Question about Corsair, Patriot, OCZ, etc.

I'm just a bit (and always have been) confused about the logistics behind this, and couldn't find anything through Google, so I'm just asking kinda "for my knowledge".

So Samsung, Hynix, etc all manufacture their own ram. Does Corsair and Patriot and OCZ manufacture their own RAM? Or do they get them from places like Samsung, Hynix, etc and just tweak them and add heat spreaders?

Just somethin' that's been bugging me for a while.

Most well known brands like Corsair, OCZ, PDP, Geil etc only make memory kits from chips delivered by producers like Samsung, Hynix, Winbond, Qimonda, Micron, Elpida, PSC, ... Some have their own brands like Micron has their Crucial series.
So it looks like you can get the same chips with the same overclocking potencial in different memory kits. Lately most popular chips in DDR3 are PSC and Elpida. So PSC you can find in most G.Skill, OCZ, A-Data, Mushkin and many more. When Elpida hypers were in mass production then you could find them in most expensive kits of all brands. Now most Elpidas are in cheaper kits with BBSE and other BBxx chips till about 2000. Still can get them mixed with hypers in Kingston T1, Corsair's highest Dominators etc.
Highest clock kits are now all on PSC what you can see checking Corsair 2500+ kits and for example Mushkin Ridgebacks so almost all kits from 1600-2533 can have the same chips with timings from 6-8-6 till 10-12-10. Best memory producers are checking best chips, matching all and are making kits that are rated higher than most other on market that only keep standard specification.

That's great info! Thanks alot! Exactly what I wanted to know

Understand however that just because RAM is tested to run at a high frequency does not mean that all the other hardware in your PC is capable of running the RAM at it's max speed. How well all of the hardware plays together combined with the CPU design determines how fast the RAM will run stable in any given PC. In addition with the greater bandwidth of new CPUs, you may see little tangible system performance change with just an increase in RAM operating frequency or lowering of RAM latency compared to years ago when data bandwidth was far more limited.

Yeah, I'm really asking more about the companies and their logistics more than the ram & its limitations in my system, but thanks for that info too.