About a week ago, I sent Dell an email asking which caddy was used by the Optiplex 990. They got back to me a day later, saying that it uses the DN8MY caddy. Unfortunately, that doesn't help me because Amazon has a bunch of caddies which are supposedly identical. I asked on a couple Amazon pages and one person said that the caddies aren't as standardized as they should be and that it's a "buy and try" kind of affair. I'd really like to avoid having to buy a ton of caddies. Has anyone found a caddy which is compatible with the Optiplex 990?