Will IDE/SATA adapter boost speeds?

If the ATA-100 and SATA drives are otherwise equivalent, there won't be any difference in performance, as you're limited by the mobo ATA-100 interface.

I think we're in violent agreement. Let's try this again, at some reduction in concision ...

If the ATA-100 and SATA drives are otherwise equivalent, there likely won't be any significant difference in the performance of the system, as the ATA-100 interface imposes a fundamental limitation. Even though SATA drives have a higher interface speed than ATA, that does not fundamentally get you anything, as the bottlneck is the mobo ATA-100 interface.

That said, an older ATA drive is likely *not* otherwise equivalent to a more modern SATA drive, e.g., larger caches and higher densities/xfer rates. Thus, a SATA drive might provide some performance benefit (even through an ATA interface), although whether you'd notice it is dubious given the system specs. (Don't lose any sleep or spend money over it.)

To take full advantage of a SATA drive (both higher interface speeds and capabilities such as NCQ), you'd want a SATA controller. You may be able to get a PCI SATA controller for not much more than the price of one of those IDE-SATA adapters (assuming you have a free PCI slot). If you can, then it might be worth it...

In short:

1. If you have an IDE ATA-100 drive that suits your needs, stick with it.

2. If you're going to get a new drive, then consider a SATA drive and controller if you can do it for close to the same price as the ATA drive. (Agree with Crashman on avoiding the dongle-type adapters.)

I'd suggest the primary decision criteria for (2), other than price obviously, is really less a matter of performance, and more a matter of what you want or expect to easily reuse in another system in the future. Another IDE drive? Doubtful. The PCI SATA controller? Very doubtful. A SATA drive? Very probably. (Of course that depends on what other systems/uses you might put those components to. Lots of ancient IDE drives still doing yeoman's work these days.)