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A look at SSD performance in Windows Vista

The more things change...
— 7:28 PM on July 1, 2009

We last published an SSD round-up a month and a half ago, squaring off a six-pack of new drives against Intel's well-established X25-M. In the end, we recommended the Intel drive, due to its all-around performance leadership, along with the homegrown and Corsair-branded versions of Samsung's PB22-J, on the strength of that design's solid performance, low cost per gigabyte, and modest power consumption. We weren't particular fans of the Super Talent and OCZ SSDs based on Indilinx's "Barefoot" SSD controller, though. The drives didn't fare well overall, and they were painfully slow in our real-world file creation and copy tests.

Those conclusions ruffled the feathers of more than a few forum fanboys, who sprung into action to defend the upstart Indilinx controller—and, more importantly I suspect, the honor of the Vertex SSDs inside their very own systems. Insults were hurled, flames raged, and through all the noise, a few relevant concerns emerged. Exploring them has largely monopolized my benchmarking time since.

First, we started with the easy stuff: the Vertex's firmware was updated, various drivers were freshened, and our test system's operating system was brought up to date with the latest patches. But the Vertex's performance didn't improve. Curious to see whether our decision to test drives in a "used" state could shed some light on the issue, we next probed differences in fresh versus used performance with the Indilinx, Intel, and Samsung drives. The Indilinx controller proved plenty quick when the drive was in its factory-fresh state with plenty of empty flash pages available for writing, but its performance dropped by a much greater margin than the Intel and Samsung drives when tested in a used state. It looked like we'd found our culprit.

All this testing was still being conducted on an older system that, while fast enough to stress even an X25-E Extreme, wasn't representative of the latest and greatest hardware. The system's Windows XP operating system was perhaps the greatest concern, because its default 63-sector partition offset starts the first partition in the middle of an SSD flash page rather than at the beginning of one. This misalignment apparently creates problems for the Indilinx controller, although it's not an issue for all SSDs. Intel says the X25-M isn't picky about such offsets, for example.

Still, since Windows Vista drops XP's default partition offset, we decided to test with it next. We updated our test system's hardware, as well, combining a Core 2 processor with 4GB of memory and Intel's most recent ICH10R south bridge SATA controller. But does this drastic overhaul change the SSD performance picture any? We've subjected drives based on controllers from Indilinx, Intel, and Samsung to a battery of tests in an attempt to find out.

And then there were three
We've narrowed our focus to three drives today because the results of our last SSD round-up nicely illustrated the fact that storage controllers (and firmware revisions) largely define SSD performance. Only a handful of different storage controllers are available, with numerous drives based on each. Intel's X25-M, for example, is available not only directly from the chip giant, but also through partner Kingston. Samsung makes its own drives, too, and its latest controller can be found in new models from Corsair and OCZ. Indilinx's SSD silicon may be the most promiscuous of the bunch. The company doesn't sell its own drives, but it has numerous partners, including OCZ, Super Talent, and Patriot, just to name a few.

Today, we'll be focusing our attention on the Intel X25-M, an OCZ Summit based on Samsung's latest controller, and the Indilinx-based OCZ Vertex. The performance of each drive should be representative of competing models and otherwise re-badged versions of the same underlying designs. However, we should note that SSD performance is somewhat dependant on overall drive capacity. A 30GB Indilinx-based design won't necessarily be as quick as a 120GB one. Keep that in mind if you're looking to save a little cash on a low-capacity unit.

Capacity Cache Controller Max reads Max writes Warranty Street price
Intel X25-M 80GB 16MB Intel PC29AS21AA0 250MB/s 70MB/s 3 years
OCZ Summit 120GB 128MB Samsung S3C29RBB01-YK40 220MB/s 200MB/s 3 years $369.99
OCZ Vertex 120GB 64MB Indilinx IDX110M00-LC 250MB/s 180MB/s 3 years

The X25-M has been around longer than its direct competition, and it shows on the spec sheet. With only 16MB of cache, the drive has substantially less RAM onboard than either the Indilinx or Samsung designs, which pack 64 and 128MB, respectively. The X25-M's write speed rating is quite a bit lower than the other drives, as well, despite the fact that all three drives use the same kind of multi-level cell (MLC) flash memory common in consumer-grade SSDs. Interestingly, Intel only clams a write speed of 170MB/s for the X25-E Extreme, which is based on pricier single-level cell (SLC) flash memory. Perhaps Intel is simply more conservative with performance ratings than its competition.

Of course, it's important not to put too much stock into these theoretical peak ratings. We have a full suite of tests that will more clearly illustrate how these drives perform in the real world. Before getting into those results, however, I should note one important difference between these three SSD designs. While drives based on the Indilinx and Intel controllers can have their firmware upgraded by end users, SSDs based on Samsung silicon cannot. It's unclear whether this is a hardware limitation specific to the Samsung design or whether the company simply prefers not to let users flash their own drives.

Support for user firmware flashing might not seem like an important consideration for a storage product. After all, apart from the last batch of broken Barracudas, I can't remember the last time a mechanical hard drive maker even issued a public firmware update. New firmware releases aren't uncommon in solid-state disks, though. We've already seen new firmware revisions dramatically improve the performance of some drives, and a few updates have also added new features. Enthusiasts won't want to miss out on either.

Samsung's lack of support for user firmware updates probably won't bother users of Samsung-branded drives, which only seem to be available in pre-built systems from the likes of Dell and HP. However, PC enthusiasts buying versions of the drive sold by the likes of Corsair and OCZ will surely want to be able to flash their drives. What's more, there's currently no way for those shopping on sites like Newegg to determine which firmware revision a given drive is running. Samsung really needs to change its policy on firmware updates, if not for its own drive models, then at least for those of its partners.