2400 cas10 are Timings MFR can do, but GSkill used Samsungs on these from the start - there are lots of reviews that prove this as well as tests - as the 2400cas10 were released long time ago, when MFR was not popular, and lots of cfr failed these specs, Samsung were used, and are used today, single and dual sided Samsung. On the 2400 cas9 I agree, because Samsung D are eol, these are getting down in availability as well.