Micron 6500 ION 30.72TB SSD Review - The Density Advantage

Introduction and Drive Details

"It's all about the flash" is a catchall phrase that we at TweakTown love to trumpet whenever the opportunity arises. Well, the subject of today's review has us reaching for that trumpet once again. Micron's newest enterprise offering is the world's first 200+ layer datacenter NVMe SSD.

Now typically, and as it relates to that statement we like to trumpet, it's because a new flash-node is bringing with it a new level of performance. To be sure, this is very much the case with Micron's newly minted 232-Layer B58R flash that arrays our test subject. Micron 232-Layer flash has already proven to be the highest-performing flash we've come across to date, but new levels of performance are not what the Micron 6500 ION is targeted at.

Micron's 6500 ION is not tuned for raising the performance bar; that will be the job of other forthcoming Micron offerings arrayed with 232-Layer flash. The 6500 ION is all about raising the bar as it relates to TCO (Total Cost of Ownership (TCO) is the purchase price of an asset plus the costs of operation). TCO is the real bottom line in any datacenter environment.

TCO in the data center is measured across many data points, including upfront purchase costs, IOPS per watt, density (footprint), and lifespan (endurance) of the product. Recently, we've been seeing QLC arrayed SSDs making their way into datacenters as a means of lowering TCO. However, QLC only lowers TCO in two ways - upfront costs and rack density - with rack density not being an absolute win for QLC, as at this point, there are some TLC SSDs that can offer the same rack density as QLC.

So basically, at least so far, QLC SSDs in the datacenter are being implemented as a means of lowering upfront capital expenditure for limited roles such as read only and cool storage where write endurance is far less of a consideration than typical mixed-use scenarios. Enter Micron's 6500 ION 30.72TB TLC arrayed SSD, designed to redefine affordable, scalable NVMe storage in an era where IT budgets can't keep up with exponential data growth.

Micron has uniquely positioned its 232-Layer TLC arrayed 6500 ION 30.72TB to compete against QLC solutions by offering its superior in every way 6500 ION for a similar price per gigabyte of storage. TLC for the price of QLC? How is this even possible? Turns out more layers is the key. The density enabled by 232-Layers enables Micron to offer its TLC flash for a similar price per gigabyte to that of current 144-Layer QLC flash. Incredible.

As everyone knows, TLC is fundamentally superior to QLC; there are rare exceptions based on competing architectures, but those, at least to this point, are all manifested in the consumer space. Bit for bit, TLC is vastly more endurant than QLC, more power efficient than QLC, and typically offers vastly superior performance than QLC.

Micron offers up the following comparison to illustrate why its 6500 ION offers a far better value proposition than that of current QLC datacenter SSDs:

The Micron 6500 ION SSD offers better overall performance, endurance, read quality of service (QoS), drive fill, and real workload performance than the leading competitor's capacity-focused QLC SSDs. Additionally, TLC is inherently more power efficient than QLC and offers superior data retention over time. Simply better in every way.

As we view it, if TLC can be had for QLC pricing or somewhere even close to QLC pricing, that niche recently carved out by high-density datacenter QLC SSDs could be in serious jeopardy.

Okay. Let's see what Micron's newest datacenter offering can do for you by the numbers.

Specs/Comparison Products

Interestingly, Micron's 6500 ION is offered in one capacity only, 30.72TB. This again speaks to Micron positioning the 6500 ION as a superior alternative to high-density QLC datacenter SSDs.

Micron 6500 ION 30.72TB NVMe PCIe Gen4 x4 U.3 SSD

Enterprise Testing Methodology

TweakTown strictly adheres to industry-accepted Enterprise Solid State Storage testing procedures. Each test we perform repeats the same sequence of the following four steps:

1. Secure Erase SSD
2. Write the entire capacity of SSD a minimum of 2x with 128KB sequential write data, seamlessly transition to the next step
3. Precondition SSD at maximum QD measured (QD32 for SATA, QD256 for PCIe) with the test-specific workload for a sufficient amount of time to reach a constant steady-state, seamlessly transition to the next step
4. Run test-specific workload for 5-minutes at each measured Queue Depth, and record results

Benchmarks - Random and Sequential

4K Random Write/Read

We precondition the drive for 64,000 seconds, receiving performance data every 4 seconds. We plot this data to observe the test subject's descent into steady-state and to verify steady-state is in effect as we seamlessly transition into testing at queue depth. Steady-state is achieved at 24,000 seconds of preconditioning. The average steady-state write performance at QD256 is approximately 260K IOPS. The tight pattern with virtually no outliers indicates high QoS.

Micron told us that the 6500 ION should perform about the same as its 7450 Pro, which is pretty much what we are seeing here. Although at QD16, the 6500 ION is dishing up 10% more performance than the B47R arrayed 7450 Pro. Micron also indicated that its 6500 ION is conservatively spec'd, especially as it relates to write performance. This is exactly what we are seeing as we are getting 75K more IOPS here than the drive is spec'd for.

Here we find our test subject not only outperforming the 7450 Pro across the board but even outperforming the 9400 Pro 30.72TB at queue depths of up to 64. This is super impressive and to our way of seeing things, indicates to us that the 6500 ION has been tuned down to not infringe on Micron's high-performance class of SSDs, such as the 9400 Pro, as well as future 232-Layer arrayed high-performance offerings.

8K Random Write/Read

We precondition the drive for 64,000 seconds, receiving performance data every 4 seconds. We plot this data to observe the test subject's descent into steady-state and to verify steady-state is in effect as we seamlessly transition into testing at queue depth. Steady-state is achieved at 52,000 seconds of preconditioning. The average steady-state write performance at QD256 is approximately 127K IOPS.

We expect 8K random to track exactly the same as 4K random, just at a lower rate because it's moving twice the amount of data. The 6500 ION delivers as expected in terms of overall throughput and is better than expected at queue depths of up to 4. Impressive.

At QD1-2, the 7450 Pro has the edge, but the rest of the way up to QD256, the 6500 ION delivers more.

128K Sequential Write/Read

We precondition the drive for 26,000 seconds, receiving performance data every 4 seconds. Steady-state for this test kicks in at 0 seconds. The average steady-state sequential write performance at QD256 is approximately 5,900 MB/s. The tight pattern with virtually no outliers indicates high QoS.

Micron spec's the 6500 ION as capable of up to 5,000 MB/s sequential writes, but the drive can do a whole lot more as we are getting a whopping 5,900 MB/s at QD2 and higher. Impressive.

Micron spec's our test subject as capable of up to 6,800 MB/s 128K sequential read, which we find to be spot on as we were able to attain a high of 6,821 at QD64. The drive's performance curve is again almost a mirror image of the 7450 Pro, with the 7450 Pro having a small advantage at high queue depths. This has us wondering if the 6500 ION is controlled by the same controller as the 7450 Pro, just at a slightly lower clock speed.

Benchmarks - Workloads

4K 7030

4K 7030 is a commonly quoted workload performance metric for Enterprise SSDs.

We precondition the drive for 64,000 seconds, receiving performance data every 4 seconds. We plot this data to observe the test subject's descent into steady-state and to verify steady-state is in effect as we seamlessly transition into testing at queue depth. Steady-state is achieved at 40,000 seconds of preconditioning. The average steady-state write performance at QD256 is approximately 550K IOPS. The extremely tight pattern with virtually no outliers indicates high QoS.

Much higher-than-expected performance here. Micron spec's the 6500 ION as capable of up to 400K IOPS sustained, and we are hitting a whopping 552K IOPS at QD128. This is the second highest we've seen coming from a 1-DWPD class SSD. Only the 9400 Pro can deliver more. Outstanding. The most performance where it matters most, highlighting brilliantly the advantage TLC has over QLC.

Email Server

Our Email Server workload is a demanding 8K test with a 50 percent R/W distribution. This application gives a good indication of how well a drive will perform in a write-heavy workload environment.

We precondition the drive for 64,000 seconds, receiving performance data every 4 seconds. We plot this data to observe the test subject's descent into steady-state and to verify steady-state is in effect as we seamlessly transition into testing at queue depth. Steady-state is achieved at 40,000 seconds of preconditioning. The average steady-state write performance at QD256 is approximately 225K IOPS. The extremely tight pattern with virtually no outliers indicates high QoS.

At queue depths of 4 and higher, the 6500 ION transforms into a beast, again delivering the second-best we've seen to date for a 1-DWPD class SSD. A high of 241K is achieved at QD64 where the 6500 ION is, 9400 Pro aside, delivering a whopping 27% more than any 1-DWPD class SSD we've ever tested. Amazing.

OLTP/Database Server

Our On-Line Transaction Processing (OLTP) / Database workload is a demanding 8K test with a 66/33 percent R/W distribution. OLTP is online processing of financial transactions and high-frequency trading.

We precondition the drive for 64,000 seconds, receiving performance data every 4 seconds. We plot this data to observe the test subject's descent into steady-state and to verify steady-state is in effect as we seamlessly transition into testing at queue depth. Steady-state is achieved at 48,000 seconds of preconditioning. The average steady-state write performance at QD256 is approximately 275K IOPS. The extremely tight pattern with virtually no outliers beyond entering full steady-state indicates high QoS.

Again, and completely as expected based on the previous two tests, we find our test subject punching above its weight, delivering best-in-class performance at queue depths of 8 and higher. Impressive.

Web Server

Our Web Server workload is a pure random read test with a wide range of file sizes, ranging from 512B to 512KB at varying percentage rates per file size.

We precondition the drive for 64,000 seconds, receiving performance data every 4 seconds. We plot this data to observe the test subject's descent into steady-state and to verify steady-state is in effect as we seamlessly transition into testing at queue depth. We precondition for this test with an inverted (all-write) workload, so no relevant information can be gleaned from this preconditioning other than verification of steady-state.

Better than average performance here, which is more than expected considering what the 6500 ION is designed to do and further considering that this is the most taxing test we run.

Final Thoughts

When we first heard of this SSD, we figured it would be Micron's answer to Solidigm/Intel's QLC datacenter SSDs and would be arrayed with QLC. We got the first part right in that it is Micron's answer to QLC datacenter SSDs, but we were mind-blown that it's TLC and not QLC, as we surmised it would have to be. TLC for the price of QLC? We had no idea that could even be done, but Micron, with its density leadership, can do it and is doing it beginning two weeks from now on May 30th, 2023.

It's hard to imagine how competing QLC datacenter SSDs can weather this storage storm coming from Micron. The TLC arrayed 6500 ION is vastly superior in every way to its QLC competition. Naturally, the QLC competition will have to take a dramatic price drop to remain relevant, but we are not certain the QLC competition can go low enough to surpass the value proposition Micron's 6500 ION 30.72TB has on offer. Time will tell. Editor's Choice.