Crucial M550 512GB 2-Drive SSD RAID Report

Introduction

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When Crucial launched their M500 series, they paved the way for low cost, high capacity SSDs. Last year, we were looking at $1/GB as a good price for an SSD. Today, we are looking at $0.50/GB for a mainstream SSD. As enthusiasts, we look at more than just pricing when it comes to choosing our solid state storage devices. We want superior performance every bit as much as we want low cost per GB.

The M500 delivered from a cost perspective like no other; however, it comes up woefully short in the performance department, and it is really out of the question for enthusiast implementation. The enthusiast crowd is a segment of the consumer pool that spends a lot of money to own hardware that delivers bleeding edge performance.

Crucial designed the M550 from the ground up to deliver compelling enthusiast level performance. The M550 is the first SSD to tap Marvell's newest SSD controller, the 88SS9189. Marvell's 88SS9189 improves on the performance of its predecessor, the 88SS9187, and delivers new features like DEVSLP for improved battery life.

Crucial's M550 has a host of built-in features that help separate it from other enthusiast class SSDs. The M550 supports AES 256-bit hardware encryption that meets TCG Opal 2.0 and IEEE-1667 standards. Microsoft's eDrive is also supported. In addition, the M550 is equipped with onboard capacitors that provide host power loss protection.

Crucial's M550 is the third drive in a row that I've reviewed that is built on IMFT 20nm NAND Flash. We are finding that IMFT NAND Flash delivers superior scaling in comparison to competing Toshiba NAND Flash. What this means is that while Toshiba flash-based SSDs typically outperform IMFT flash-based SSDs on a single drive basis, the superior scaling of IMFT flash can deliver a superior performing array, which is exactly what happened when we reviewed Intel's 730.

The M550's specifications look great on paper; now let's find out what the M550 has under the hood in real life.

Specifications, Pricing and Availability, Drive Details & Test System Setup

Specifications, Pricing and Availability

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Crucial's M550 Series 2.5-inch SATA III SSD is available in four capacity sizes: 128GB, 256GB, 512GB, and 1TB. Specifications list the 512GB M550 as having a bandwidth performance of up to 550 MB/s sequential reads and 500 MB/s sequential writes. 4kB random read performance is listed at up to 95,000 IOPS, and 4kB random write performance is listed at up to 85,000 IOPS.

PRICING: You can find the Crucial M550 512GB for sale at the bottom of this page. The prices listed are valid at the time of writing, but can change at any time. Click the link/s to see the very latest pricing for the best deal.

All M550 models have a three-year warranty, ship with a 7mm to 9.5mm adapter bracket, and Crucial provides Acronis data migration software via a download.

Because this is a RAID review, we are going to focus on performance rather than features. For a more in-depth look at the Crucial M550's feature set, I will refer you to Chris Ramseyer's extensive review of Crucial's M550 Series SSD.

Drive Details – Crucial M550 Series 512GB SSD

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Crucial packages their M550 in an attractive blue flip-top box. There is a picture of the drive on the top of the box.

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The bottom of the box is colored white and grey. The contents of the box are listed and diagramed.

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The box contains just the drive and a plastic spacer.

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The bottom and sides of the drive's enclosure are formed from a single piece of cast aluminum. There is an attractive blue sticker centered on the bottom face of the drive's enclosure.

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The top of the drive is formed from a piece of sheet aluminum. A manufacturer's sticker lists the drive's capacity, shipping firmware, model number, serial number' and various other relevant information.

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Here's what the drive looks like completely disassembled. On this side of the PCB, there are eight Micron 20nm BGA NAND packages, one DRAM package, a row of small capacitors, and a Marvell 88SS9189 Flash Processor. A thermal conducting pad is affixed to the bottom of the drive's cast aluminum enclosure. The thermal pad contacts the drive's controller and DRAM package. There are an additional eight NAND packages on the opposite side of the PCB.

Test System Setup

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- Drive Properties

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The majority of our testing is performed with our test drive/array as our boot volume. Our boot volume is 75% full for all OS Disk "C" drive testing to mimic a typical consumer OS volume implementation. We are using 64k stripes for our 2-3 drive arrays, 32k stripes for our 4-6 drive arrays. Write caching is enabled, and Windows buffer flushing is disabled.

All of our testing includes charting the performance of a single drive as well as RAID 0 arrays of our test subjects. We are utilizing Windows 8.1 64-bit for all of our testing.

PRICING: You can find the Crucial M550 (512GB) for sale below. The prices listed are valid at the time of writing but can change at any time. Click the link to see the very latest pricing for the best deal.

United States: The Crucial M550 (512GB) retails for $299.99 at Amazon.

Canada: The Crucial M550 (512GB) retails for CDN$309.98 at Amazon Canada.

Australia: The Crucial M550 (512GB) retails for $519.99 AUD at Mighty Ape Australia.

New Zealand: The Crucial M550 (512GB) retails for $552.99 NZD at Mighty Ape NZ.

Synthetic Benchmarks – ATTO, Anvil Storage Utilities, CrystalDiskMark & AS SSD

ATTO

Version and / or Patch Used: 2.47

ATTO is a timeless benchmark used to provide manufacturers with data used for marketing storage products.

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Write transfers ramp up quicker than read transfers. Read/write parity is achieved at 64kB transfers. Read transfers max out at 1.086 GB/s, while write transfers max out at 0.9683 GB/s.

Sequential Write

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Write performance is second only to our EVO array.

Sequential Read

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Sequential read transfers ramp up slower than the rest of the arrays on our chart.

Anvil Storage Utilities

Version and / or Patch Used: RC6

Anvil's Storage Utilities is a storage benchmark designed to measure the storage performance of SSDs. The Standard Storage Benchmark performs a series of tests; you can run a full test or just the read or write test, or you can run a single test, i.e. 4k QD16.

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Approaching 10,000 points, our 2-drive array is delivering awesome performance, especially with writing data.

Read IOPS through Queue Depth Scale

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Read performance is lower than most of the arrays on our chart.

Write IOPS through Queue Scale

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Our M550 array is pumping out exceptional write performance.

CrystalDiskMark

Version and / or Patch Used: 3.0 Technical Preview

CrystalDiskMark is disk benchmark software that allows us to benchmark 4k and 4k queue depths with accuracy.

Note: Crystal Disk Mark 3.0 Technical Preview was used for these tests since it offers the ability to measure native command queuing at 4 and 32.

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Sequential read performance and random 4k write performance is outstanding.

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512k read performance stands out in comparison to the other arrays on our chart.

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4k random write performance is considered one of the most important performance metrics, and our M550 array delivers the goods.

AS SSD

Version and / or Patch Used: 1.7.4739.38088

AS SSD determines the performance of Solid-State Drives (SSD). The tool contains four synthetic as well as three practice tests. The synthetic tests are to determine the sequential and random read and write performance of the SSD.

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With the last of our synthetic testing completed, let's move to our light usage model testing that will give us a better idea of what's under the hood of our M550 array.

Benchmarks (Trace Based OS Volume) - PCMark Vantage, PCMark 7 & PCMark 8

Light Usage Model

We are going to categorize these tests as indicative of a light workload. If you utilize your computer for light workloads like browsing the web, checking emails, light gaming, and office related tasks, then this category of results is most relevant for your needs.

PCMark Vantage - Hard Disk Tests

Version and / or Patch Used: 1.2.0.0

The reason we like PCMark Vantage is because the recorded traces are played back without system stops. What we see is the raw performance of the drive. This allows us to see a marked difference between scoring that other trace-based benchmarks do not exhibit. An example of a marked difference in scoring on the same drive would be empty vs. filled vs. steady state.

We run Vantage three ways. The first run is with the OS drive/Array 75% full to simulate a lightly used OS volume filled with data to an amount we feel is common for most users. The second run is with the OS volume written into a "Steady State" utilizing SNIA's guidelines (Rev 1.1). Steady state testing simulates a drive/array's performance similar to that of a drive/array that has been subjected to consumer workloads for extensive amounts of time. The third run is a Vantage HDD test with the test drive/array attached as an empty, lightly used secondary device.

OS Volume 75% Full - Lightly Used

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OS Volume 75% Full - Steady State

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Secondary Volume Empty - Lightly Used

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As you can see, there's a big difference between an empty drive/array, one that's 75% full/used, and one that's in a steady state.

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The important scores to pay attention to are "OS Volume Steady State" and "OS Volume 75% full." These two categories are most important because they are indicative of typical of consumer user states.

When a drive/array is in a steady state, it means garbage collection is running at the same time it's reading/writing. There is a huge difference in performance between a single drive and a 2-drive array.

Our M550 array delivers the third best steady state performance we've measured.

PCMark 7 - System Storage

Version and / or Patch Used: 1.4.00

We will look to the Raw System Storage scoring for RAID 0 evaluations because it's done without system stops and therefore allows us to see significant scoring differences between drives/arrays.

OS Volume 75% Full - Lightly Used

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Toshiba's Q Series Pro is hard to beat in this test. Our M550 array performs quite similarly to our 730 series array; both arrays utilize 20nm IMFT flash.

PCMark 8 - Storage Bandwidth

Version and / or Patch Used: 1.2.157

We use the PCMark 8 Storage benchmark to test the performance of SSDs, HDDs, and hybrid drives with traces recorded from Adobe Creative Suite, Microsoft Office, and a selection of popular games. You can test the system drive or any other recognized storage device, including local external drives. Unlike synthetic storage tests, the PCMark 8 Storage benchmark highlights real-world performance differences between storage devices.

OS Volume 75% Full - Lightly Used

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Again, our M550 array performs most similarly to our 730 array. Both IMFT flash-based arrays easily outpace the Toshiba flash-based arrays. The M550 and 730 arrays are scaling better than the Toshiba flash-based arrays.

Benchmarks (Secondary Volume) – Disk Response & Transfer Rates

Iometer – Disk Response

Version and / or Patch Used: 1.1.0

We use Iometer to measure disk response times. Disk response times are measured at an industry accepted standard of 4k QD1 for both write and read. Each test is run twice for 30 seconds consecutively, with a 5 second ramp-up before each test. The drive/array is partitioned and attached as a secondary device for this testing.

Write Response

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Read Response

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Average Disk Response

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Write response times benefit most from RAID 0 because of write caching. There is a slight latency increase in read response times for an array vs. a single drive. This is where the similarity between our 2 IMFT arrays ends. Our 730 array has superior latency, but our M550 array does not.

DiskBench - Directory Copy

Version and / or Patch Used: 2.6.2.0

We use DiskBench to time a 28.6GB block (9,882 files in 1,247 folders) of mostly incompressible random data as it's transferred from our OS array: to our test drive/array. We then read from a 6GB zip file that's part of our 28.6GB data block to determine the test drive/array's read transfer rate. The system is restarted prior to the read test to clear any cached data, ensuring an accurate test result.

Write Transfer Rate

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Read Transfer Rate

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Our M550 array delivers our best read transfer performance to date. Write transfer performance comes in last place; however, there is not a whole lot of difference between first and last.

Benchmarks (Secondary Volume) – PCMark 8 Extended

Futuremark PCMark 8 Extended – Consistency Test

Heavy Usage Model

We consider PCMark 8's consistency test to be our heavy usage model test. This is the usage model most enthusiasts, heavy duty gamers, and professionals fall into. If you do a lot of gaming, audio/video processing, rendering, or have workloads of this nature, then this test will be most relevant to you.

PCMark 8 has built-in, command line executed storage testing. The PCMark 8 Consistency test measures the performance consistency and the degradation tendency of a storage system.

The Storage test workloads are repeated. Between each repetition, the storage system is bombarded with a usage that causes degraded drive performance. In the first part of the test, the cycle continues until a steady degraded level of performance has been reached. (Steady State)

In the second part, the recovery of the system is tested by allowing the system to idle and measuring the performance with long intervals. (TRIM)

The test reports the performance level at the start, the degraded steady-state, and the recovered state, as well as the number of iterations required to reach the degraded state and the recovered state.

We feel Futuremark's Consistency Test is the best test ever devised to show the true performance of solid state storage in a heavy usage scenario. This test takes on average 13 to 17 hours to complete, and it writes somewhere between 450GB and 8000GB of test data, depending on the drive(s) being tested. If you want to know what an SSD's performance is going to look like after a few months or years of heavy usage, this test will show you.

Here's a breakdown of Futuremark's Consistency Test:

Precondition phase:

1. Write to the drive sequentially through up to the reported capacity with random data.

2. Write the drive through a second time (to take care of overprovisioning).

Degradation phase:

1. Run writes of random size between 8*512 and 2048*512 bytes on random offsets for 10 minutes.

2. Run performance test (one pass only).

3. Repeat 1 and 2 for 8 times, and on each pass increase the duration of random writes by 5 minutes.

Steady state phase:

1. Run writes of random size between 8*512 and 2048*512 bytes on random offsets for 50 minutes.

2. Run performance test (one pass only).

3. Repeat 1 and 2 for 5 times.

Recovery phase:

1. Idle for 5 minutes.

2. Run performance test (one pass only).

3. Repeat 1 and 2 for 5 times.

Storage Bandwidth

PCMark 8's Consistency test provides a ton of data output that we can use to judge a drive's performance.

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We consider steady state bandwidth (the blue bar) our test that carries the most weight in ranking a drive's performance. The reason we consider steady state performance more important than TRIM is that when you are running a heavy-duty workload, TRIM will not be occurring while that workload is being executed. TRIM performance (the orange and red bars) is what we consider the second most important consideration when ranking a drive's performance. Trace based consistency testing is where true high performing SSDs are separated from the rest of the pack.

A single M550 does not have compelling steady state performance, but our 2-drive array certainly does. Notice how a single M550 manages only 124 MB/s storage bandwidth in a steady state. The steady state performance of our 2-drive M550 array is well over double that of a single M550. This is what we mean by scaling; this is why a SATA based array delivers superior performance in an OS environment.

We retired our 840 Pro array from this testing due to its inferior performance. In its place, I thought it would be interesting to see how a PCIe SSD would fair against our top arrays. Comay's BladeDrive 480GB PCIe SSD has an advertised sequential read/write speed of 2000 MB/s. Sequential performance is nice for secondary attached storage, but in an OS disk environment, random 4k performance reigns supreme. The BladeDrive is no match for any of our arrays in an OS environment. I am of the opinion that until PCIe is RAID capable, it's not going to provide compelling OS disk performance.

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We chart our test subject's storage bandwidth as reported at each of the test's 18 trace iterations. This gives us a good visual perspective of how our test subjects perform as testing progresses.

Total Access Time (Latency)

Access time is the time delay or latency between a request to an electronic system and the access being completed or the requested data returned. Access time is how long it takes to get data back from the disk. We chart the total time the disk is accessed as reported at each of the test's 18 trace iterations.

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The M550 has higher latency than the rest of the drives on our chart in a steady state. As soon as our M550 array gets a break, TRIM does its job, and our M550 array finishes with the lowest latency of any array on our chart.

Disk Busy Time

Disk Busy Time is how long the disk is busy working. We chart the total time the disk is working as reported at each of the tests 18 trace iterations.

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When latency is low, disk busy time is low as well. Our M550 array is able to spend up to 3.5 times less time working than a single M550.

Data Written

We measure the total amount of random data that the drives are capable of writing during the degradation phases of the consistency test. The total combined time that degradation data is written to the drives is 470 minutes. This can be very telling. The better the drives can process a continuous stream of random data, the more data will be written.

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Our M550 array is able to write 1500 gigabytes of random data in 470 minutes. The M550's lack of overprovisioning and consumer pedigree conspire to deliver weak performance in this test. Drives like the 600 Pro and the 730K have enterprise DNA, and they are able to write continuous streams of random data many times faster than drives with consumer DNA. The ComayBlade is supposed to be a drive designed for enterprise class performance, yet it delivers very poor random write performance.

Final Thoughts

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Solid state storage is the most important performance component found in a modern system today. Without it, you do not even have a performance system.

Crucial has certainly stepped up its game. The M550 gives Crucial a competent enthusiast class offering. The last time Crucial had one of the top enthusiast class SSDs was many years ago when they delivered the world's first SATA 6Gb/s SSD, the C300.

As price per gigabyte for solid state storage continues to drop, SSDs are rapidly becoming a mainstream piece of hardware. A lot of SSDs on the market today are all about using the cheapest components available in order to keep profit margins high, or just to be able to compete with manufacturers that own NAND Fabs. Enthusiasts sometimes are taken in and purchase an SSD based solely on advertised sequential speed.

On the surface, most SSDs appear to have the same performance as one another; it's only when we dig deeper that we begin to see that some drives have vastly superior performance to others even though they carry virtually the same advertised specifications.

Our M550 array performed quite well and is an array I can recommend you own. For the price, an M550 array is very hard to beat. Crucial's M550 is really their response to Samsung's EVO, which has been dominating the market share of SSD sales for a while now. An M550 array will cost you about the same as a Samsung EVO array of the same capacity, but an M550 array will outperform an EVO array in an enthusiast setting. Beyond the performance, the M550 is superior to the EVO because the M550 has superior flash, period.

A single M550 performs fairly well, and an M550 array performs very well. The superior scaling of IMFT flash makes an M550 array a great choice for enthusiasts on a budget.

RAIDing two or more drives together provides you with storage that takes performance to the next level and is something I recommend you try. Think of it as the SLI of storage. Once you go RAID, there's no going back!

PRICING: You can find the Crucial M550 (512GB) for sale below. The prices listed are valid at the time of writing but can change at any time. Click the link to see the very latest pricing for the best deal.

United States: The Crucial M550 (512GB) retails for $299.99 at Amazon.

Canada: The Crucial M550 (512GB) retails for CDN$309.98 at Amazon Canada.

Australia: The Crucial M550 (512GB) retails for $519.99 AUD at Mighty Ape Australia.

New Zealand: The Crucial M550 (512GB) retails for $552.99 NZD at Mighty Ape NZ.