Hardware upgrades can be a blast. Slide 2GB more RAM in your machine and everything just works faster and smoother. Updating a laptop or desktop with an SSD (solid-state drive), however, can be tricky and not so rewarding, as I am finding.

I haven't tested any enterprise-class SSDs yet, but I want to share some of my findings testing flash SSD devices on laptops and desktops. In short, your machines may not be able to keep up with the drives' speed, and unfortunately there is no easy way to tell beforehand what will happen with your specific system.

What I learned during my tests is that using devices capable of sustaining very fast throughput such as an SSD is a surefire way to reveal old or slow machines: With new SSDs in place, some of the desktops in my lab suddenly showed their disk access slowness.

I was expecting the immediate top-notch performance trumpeted by the drive vendors, but in many cases, performance was on a par with that of spinning drives, even in terms of throughput, where a flash SSD is supposed to win hands-down.

Was there something wrong with my test units? I checked in with the drive vendors, and the culprit was revealed: Some motherboard chip sets that control SATA connections seem to have their performance capped and, like automobiles with the hand brake on, weren't able to produce top speeds in my benchmarks.

The good news is that in many cases a simple driver update can improve performance dramatically. On some motherboards, I saw an improvement of 10MBps to 20MBps after installing the latest drivers. Unfortunately, not every motherboard can be brought up to speed, and I don't have enough variety in my lab to compile a comprehensive list of what can be made to work faster and what can't; so before trying an SSD upgrade, browse your motherboard vendor's Web site to download, or ensure you have, the latest drivers.

And this goes for those of you who use automatic updates. I had to download a new driver manually on some of my machines, because apparently the new drivers in question are not always captured by the automated update cycles. For example, after manually updating the Nvidia nForce driver on this HP Pavilion, the burst speed -- which was well below 100MBps before the update -- cranked up to 122MBps.

If you have motherboards with Intel chip sets, don't miss this resource page, where the vendor explains which chip sets can be made to work in AHCI (Advanced Host Controller Interface) mode. Easy to do from the BIOS setup screen, this essentially releases that hand brake, cranking up performance while enabling important SATA features, as explained on the Intel resource page. Thanks to Roger Bradford, product marketing engineer for chip set and graphics marketing, for pointing me in the right direction with the Intel chip set.

I should also mention that the desktop I updated with new drivers manually is a relatively new machine. With older models, you might not be as lucky finding an updated driver. In other words, even the fastest SSD money can buy will not bring all the expected benefits if your motherboard can't keep up.

On those older machines without an upgrade option, you might be able to solve the problem with an add-on SATA card. But the few cards I tried did not give me improved SSD speed. Again, I can't categorically say that no add-on card will bring any benefit, but it will probably cost you, and unless you can verify via your vendor (or another person's experience) that your model is fast enough to keep up with an SSD, you might find yourself out of money with nothing to show for it -- obviously not where you want to be after implementing an expensive update.

How expensive? Well, the bare minimum to hold an OS and a few applications, 32GB, will cost you US$900 or more per unit, retail, according to a search on Google. Brand and form factor, in addition to capacity, will also affect your price. Of course, we can't blame the SSD vendors for the update risk, but considering the money involved, that's not something that anyone can afford to jump on lightly.