◄ incase you missed it here is part 1Results: Enterprise Workload PerformanceOur next set of tests simulates different enterprise-oriented workloads, including database, file server, Web server, and workstation configurations.
The database workload (also categorized as transaction processing) involves purely random I/O. Its profile consists of 67% reads and 33% writes using 8 KB transfers.
I have to say I was a little surprised at the outcome of this test. Not only does Micron's M500DC blow by the entry-level offerings, but it also maintains a clear advantage over the rest of the field, too. The drive's excellent write performance is enough to make for its lower read rate.
In the file server workload, which consists of 80% random reads of varying transfer sizes, the M500DC gives us another strong showing, only trailing SanDisk's Optimus Eco at high and low queue depths. In the sweet spot (a queue depth between eight and 32), the M500DC is a clear winner.
The Web server workload (100% reads of varying transfer sizes) exposes one of the M500DC's weaknesses: pure read-based transactions. At higher queue depths, it's only able to match the P400m, while trailing the other contenders by a wide margin.
Finally, the workstation benchmark (80% reads, 80% random) puts Micron's M500DC back near the top. While it consistently trails Intel's SSD DC S3700 and SanDisk's Optimus Eco, it clearly beats the rest of the field.
Overall, the M500DC performs well in our mixed workload tests, only falling behind on the read-only metrics. These results should be even higher if we retest using Micron's 240 and 480 GB models. I'd say this is a considerable accomplishment for a drive that owes a lot of its design to a cost-optimized consumer SSD.
Results: Sequential Performance
Once again, the M500DC posts modest, but not great read performance. At 450 MB/s, it trails SanDisk's Optimus Eco and Seagate's 600 Pro by nearly 100 MB/s.
Sequential write performance is a bit worse. At 405 MB/s, the M500DC consistently beats its specification. But that still puts it near the bottom of the field. It's also nowhere near the Eco's crazy 560 MB/s.
Clearly, sequential performance is not one of the M500DC's strong suits. Fine-tuning SSD firmware is a series of give and takes. Bolstering throughput in one measurement often decreases it in another one. Fortunately, Micron is clear about the workloads this new drive is intended to address. While it excels in a number of enterprise-oriented tasks, the best we can say about the M500DC in sequential transfers is that it's adequate.
Results: Enterprise Video Streaming PerformanceVideo streaming is a demanding workload within the enterprise space. Companies want more HD streams with higher bit-rates and no stuttering. A storage solution well-suited for enterprise-class video delivery has completely different capabilities than something designed for databases. At the end of the day, you're basically looking for exceptional large-block sequential write performance. You also need a high level of consistency that traditionally isn't seen from consumer SSDs.
As we saw in our sequential testing, the M500DC does not post a very high sequential write rate. But what it lacks in throughput is more than made up for by consistency.
The graph above is highly averaged, with each point representing 800 MB, but the consistency is still evident. In fact, the range from peak to trough is roughly +/- 1% of the average. We run this test 100 times on each drive, and every cycle looks exactly like the chart we're showing you.
Due to limits of Excel, I can't chart out the individual 8 MB writes, but I assure you that they're incredibly consistent. In fact, in order to maintain 400 MB/s (which is 25 MB/s higher than Micron's spec), we only need a 32 MB buffer. That is outstanding.
New: Power Consumption, DetailedPower consumption, with regard to solid-state storage, is an interesting topic. In most reviews, you typically see power averaged for idle, in a sleep state, and under load. Although that's useful, those numbers don't give you the entire story of how SSDs use power. In order to fully understand draw, we need instrumentation to accurately measure voltage and current. In our testing, we use a high-precision DC source that is capable of sourcing 30 W at 5 V. It is also able to, with a high level of accuracy, measure the output voltage and current draw at 5000 samples per second. The source is then spliced into a SATA power cable, allowing us to calculate consumption.
Now that we can measure the exact power draw of any SATA-attached SSD, interesting trends start showing up. Every attribute, from power-up, to sequential and random workloads, and even the TRIM command shows up as a distinct power level unique to each drive. Power consumption is also intrinsically linked to performance. Of course, this shouldn't be news to anyone familiar with the way electronic components work. Generally, the harder you push a piece of hardware, the more power it draws. What is news, at least to us, is that performance variations happening at the sub-millisecond level are observable in a drive's power draw.
This first chart illustrates a full battery of benchmarks on Micron's M500DC. At the start, you can see power-on levels, including in-rush. Once the device is recognized by the system, it enters an active idle state. Next, we run our different workloads, including 4 KB random reads and writes, sequential reads and writes, and finally our server workloads. As you can see, each metric exhibits its own distinct power level. In general, sequential writes draw the most power, while reads draw the least.
In mixed workloads, you can visualize the read/write balance. For example, the database profile has the highest power consumption because it biases most heavily to writes, while the Web server test sit at the opposite end of the spectrum.
In this particular case, I only ran each test for 10 seconds to illustrate my point. On the next page, however, I'll get into the official results based on much longer durations.
Next, I investigated use of the TRIM command by first writing a 100 GB sequential file to the drive. You see the final few seconds of that at the start of my line graph. Once the write completes, I open up the Recycle Bin and delete the file, which causes a short impulse near the center of the chart. Finally, the TRIM command is seen actually executing.
The graph looks really simple, but there are quite a few observations we can make. As soon as the sequential write completes, the M500DC transitions back to active idle almost immediately. This shows that the SSD not only wrote the data as soon as it was received, but also kept up with its internal tasks (like wear leveling and garbage collection). On lower-performance SSDs, I've seen continued high power draw for as long as 10 seconds after the write supposedly finished. Also interesting, once the Recycle Bin is emptied, an additional 11 seconds pass before Micron's drive actually triggers the TRIM command. At that point, the M500DC only needs 2.3 seconds to execute it. On some drives, this can take 10 to 20 seconds to finish, making Micron's offering one of the quickest I've ever seen.
If you've read my previous enterprise-oriented drive reviews, you're already familiar with my Enterprise Video testing, where I look at large block sequential writes across each SSD's entire span. I then evaluate the drive based on the frequency and severity of its performance dips. Almost every SSD demonstrates some sort of unique, periodic pattern normally attributed to its background tasks.
When I started running our power testing, I noticed the same patterns. The graph above shows our typical Enterprise Video test, but instead of just recording timestamps after each block was written, I also measured power. And every single dip in performance matches up with dips in power use. More interesting, both dips (performance and power) are of the same general magnitude. In this case, the background tasks causing the dips stress the drive less than the actual workload being applied.
Finally, when it comes to talking about mobile-oriented SSDs, power consumption is almost always related to a drive's ability to enter idle and sleep states. This is due to the fact that utilization of consumer drives is typically low, and sleep states can add precious minutes to battery life. Enterprise customers have a completely different set of requirements and expectations. Their applications typically have a very high duty cycle, and therefore do not spend much of their lives sleeping. In many cases, low-power states can even be detrimental to enterprise applications, since going in and out of them takes time, and small delays are potentially costly.
In our testing, when we talk about idle power, we are referring to Active Idle. SSDs enter idle and sleep states either through Host-Initiated Power Management (HIPM) or Device-Initiated Power Management (DIPM). Measuring DIPM-enabled SSDs, it can be difficult (going only on power consumption) to determine the state a drive is in. This is especially true for Partial Idle, because time-to-active is less than 10 microseconds.
Results: Power ConsumptionWith a firm understanding of how our power testing works, let's check out the results. First up is Active Idle.
We're adding Samsung's 843 to the chart, since it's based on the notoriously frugal 840 Pro. Micron's M500DC hovers around 1 W through most of our measurement. That's roughly 50% higher than the two Intel drives and almost three times higher than the 843. There are IT professionals out there who like using enterprise storage in laptops and portable workstations. Due to its lack of DIPM and relatively high idle power, the M500DC would not be an ideal SSD for those on battery power, though.
A look at the power consumption from our sequential and random workloads shows the M500DC in the middle to high-end of the field. Unfortunately, the discipline where the M500DC excels, random write performance, is also where it draws a lot of power. Excluding the P400m, Micron's M500DC is over 1 W higher than the other SSDs in that test.
Once again, the M500DC is in the middle of the field. Granted, the SSDs we're testing include several different capacities, and fewer components in a drive mean less power consumption. So, it'd make sense that the M500DC and SSD DC S3700 are near the bottom. In an ideal world, all SSDs would be sampled in identical capacities to make comparisons easier. But that's just not the case.
Don't overlook the fact that Micron rates its M500DC at 6.2 W, and we were unable to push it past 5 W in any of our tests.
Creating A new Mid-Range Enterprise MarketOver the last year, the enterprise-oriented offerings from Micron have been a mixed bag. While we really liked its PCIe-based accelerators, the P400m couldn't quite stand up to its competition. That was especially disappointing considering the company's expansive NAND portfolio and firmware expertise. Christopher and I have always said that SSD vendors with NAND production capabilities should always come out on top. With the M500DC, Micron lives up to that expectation with a product that offers good performance at what we expect will be attractive pricing.
When it comes to comparing SSDs, you already know that there are many variables to consider: price, performance, endurance, value-adds, and more. Micron's M500DC should make you think a little harder about each if you're in the position to outfit a big organization with solid-state storage. It doesn't fit into some of the more traditional markets carved out in recent months. Outside of SanDisk's Optimus line, there simply aren't many drives that match its specs. And the M500DC doesn't lead in many categories, either. But where it does shine, it bests an impressive list of relatively comparable products.
Let's start with the bad. In straight read performance, Micron trails the pack. Demonstrating lower sequential and random read throughput, the M500DC is not suited for read-heavy applications. Instead, you'd be better off tapping Micron's M500 or Intel's SSD DC S3500.
Write performance favors the M500DC more, and it gives pricier SSDs a run for their money. Even though the 800 GB model's specs trail the 480 and 240 GB versions, the drive we're reviewing still outclasses most entry-level enterprise-oriented SSDs.
Enterprise workloads, so long as they involve writes, show Micron's latest excelling. The M500DC posts incredibly high numbers, particularly in our test designed to replicate the behavior of a database.
Write endurance has the M500DC in the middle of a distinguished pack. It's much better than the read-focused entry-level drives, but naturally trails the eMLC- and SLC-based offerings. Further, endurance is a tricky spec to evaluate. It used to be that endurance was closely related to the type of NAND used. But Micron (and SanDisk) extends the life of its flash well beyond the stuff most consumers encounter. They're consequently able to offer better $/TBW, which is what consumers are, presumably, asking for.
So, it all comes back to what enterprise customers want in an SSD. Micron believes it knows, and it tailors the M500DC's performance to match. For mixed-workload environments, the product of those efforts performs as well as anything on the market. And for where we expect its price to land, the M500DC should end up in a class by itself.
source:tomshardware
