Plextor M6S series review: Slow performance for the price

When compared with any consumer-grade hard drive, the Plextor M6S solid-state drive (SSD) is energy-efficient, not to mention much faster. When you stack it up against other SSDs, however, its slower performance just doesn't measure up.

6.8

Plextor M6S series

The Good

The <b>Plextor M6S</b> has low power consumption and is a great performance upgrade for a computer that still runs on a regular hard drive.

The Bad

Compared with other solid-state drives on the market, the M6S' performance is disappointing. It also comes with only a short three-year warranty.

The Bottom Line

With unimpressive performance that doesn't match its high price, there's no reason why you should pick the Plextor M6S over other SSDs on the market.

Available in three capacities -- 128GB, 258GB, and 512GB, with the suggested retail prices of $140, $250, and $500, respectively -- the new M6S is the first I've seen from Plextor that costs less than $1 per gigabyte at launch. That's a welcome change from the company, but they're still much more expensive than competing devices.

If the Plextor sold the M6S's three versions at around $70, $150, and $300, then I'd recommend them. But at their current prices, they don't deliver performance you should expect. That makes them far from the best choices on the market. Until their price goes down significantly, choose something from this list, instead.

Design and features

The new M6S series shares the same dimensions as previous SSDs from Plextor, the M5 series . It's a standard 2.5-inch internal drive that use the now-common 7mm thickness. This means the drive can be used in all desktops, as well as standard laptops and certain ultrabooks.

On the inside, the M6S is actually a step down from the previous M5 Pro. The new drive uses Marvell's 88SS9188 controller, which has only four channels, compared to the eight-channel controller used in the previous generation. This generally means lower cost and less power consumption, but also slower performance.

That said, with the release of the M6S, it's the first time Plextor has dipped its toes into the budget market of solid-state drives. With the M5 Pro and M5 Pro Xtreme, the company intended to aim for the top end of the market in terms of both performance and cost.

The M6S comes with a modest mean time between failures (MTBF) of 1.5 millions hours (this is compared with 2 millions hours for others) and a relatively short warranty of three years (as opposed to the five-year plans that come with many high-end drives.) MTBF basically means the average elapsed time before the drive might fail. There's no support for hardware encryption, either, which is not a big deal for home users, but for business users, it means they can't keep their data safe in case of theft.

The M6S comes with very high endurance, which is measured in program/erase (P/E) cycles. You can write some 65GB of data to it each and every day for three years before it's likely to become unreliable. Most of us don't write that much per day at all, and definitely not every day. (Read more about endurance here.) That said, it's safe to say that you'll find other reasons to replace the drive before it runs out of P/E cycles.

Cost per gigabyte

Apart from the 128GB capacity, the M6S is priced well below $1 per gigabyte at launch. For a budget drive, this pricing is actually very high, but for Plextor, it's quite good. The company has always been over the top when it comes to its SSDs' prices, and the M6S is its most affordable SSD so far.

Since the actual price of SSDs is always lower than the suggested price, it's very likely that the street price of the M6S will be even lower. And it needs to be quite a bit lower to be competitive. The Samsung 840 Evo, for example, costs close to just 50 cents per gigabyte; it's also much faster and offers up to 1TB of storage space.

Performance
Equipped with the stripped-down version of the controller, it's expected that the M6S' performance won't impress and that was how it panned out in my testing.

In data transferring test, the new drives registered the sustained sequential write speed of just 145MBps, the second slowest I've seen among recently reviewed SSDs. It did better with the read test, scoring 228MBps, about the average on the charts. When performing both read and write tests at the same time, the M6S now showed 155MBps, again the second slowest on the chart.

I also tested the drive with PC Mark 8, which benchmarks the entire system. The M6S received its best score on the Storage test with a score of 4,810. Still this is the second-lowest among recent SSDs. For the Home and Work benchmark, which is geared toward measuring the performance for home and work applications, respectively, it registered just 3,289 and 3,116, respectively, among the lowest I've seen among SSDs.

Note that this is all very relative because if you upgrade to this drive from a hard drive, you will still see a world of difference in terms of overall performance. The computer will have its boot time cut down greatly and applications will launch much faster. The numbers shown here are only relevant when comparing the M6S to other SSDs.

Plextor says the new drive has very low power consumption. I tried it anecdotally with a laptop and did see some increase in battery life. The difference, while not much -- about 10 minutes of extra battery life -- was enough to say that the drive indeed used much less power than a regular hard drive.

Conclusion

If you actually buy the Plextor, you won't be disappointed with its performance as a replacement drive. But there's no clear reason why you should buy it in the first place, unless the company lowers its sale price by at least 40 percent. For now, you can find much better deals on the market, such as the Samusng 840 Evo or the Seagate 600 SSD , that are not only faster but also a lot more affordable.