I recently installed a Kingston HyperX 3K 120GB SSD on Windows 7 x64. The install went smoothly, and everything seems to be working well. This SSD has only one partition, and that partition is properly aligned (starting offset = 1,048,576 bytes.)
I was under the impression that SSDs have 4,096 bytes/sector. Because of that I was surprised to see - in Windows 7 System Information - that my SSD has 512 bytes/sector. Am I misunderstanding something?
Well, after a lot of Google-ing I believe I have my answer.
SSDs are, in fact, configured with 4K (4,096 byte) sectors. However, a lot of hardware and software currently in use still presume that hard drives use a 512 byte sector. In order to maintain compatibility with legacy components, SSD firmware can emulate 512 byte sectors. This means that, to legacy hardware and software, the SSD appears to have 512 byte sectors.
In use, the translation between 4K and 512 byte sectors is transparent to the hardware and software accessing the hard disk drive and typically occurs with little or no degradation in performance. However, the translation is more complicated when partitions are not aligned to a 4K boundary, and in this case there will be a degradation in performance.
Therefore, what really matters for an SSD is that partitions are correctly aligned, and Windows 7 does this. If a SSD 'appears' to have 512 byte sectors that's just smoke and mirrors by the firmware: Internally, SSDs have 4K sectors.
It's not that complicated, really. The reason I had to do so much Google-ing is that when people ask this question, they are typically met with sarcastic replies, as if any idiot knows the answer. Tom's Forums are refreshingly free of this kind of attitude.