今天的問答環節由SuperUser提供，這是Stack Exchange的一個細分，Stack Exchange是一個社區驅動的問答網站分組。
照片由Hong Chang Bum（Flickr）提供。
I was reading this article on testing SSDs from Tom’s Hardware and came across the following claim:
- With SSDs, performance varies by capacity point. Smaller drives tend to be slower than larger ones, even in the same family.
However, the article does not back up the claim or explain why. It does not seem intuitive to me that smaller SSD drives would be slower. I would expect it to be the other way around since a larger drive has a wider “area” to access via the same bandwidth. In researching SSDs, I have found that many sites do not even include SSD drives smaller than 240 GB in their comparisons.
So, is it true that smaller (capacity) SSDs are slower? If so, why is that the case?
Larger SSDs are faster because they use more Channels in parallel while smaller ones only use a few channels (4 instead of 8):
The higher capacity variants of an SSD model often get their higher capacity from simply having more NAND flash chips of the same type as the lower capacity variants. Having more NAND flash chips allows for a design where the controller on the SSD can access more data in parallel, allowing for higher speeds.