Hi, let me first say I have seen the FAQ on this issue for older Windows versions - but am unsure if it applies to Win7.
I bought a 2TB Caviar Black as an upgrade, it's SATA2. I just installed Win7 on it, when I realized that my controller is a SATA1 card.
My system is getting on a bit, but I figured for what I do (programming) the HDD was my bottleneck. So I have the option of either getting a $50 SATA2 card, or living with the SATA1 or upgrading MB+CPU to 64bit, dual core etc.
1. For random access on smaller (say <1MB) files, is SATA2 going to give me any advantage over SATA1? Is SATA2 just better for very large files. I realize that it's 300MB/s bandwidth instead of 150.
2. If I just live with my SATA1 for a while and then upgrade, am I going to be able to switch the storage controller on Win7?
SATA1 speeds should be fine for a mechanical hard drive, at least for the ones made so far. The 2TB Caviar Black drive has a maximum sustained transfer rate of 138MB/sec - that's within SATA1 specs, and you'll almost never hit that rate anyway because it only applies to the outermost tracks and to the transfer of fairly large files.