs should perform pretty much identically (Crucial wasn't able to send a sample for testing).
The PCB (Back)
All of the action happens on the back of the PCB, where you see the other memory packages, along with Micron's data cache and Marvell's updated controller.
In a play to reduce power consumption, that cache is low-power DRAM. The 1024 GB M550 comes equipped with 1024 MB of LPDDR3, while the pictured 512 GB drive includes 512 MB. Crucial's 256 GB M550 also includes 512 MB, though it really only uses half of that. Most of the space is used for mapping anyway; only a few MB of the capacity goes to caching information.
A familiar bank of surface-mount capacitors provide the M550 with power-loss protection, which you don't always see on desktop-oriented drives. Intel's SSD 730 was the most recently-reviewed example of an enthusiast drive with this functionality, and its solution is stouter than Crucial's. However, it's also found on a drive that costs twice as much per gigabyte as the M500.
This is IM Flash Technologies' L85 NAND, used by both Intel and Micron.
Marvell's 88SS9189 controller is more of a black box. There isn't much technical data about it available, but we believe it's manufactured using a smaller process by TSMC. Almost without question, it exists as a refinement of the 88SS9187, and we know it helps propel the M550 to better benchmark results.
- Introducing Crucial's M550 Performance SSD Family
- Inside Of Crucial's M550 SSD
- RAIN: Protecting Against Small NAND Failures
- Test Setup And Benchmarks
- Results: Sequential Performance
- Results: Random Performance
- Results: Tom's Storage Bench v 1.0
- Results: Tom's Storage Bench v 1.0, Continued
- Results: PCMark 7 And PCMark Vantage
- Results: TRIM Testing
- Results: Power Consumption
- M550 SSD: Evolving Value Into High Performance