When someone asks me which SSD to buy, I typically recommend getting the highest capacity they can afford from a reputable brand. Some budget drives should be avoided, especially at lower capacities, but most decent SSDs offer similar all-around performance. For the majority of consumers, the differences in pricing are more important than the differences in performance.
Right now, the Crucial M500 is one of the most affordable contenders. Crucial is the consumer brand of memory giant Micron, so it gets a family discount—and first dibs—on the latest and greatest flash memory. That’s a good recipe for success in the increasingly commoditized world of consumer SSDs, especially when one adds the strong reliability reputation Crucial has built over multiple generations of solid, er, drives.
We like the M500 480GB and 960GB a lot. Both offer decent all-around performance, and they’re very cheap per gig. We’re not as crazy about the 240GB variant, though. The M500 uses higher-density flash chips than most of its peers, and the 240GB model doesn’t have enough of them to saturate the controller’s NAND interface. The drive is notably slower in certain scenarios as a result, though it’s still much faster than mechanical storage.
Keenly aware of the M500 240GB’s handicap, Crucial has developed an updated family of SSDs that seems custom tailored to address it. The new M550 uses flash from the same 20-nm generation as its predecessor. However, the smaller capacities in the lineup employ lower-density NAND chips than the rest of family, so they should be able to wring more performance out of the controller.
In addition to tweaking the die configuration for lower capacities, the M550 is supposed to be faster than the M500 across the board. The new lineup’s 128GB-to-1TB spread offers a little more storage than the M500’s 120-to-960GB options, too. Let’s take a closer look.
A new spin on an old favorite
Instead of supplanting its predecessor, the M550 complements it. The old M500 has become noticeably cheaper in recent months, and the M550 slots in above it as a more premium solution.
Crucial’s latest hotness comes in the same form factors as its elder sibling: 2.5″, mSATA, and M.2. The top 1TB capacity is only available in 2.5″ form, though. The M.2 and mSATA versions are meant for notebooks and limited to 512GB and smaller capacities. We’re focusing our attention on the 2.5″ SATA family, which includes the following models:
|Capacity||Die config||Max sequential (MB/s)||Max 4KB random (IOps)||Endurance||Price||$/GB|
|128GB||16 x 8GB||550||350||90,000||75,000||72TB||$99.99||$0.78|
|256GB||32 x 8GB||550||500||90,000||80,000||72TB||$168.99||$0.66|
|512GB||32 x 16GB||550||500||95,000||85,000||72TB||$336.99||$0.65|
|1TB||64 x 16GB||550||500||95,000||85,000||72TB||$530.99||$0.51|
All the drives are built on 20-nm MLC NAND that rolls off of Micron’s production line. These chips store two bits per cell, just like the flash used on most modern SSDs.
Unlike the M500, which has 16GB (128Gb) flash chips throughout, the M550 series reserves those high-density dies for the 512GB and 1TB units. The 128GB and 256GB drives have smaller 8GB (64Gb) NAND to provide more independent chips for the controller to address simultaneously. Thus, the M550 256GB has the same amount of I/O parallelism as the 512GB version—and nearly identical performance specifications.
The 1TB variant has the same performance specs as the 512GB drive, suggesting that there’s little to be gained by adding more than 32 NAND dies. The write speed ratings for the 128GB model drop off substantially, though. That drive’s 16 dies just aren’t enough to saturate the controller.
Each M550 capacity offers a little more storage than the equivalent M500, but the amount of onboard flash hasn’t changed. It’s just partitioned differently, with more available to the user, less to the controller and its associated firmware.
Crucial expanded the amount of user storage by makin’ it rain… slightly less. Ahem. RAIN is a RAID-like redundancy scheme that uses parity to protect against data loss due to physical flash failures. In the M500, the RAIN stripe is set at 15:1, which monopolizes 17GB of flash on the 240GB version. That ratio has been scaled back to just 127:1 in the M550. If my math is correct, only 2GB of the M550 256GB’s total flash capacity is dedicated to parity data. Crucial passes the savings on to the user: the M500 reports 223GB of user-accessible storage in Windows, while the M550 256GB weighs in at 238GB.
SSDs with RAID-like data protection typically have slightly lower capacities, like the M500, or extra NAND dedicated to storing redundancy data, like the Intel 730 Series. The M550’s slimmed-down stripe is an interesting twist, and it was motivated by the lessons Crucial learned with the M500. The NAND platform is now more mature, Crucial says, and the company is confident it can meet reliability expectations with a scaled back RAIN implementation.
The M550 doesn’t just guard against data loss due to flash failures. It also features a layer of power-loss protection powered by onboard capacitors. If the power is cut unexpectedly, these caps should supply enough juice for the drive to complete pending writes and to shut down gracefully, without corrupting user data.
Much of the M550’s drive-level intelligence is part of custom firmware running on an off-the-shelf Marvell 88SS9189 controller chip. Crucial says there are “no substantial differences” between this chip and the 88SS9187 silicon in the M500. Like pretty much every other SSD controller, the Marvell solution has eight memory channels and a 6Gbps Serial ATA interface. 256-bit AES encryption is handled in hardware, and the firmware has the necessary hooks for Microsoft’s eDrive standard, in addition to the TCG Opal 2.0 and IEEE 1667 specs.
Despite the fact that the M550 uses largely identical controller and NAND technology to the old M500, the new drive is supposed to be faster. Crucial credits the M550’s “native write acceleration,” which doesn’t involve compression, NAND buffering, or DRAM-based caching. Unfortunately, the company doesn’t say what this native acceleration does entail.
In a moment, we’ll look how the M550’s performance compares to that of the M500 and a range of other competitors. There are a few more details to cover before we get to those results, including a couple of features targeted primarily at mobile users.
The M550 supports the DevSleep low-power state used by Windows 8’s connected standby mode. Crucial claims the drive pulls less than three milliwatts in this state, and it says active power consumption is less than 150 mW. Interestingly, the 2.5″, mSATA, and M.2 versions of the M550 all have similar power consumption ratings.
Adaptive thermal protection is the other feature aimed at mobile devices. If the M550 gets too hot, it throttles performance until thermals return to optimal levels. This capability is most important for notebooks and tablets, but it could also benefit cramped small-form-factor and all-in-one rigs. Desktop users with adequate system airflow probably don’t have to worry about their SSDs overheating.
Missing software and secretive SMART attributes
Most of the big-name SSD makers offer utility software that optimizes system settings, monitors drive health, and handles firmware updates. Crucial continues to be conspicuously absent from that club, but it sounds like software is in development. For now, M550 owners will have to resort to third-party utilities. These applications typically don’t perform optimization or firmware updates, but they can monitor the drive via its SMART attributes.
Crucial doesn’t make monitoring with third-party tools particularly easy, though. The screenshot below displays the SMART attributes accessible to HD Sentinel. Note the numerous “Vendor-specific” attributes with no additional explanation.
Similarly obfuscated attributes populate the M500’s SMART data. Fortunately, the vendor-specific entries are described in an attribute decoder ring (PDF) available on Crucial’s site. The M550’s attributes are the same as those for the M500’s latest MU03 firmware. They provide information on reallocated sectors, program and erase failures, error correction and RAIN recovery events, and total host writes. That’s important data, so I’m puzzled why much of it is hidden behind meaningless labels. Users shouldn’t need a separate document to analyze basic drive statistics.
SMART attributes are most useful for wear monitoring, but most users probably don’t have to worry about burning through the M550’s available flash cycles. The drive is rated for 72TB of total writes, which works out to 40GB per day for five years. This endurance specification is fairly generous for a consumer-grade drive. It also matches the rating attached to the M500.
Crucial expects both drives to continue working after they’ve surpassed 72TB of writes. However, the warranty expires after the endurance limit is reached or three years have passed, whichever comes first.
The results of our ongoing endurance experiment suggest that the M550 should be able to write a lot more than 72TB. Thus far, we’ve written hundreds of terabytes to a stack of MLC-based SSDs. We’ve exceeded all their endurance ratings several times over, and the drives have reported barely any bad blocks, let alone more serious failures.
Premium SSDs usually have higher write endurance ratings and longer warranty coverage than cheaper models, so it’s a little surprising that the M550 matches its predecessor on both fronts. To be fair, though, the M550 is priced more like a mid-range drive than a high-end offering. The 256GB version is set to sell for $169, which is a lot cheaper than the $200+ stickers typically attached to premium SSDs. The old M500 effectively resides in budget territory; the 240GB version rings in at only $120 right now, which is the lowest price I see for a drive of that size.
At the top of the range, the M550 1TB is priced at $531, or $0.51/GB. That’s cheaper than the $556 street price of the Samsung 840 EVO 1TB, but only just. The old M500 is cheaper still, with the 960GB version priced at only $440, or $0.46/GB.
Test notes and methods
All three terabyte-class SSDs are included in our performance results, so that will be a fun battle to watch. We’ve run the M550 256GB through the gauntlet, as well. Pay attention to how that drive fares against not only its counterpart in the M500 family, but also other contenders in the sweet spot of the market.
Here’s a full rundown of the SSDs we tested, along with their essential characteristics.
|Corsair Force Series GT 240GB||NA||SandForce SF-2281||25nm Intel sync MLC|
|Corsair Neutron 240GB||256MB||LAMD LM87800||25nm Micron sync MLC|
|Corsair Neutron GTX 240GB||256MB||LAMD LM87800||26nm Toshiba Toggle MLC|
|Crucial M500 240GB||256MB||Marvell 88SS9187||20nm Micron sync MLC|
|Crucial M500 480GB||512MB||Marvell 88SS9187||20nm Micron sync MLC|
|Crucial M500 960GB||1GB||Marvell 88SS9187||20nm Micron sync MLC|
|Crucial M550 256GB||256MB||Marvell 88SS9189||20nm Micron sync MLC|
|Crucial M550 1TB||1GB||Marvell 88SS9189||20nm Micron sync MLC|
|Intel 335 Series 240GB||NA||SandForce SF-2281||20nm Intel sync MLC|
|Intel 520 Series 240GB||NA||SandForce SF-2281||25nm Intel sync MLC|
|Intel 730 Series 480GB||1GB||Intel PC29AS21CA0||20nm Intel sync MLC|
|OCZ Vertex 4 256GB||512MB||Indilinx Everest 2||25nm Micron sync MLC|
|OCZ Vertex 450 256GB||512MB||Indilinx Barefoot 3 M10||20nm Intel sync MLC|
|SanDisk Extreme II 240GB||256MB||Marvell 88SS9187||19nm SanDisk Toggle SLC/MLC|
|Samsung 840 Series 250GB||512MB||Samsung MDX||21nm Samsung Toggle TLC|
|Samsung 840 EVO 250GB||256MB||Samsung MEX||19nm Samsung Toggle TLC|
|Samsung 840 EVO 500GB||512MB||Samsung MEX||19nm Samsung Toggle TLC|
|Samsung 840 EVO 1TB||1GB||Samsung MEX||19nm Samsung Toggle TLC|
|Samsung 840 Pro 256GB||512MB||Samsung MDX||21nm Samsung Toggle MLC|
|Seagate 600 SSD 240GB||256MB||LAMD LM87800||19nm Toshiba Toggle MLC|
|Seagate Desktop SSHD 2TB||64MB||NA||24nm Toshiba Toggle SLC/MLC|
|WD Caviar Black 1TB||64MB||NA||NA|
Crucial sent us the 128GB and 512GB versions of the M550, too, but I was out of the lab traveling for a chunk of last week, so there wasn’t enough time to test those drives fully. Fortunately, there was just enough time to run them through DriveBench 2.0, our long-term test of real-world I/O performance.
Our main body of results contains some of the most popular SSDs around. The bulk of the field is in the 240-256GB range, and most of those drives have 32-die configurations with no performance handicaps. For the Crucial M500 and Samsung 840 EVO, whose lower-capacity flavors are tagged with slower specs, we have results for multiple capacities, including the fastest models. You can find full reviews of most of the drives in our storage section.
The solid-state crowd is augmented by a couple of mechanical drives. WD’s Caviar Black 1TB represents the old-school hard drive camp. Seagate’s Desktop SSHD 2TB is along for the ride, as well. The SSHD combines mechanical platters with 8GB of flash cache, but like the Caviar Black, it’s really not a direct competitor to the SSDs. The mechanical and hybrid drives are meant to provide additional context for our SSD results.
The rest of this page is filled with nerdy details about system and test configurations. If you’re familiar with how we do things around here, feel free to skip ahead to the benchmark results.
We used the following system configuration for testing:
|Processor||Intel Core i5-2500K 3.3GHz|
|CPU cooler||Thermaltake Frio|
|Motherboard||Asus P8P67 Deluxe|
|Platform hub||Intel P67 Express|
|Platform drivers||INF update 220.127.116.110
|Memory size||8GB (2 DIMMs)|
|Memory type||Corsair Vengeance DDR3 SDRAM at 1333MHz|
|Audio||Realtek ALC892 with 2.62 drivers|
|Graphics||Asus EAH6670/DIS/1GD5 1GB with Catalyst 11.7 drivers|
|Hard drives||Seagate Desktop SSHD 2TB with CC43 firmware
WD Caviar Black 1TB with 05.01D05 firmware
Corsair Force Series GT 240GB with 1.3.2 firmware
Corsair Neutron 240GB with M206 firmware
Corsair Neutron GTX 240GB with M206 firmware
Crucial M500 240GB with MU03 firmware
Crucial M500 480GB with MU03 firmware
Crucial M500 960GB with MU03 firmware
Crucial M550 256GB with MU01 firmware
Crucial M550 1TB with MU01 firmware
Intel 335 Series 240GB with 335s firmware
Intel 520 Series 240GB with 400i firmware
Intel 730 Series 480GB with XXX firmware
OCZ Vector 150 256GB with 1.1 firmware
OCZ Vertex 450 256GB with 1.0 firmware
SanDisk Extreme II 240GB with R1131
Samsung 830 Series 256GB with CXM03B1Q firmware
Samsung 840 Series 250GB with DXT07B0Q firmware
Samsung 840 EVO 250GB with EXT0AB0Q firmware
Samsung 840 EVO 500GB with EXT0AB0Q firmware
Samsung 840 EVO 1TB with EXT0AB0Q firmware
Samsung 840 Pro Series 256GB with DXM04B0Q firmware
Seagate 600 SSD 240GB with B660 firmware
|Power supply||Corsair Professional Series Gold AX650W|
|OS||Windows 7 Ultimate x64|
Thanks to Asus for providing the systems’ motherboards and graphics cards, Intel for the CPUs, Corsair for the memory and PSUs, Thermaltake for the CPU coolers, and Western Digital for the Caviar Black 1TB system drives.
We used the following versions of our test applications:
- Intel IOMeter 1.1.0 RC1
- HD Tune 4.61
- TR DriveBench 1.0
- TR DriveBench 2.0
- TR FileBench 0.2
- Qt SDK 2010.05
- MinGW GCC 4.4.0
- Duke Nukem Forever
- Portal 2
Some further notes on our test methods:
- To ensure consistent and repeatable results, the SSDs were secure-erased before almost every component of our test suite. Some of our tests then put the SSDs into a used state before the workload begins, which better exposes each drive’s long-term performance characteristics. In other tests, like DriveBench and FileBench, we induce a used state before testing. In all cases, the SSDs were in the same state before each test, ensuring an even playing field. The performance of mechanical hard drives is much more consistent between factory fresh and used states, so we skipped wiping the HDDs before each test—mechanical drives take forever to secure erase.
- We run all our tests at least three times and report the median of the results. We’ve found IOMeter performance can fall off with SSDs after the first couple of runs, so we use five runs for solid-state drives and throw out the first two.
- Steps have been taken to ensure that Sandy Bridge’s power-saving features don’t taint any of our results. All of the CPU’s low-power states have been disabled, effectively pegging the 2500K at 3.3GHz. Transitioning in and out of different power states can affect the performance of storage benchmarks, especially when dealing with short burst transfers.
The test systems’ Windows desktop was set at 1280×1024 in 32-bit color at a 75Hz screen refresh rate. Most of the tests and methods we employed are publicly available and reproducible. If you have questions about our methods, hit our forums to talk with us about them.
CrystalDiskMark — transfer rates
TR regulars will notice that we’ve trimmed a few tests from our usual suite of storage results. The drives were all benchmarked in the same way, but we’ve excluded the results for tests that have grown problematic or less relevant over time. This abbreviated format should be a little easier to digest until our next-gen storage suite is ready.
First, we’ll tackle sequential performance with CrystalDiskMark. This test runs on partitioned drives with the benchmark’s default 1GB transfer size and randomized data. I’ve color-coded the results to make the M500 and M550 easier to spot.
Crucial’s latest SSD is faster than its predecessor in both tests. The difference is only about 30MB/s with reads, but it’s double that with writes—and much larger for the 240-256GB drives. The M550 256GB more than doubles the sequential write speed of the M500 240GB.
Likely thanks to its tweaked die configuration, the M550 256GB barely trails its 1TB sibling. Both are competitive with the fastest SSDs we’ve run through this test, and they easily outclass the mechanical and hybrid drives at the bottom of the pile.
HD Tune — random access times
Next, we’ll turn our attention to random access times. We used HD Tune to measure access times across multiple transfer sizes, and we’ve presented the data in a couple of ways. The line graph shows the results for all the transfer sizes for only the Crucial SSDs, the Seagate hybrid, and the WD mechanical drive. We’ve also busted out the 4KB and 1MB transfers sizes into bar graphs that compare the Crucial SSDs to their solid-state counterparts. The mechanical and hybrid drives screw up the scale for the bar graphs, and the SSDs end up stacked on top of each other in the line graphs, so the two-pronged approach works best.
Besides, we’re really looking at two separate things here. The first is highlighted by the line graph, which shows the vast gulf in access times between solid-state and mechanical drives. SSD access times are orders of magnitude quicker than those of traditional hard drives, at least with smaller transfer sizes. The delta is pretty huge at the largest transfer size, too.
Now, notice the relative parity between the solid-state drives in the bar graphs. Even though the field looks a little spread out in the 4KB test, the differences amount to small fractions of a millisecond there and in the 1MB test. The M550 isn’t appreciably faster or slower than any of the other SSDs.
Similar subplots are found in our random write results, but with a couple of twists.
Unlike in the random read test, the Desktop SSHD’s write access times are notably slower than those of the SSDs. The hybrid still beats the mechanical drive hands down, but it lags behind the SSDs more than in the random read test.
The right side of the line graph shows a difference between the M500 240GB and the other Crucial drives. Let’s see what the bar graphs tell us.
The 1MB results show the M500 240GB well behind most of the field. Whatever ails that drive doesn’t seem to affect the M550 256GB, which hangs near the front of the pack with its 1TB sibling. Both M550s have a slight edge over the M500 480GB and 960GB.
All of these SSDs are very responsive with 4KB random writes. The differences there amount to a few microseconds at best, just like in the random read tests.
TR FileBench — Real-world copy speeds
Filebench, which was concocted by TR’s resident developer Bruno “morphine” Ferreira, runs through a series of file copy operations using Windows 7’s xcopy command. Using xcopy produces nearly identical copy speeds to dragging and dropping files using the Windows GUI, so our results should be representative of typical real-world performance. We tested using the following five file sets—note the differences in average file sizes and their compressibility. We evaluated the compressibility of each file set by comparing its size before and after being run through 7-Zip’s “ultra” compression scheme.
|Number of files||Average file size||Total size||Compressibility|
The names of most of the file sets are self-explanatory. The Mozilla set is made up of all the files necessary to compile the browser, while the TR set includes years worth of the images, HTML files, and spreadsheets behind my reviews. Those two sets contain much larger numbers of smaller files than the other three. They’re also the most amenable to compression.
To get a sense of how aggressively each SSD reclaims flash pages tagged by the TRIM command, the SSDs are tested in a simulated used state after crunching IOMeter’s workstation access pattern for 30 minutes. The drives are also tested in a factory fresh state, right after a secure erase, to see if there is any discrepancy between the two states. There wasn’t much of one with the M550, so we’re only presenting the used-state scores.
The M550 looks especially strong here. The 256GB and 1TB drives perform similarly, and they’re within striking distance of the front of the pack. That said, the 1TB version is a step behind its counterpart in the Samsung 840 EVO family. It’s still a fair bit faster than the M500 960GB, though.
At the lower end of the capacity spectrum, the M550 256GB is a lot faster than the M500 240GB. Those extra NAND dies really come in handy, allowing the M550 to trade blows with the other top drives in the 240-256GB range.
Notice that the M550 has competitive copy speeds with different types of files. Unlike the SandForce-based SSDs, it doesn’t perform appreciably better with compressible data.
TR DriveBench 2.0 — Disk-intensive multitasking
DriveBench 2.0 is a trace-based test comprised of nearly two weeks of typical desktop activity peppered with intense multitasking loads. More details on are available on this page of our last major SSD round-up.
We measure DriveBench performance by analyzing service times—the amount of time it takes drives to complete I/O requests. We’ll start with an overall mean service time before slicing and dicing the results. The M550 128GB and 512GB drives are also included here.
Overall, the M550 looks like a nice improvement over its predecessor. The mean service time is down for each capacity, though the 256GB unit appears to be a bit sluggish compared to the larger M550 variants. At least it’s more responsive than the 128GB version, which has half the internal parallelism of the 256GB drive—and a much slower mean service time.
The M550 512GB and 1TB score especially well in DriveBench 2.0 overall. The flagship model has one of the quickest mean service times we’ve recorded in this test, and the 512GB variant isn’t far behind.
There are millions of I/O requests in this trace, so we can’t easily graph service times to look at the variance. However, our analysis tool does report the standard deviation, which gives us a sense of how much the individual service times vary from the mean.
This metric suggests that the M550’s access times are not only quicker than those of its predecessor, but also more consistent. Again, the 512GB and 1TB versions are the most competitive overall. The smaller drives exhibit more variance, especially the 128GB one.
Let’s split DriveBench 2.0 service times into reads and writes to get a better sense of what’s going on.
The M550 256GB’s mean read service time doesn’t look too bad. The drive falls much further behind with writes, though, and so does its 128GB sibling.
That said, the M550 drives have quicker service times than their M500 counterparts pretty much across the board. The only exception is the tie between the mean read service times of the M500 240GB and the M550 256GB. NAND-level parallelism apparently has little effect on read performance, at least for those drives in this test.
All the SSDs execute the vast majority of DriveBench requests in one millisecond or less—too little time for end users to perceive. We can also sort out the number of service times longer than 100 milliseconds, which is far more interesting data. These extremely long service times make up only a fraction of the overall total, but they’re much more likely to be noticeable.
The M550 looks much better than the M500 here, and its advantage grows as the capacity rises. That’s a fine accomplishment. However, it’s worth noting that the older Crucial SSDs exhibit far more extremely long service times than their peers. Even with the M550 cutting those numbers dramatically, the new drives still trail the top dogs by substantial margins. The M550 256GB in particular logs way more extremely long write service times than alternatives from other vendors.
Of course, the M550 128GB is even worse. It takes longer than 100 milliseconds to execute about 1.3% of all DriveBench requests. This drive has the same number of NAND dies as the M500 240GB, but it posts nearly three times as many extremely long write service times.
Our IOMeter workload features a ramping number of concurrent I/O requests. Most desktop systems will only have a few requests in flight at any given time (87% of DriveBench 2.0 requests have a queue depth of four or less). We’ve extended our scaling up to 32 concurrent requests to reach the depth of the Native Command Queuing pipeline associated with the Serial ATA specification. Ramping up the number of requests also gives us a sense of how the drives might perform in more demanding enterprise environments.
We run our IOMeter test using the fully randomized data pattern, which presents a particular challenge for SandForce’s write compression scheme. We’d rather measure SSD performance in this worst-case scenario than using easily compressible data.
There’s too much data to show clearly on a single graph, so we’ve split the results by drive maker. You can compare the performance of the Crucial M550 to that of the competition by clicking the buttons below each graph.
Instead of presenting the results of multiple access patterns, we’re concentrating on IOMeter’s database test. This access pattern has a mix of read and write requests, and it’s similar to the file server and workstation tests. The results for these three access patterns are usually pretty similar. We also run IOMeter’s web server access pattern as part of our standard suite of tests, but it’s made up exclusively of read requests, so the results aren’t as applicable to real-world scenarios. Our own web servers log a fair amount of writes, for example.
Before we start comparing the solid-state drives, notice that the lines for the mechanical and hybrid offerings hug the horizontal axis. Once again, the SSDs offer an entirely different class of performance.
There are big performance differences between the SSDs, too, but the M550 drives are often on the losing end of those contests. The Corsair Neutrons, Intel 730 Series, OCZ Vector 150, and Seagate 600 SSD all achieve higher I/O rates across the bulk of this test.
The M550 at least looks better when compared to the older SandForce-based drives and the various Samsung 840 incarnations. The 1TB version is faster than the 256GB one, and both have an edge over their respective rivals in the M500 family. In fact, the M550 256GB largely equals the performance of the M500 960GB.
Before timing a couple of real-world applications, we first have to load the OS. We can measure how long that takes by checking the Windows 7 boot duration using the operating system’s performance-monitoring tools. This is actually the first test in which we’re booting Windows off each drive; up until this point, our testing has been hosted by an OS housed on a separate system drive.
Level load times
Modern games lack built-in timing tests to measure level loads, so we busted out a stopwatch with a couple of reasonably recent titles.
The SSDs are on largely even footing throughout our load time tests. No more than about a second separates the fastest SSDs from the slowest ones, making the differences between them awfully difficult to notice.
Our mechanical drive has much longer load times than the SSDs, highlighting a key benefit of solid-state storage. The Seagate hybrid largely narrows that gap, but it’s still a little bit slower than the SSDs.
We tested power consumption under load with IOMeter’s workstation access pattern chewing through 32 concurrent I/O requests. Idle power consumption was probed one minute after processing Windows 7’s idle tasks on an empty desktop.
The M550’s power consumption is similar to that of the M500. The differences between them—and indeed the differences between all the SSDs—are too small to be significant for desktop systems. For mobile applications, the M550’s power consumption is reasonably low. It’s not the lowest-power SSD we’ve tested, but I wouldn’t worry about it draining your laptop battery, either.
Before we weigh in with our final verdict, we’ll indulge a couple of our famous value scatter plots. These plots use an overall performance score derived by comparing how each drive stacks up against a common baseline. This score is based on a subset of the performance data from our full suite, but with CrystalDiskMark’s sequential transfer rates substituted for older HD Tune scores. (More details about how we calculate overall performance are available here.)
We’ve mashed up the overall scores with per-gigabyte prices from Newegg. (The M550 isn’t selling online as I write this, so Crucial’s suggested retail prices were used for those drives.) The best solutions will gravitate toward the upper left corner of the plot, which signifies high performance and low prices.
Solid-state and mechanical storage have vastly different performance and prices, and those disparities make the main plot a little busy. Click the buttons below the plot to switch between all the drives and a cropped look at just the SSDs—and keep in mind that we’ve trimmed the axes for the SSD-only plot.
Most of the SSDs are grouped within a similar overall performance band. The prices per gig vary quite a bit more than the performance scores.
At the top of the M550 lineup, the 1TB drive nearly overlaps with the Samsung 840 EVO 1TB. These two drives have virtually identical overall performance scores and price tags. Also, the M550 delivers a nice boost in performance over the M500 960GB for only a modest increase in cost per gigabyte.
Things don’t look so rosy for the M550 256GB, whose sluggish performance in a handful of tests hurts its overall score. This drive is slower overall than most of its peers, including the Samsung 840 EVO 250GB, which is also cheaper per gig. The M550 256GB is much faster overall than the M500 240GB, at least, but its higher price tag somewhat negates that advantage. Several SSDs offer higher overall performance than the M550 256GB at lower prices.
The scatter plots don’t tell the whole story, of course. The M550 256GB does a lot more to address the M500 240GB’s most glaring weaknesses than the increase in the overall score suggests. And even if the newer drive doesn’t match the all-around performance of the top-tier SSDs, it’s still way better than mechanical storage. I’d just be hesitant to pick it over the equivalent EVO and some of the other SSDs that hang around the $170 mark
The M550 1TB is much easier to endorse. This drive doesn’t suffer from the same performance pitfalls as the 256GB variant, and it costs a fair bit less per gig. The 840 EVO 1TB may have faster performance in some tests, but the M550 wins in others, it has better built-in data protection, and its MLC NAND should have superior endurance than the EVO’s three-bit TLC flash. Those perks make the M550 better suited for write-heavy workloads and folks who are paranoid about data integrity.
What about the M500 960GB, which is nearly as fast as the M550 1TB but $91 cheaper? That’s tempting, and I wouldn’t blame anyone who bought this older drive. However, spending more on the M550 buys extra capacity, better all-around performance, and a big reduction in the number of extremely long service times logged by our long-term test of real-world I/O. That’s worth the premium for me. It’s also worth our coveted Editor’s Choice award.
In a sense, the M550 is only a minor update to the M500. Little has changed in the controller, and apart from some new die configurations, the NAND is essentially the same. You get a little more speed and a little more storage for a higher price. Part of me finds that formula a little boring, perhaps because I spend far too much time looking at new SSDs. But I also remember that the M500 launched with much higher prices about a year ago; the 240GB version was priced at $210, and the 960GB cost $600. The M550 beats those marks handily, and with better performance to boot. That might not be the most exciting progress in the tech industry, but it’s pretty awesome for consumers looking to upgrade from mechanical drives or to make more substantial investments in solid-state storage.