For PC Storage, Look Beyond a ‘Bit’ of Marketing

An Industry In Sync

In the PC storage industry, much has been made of the different media technologies underlying today’s most popular products. While most newer systems have migrated from mechanical hard disk drives (HDDs) to solid-state drives (SSDs) for their inherent performance benefits, a debate remains about which particular solid-state technology offers the best balance between price and user experience.

In particular, the notion of “bits per cell” – that is, how many pieces of information each individual solid-state cell can store – has been a subject of heated back-and-forth marketing among SSD vendors in recent years. The earliest SSDs, circa 2008, used single-level cells (SLC), capable of storing one bit of data each. These offered extremely high performance and endurance, but at a cost that put such drives out of reach of mainstream consumers.

Later innovations increased the density of solid-state storage – first MLC (two bits per cell), followed later by TLC (three) and QLC (four). Each time, the storage devices they were built on became more affordable and offered higher capacities but traded off some amount of performance and endurance.?(The physical reasons for these tradeoffs are for another article – it’s enough for now to understand they exist.)

Over time, manufacturers developed technology breakthroughs that enabled high-level performance and endurance even as storage density increased. Today, nearly all SSDs in personal computers use either TLC or QLC media – these have been identified as best serving the market “sweet spot” when paired with clever features to mitigate the tradeoffs.

The Divergence

Here’s where opinions diverge, depending on which SSD vendor you’re talking to. It’s generally accepted that TLC devices best fit the high end PC market and QLC offer a better price/performance mix for the low end, but what’s the right choice for everyone in the middle? Is an SSD built on QLC good enough for mainstream usage?

What’s our take? ?Sure, maybe. Or maybe not. Let us explain.

We certainly believe our QLC products are up to muster. In fact, we have put our Solidigm 670p (formerly Intel? SSD 670p) up against competitors’ drives, including some using TLC, with very favorable results. (Check out the new white paper here.)

But we also believe that for SSD shoppers, the media question is the wrong place to start. After all, if our QLC drive can outperform other popular TLC drives in real-world tests, is that really the most useful distinction to make? Deciding primarily on the basis of “bits per cell” is like buying a car based on a single factor such as its chassis and overlooking all other design decisions.

Choosing an SSD primarily on the basis of “bits per cell” is like buying a car based on a single factor such as its chassis and overlooking all other design decisions.

At Solidigm, “bits per cell” is just one design choice among hundreds we make to ensure precise product-usage fit – others include host interface, NAND die size and quantity, controller channels, caching algorithms, power management policies, and so forth. The final product is the culmination of our careful attention to all these factors, ensuring we can offer a competitively priced solution with the best possible experience for the intended end-user.

We take great pains to ensure a first-class user experience on all our products by prioritizing performance where it matters most – in real-world workloads (nerd speak: predominantly random read-driven at low queue depth). While others might get a lot of mileage out of marketing their products on a “bits per cell” basis, we encourage savvy shoppers to look beyond that.

While others might get a lot of mileage out of marketing their products on a “bits per cell” basis, we encourage savvy shoppers to look beyond that.

As the wise chef once said, “the proof of the pudding is in the eating.” Much better to rely on measured performance in real-world workloads: the best route obviously being to compare the options oneself, but results are also often readily available from third parties in the form of product reviews or testimonials.

Armed with more than just a “bit” of information about how different solutions fare in the real world, PC users will be better prepared to make the right choice on storage.