Is A SATA 3Gb/s Platform Still Worth Upgrading With An SSD?

Today's fastest SSDs already bounce off the SATA 6Gb/s interface's throughput ceiling. Does a 3 Gb/s link kill the performance of those drives? We run a number of synthetic and real-world tests to assess the damage when you upgrade an older platform.

There are many ways to tune up a PC. But usually, the only way to extract big performance gains is to start replacing hardware. Overclocking remains popular. However, it was arguably a more effective way of milking gains from CPUs, GPUs, and memory back in the day. Take a Celeron 300A, get it to 450 MHz, and you have a 50%-higher frequency. It'd take a 5.25 GHz overclock to get the same boost from a Core i7-3770K. And even then, there's no guarantee that the desktop applications you run would scale as well. 

We've burned enough components to know that overclocking has its risks, too (that's why Thomas sticks to processor voltages of 1.35 V or less in his 7-series chipset-based motherboard round-ups). Tweaking around with reference clock rates, multipliers, voltages, and latencies can hammer your system's stability in a hurry.

Once you're happy with your processor and motherboard, swapping in a new graphics card, doubling your RAM on the cheap, and adding an SSD are all great ways to balance performance and keep your machine running optimally. Today, we're focusing on solid-state storage, which dips down under £0.75/GB in many cases, making it more economically feasible now than ever before. We've said it before and we'll say it again: if you don't have an SSD yet, get one. It'll alter your perception of responsiveness.

Modern SSDs slam right up against the SATA 6Gb/s interface's throughput ceiling, while mechanical hard disks aren't much faster than they were five years ago. Perhaps more important than the 550 MB/s many solid-state drives achieve in sequential data transfers, however, is their ability to handle random I/O deftly in the real world. An SSD can usually field orders of magnitude more requests per second than conventional media (tens of thousands versus a couple hundred).

We can rip off speeds and feeds all day. The point is that we've run the numbers; we know an SSD is a worthwhile upgrade for anyone with a hard drive in their PC still. Windows boots faster, apps launch quicker, and files end up where you need them sooner. 

But Is An Old SATA 3Gb/s Port Enough For A Modern SATA 6Gb/s SSD?

We ask this question every time we run out of ports on our mainstream Intel-based platforms, which only offer two 6 Gb/s SATA ports (Ed.: In fact, I'm currently capturing video on a four-drive array of Crucial m4s connected to 3 Gb/s ports). And what if you have an older machine limited to the previous-gen standard? Is the upgrade still worthwhile? Given that we've already seen the fastest SSDs capped by 6 Gb/s SATA, it's safe to bet that a 3 Gb/s port is going to limit performance. But how much? Does it make a palpable difference, or is it only something you'd see in benchmark results? Should you upgrade your storage controller, too?

In search of answers, we took Samsung's 840 Pro, hooked it up to a 6 Gb/s port, and then attached it to a previous-gen interface. While the Samsung drive is one of the fastest out there, consider these results representative of most high-end SSDs. Note also that we left out SATA 1.5Gb/s. It would have been nice to include for the sake of a third data point; however, that takes us all the way back to 2005 or thereabouts. If your PC is eight years old, it's time for a new one.

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  • Meanbob
    Thank you for performing these tests. This information is very helpful.
  • Douglas Miller
    There are some great deals floating around for last years SSDs as well as Sata II SSD's. Firmware updates have cleared many problems with old controllers so if you need to perk up an old PC and have a few extra bucks, I say have at it.
  • C12Friedman
    This was a great article IMO, I really appreciate that a WD Velociraptor was used as the 'standard' for hard drives. I've been 'pushing' SSD's since I put one in my rig over a year ago - seems this article (and others like it) simply hammers home that message
  • das_stig
    Well what a shocking conclusion DOH!, of course it still makes sense to have an SSD hooked up to SATA2/3 over a HDD. When we get 1TB+ SSD's at the same price point as HDD's then HDD manufacturing will slow down and the price will go up for those still needing clunkers !