PC Memory... can someone explain the rating system?

[SamanthaStevens]

This is probably a real "DUH" question, but since I've been out of the loop and am trying to jump back in can someone explain the memory numbering system in use today?

Back in the "good old days", memory was pc66, then pc100, etc. denoting how fast a fsb the memory could be run on (or something like that). I'm now looking to upgrade and I see RDRAM and DDR ram saying PC600, PC800, PC1600, PC2100...I'm sure the fsb ain't going that fast, so what's the deal? If I wanted to buy an Athlon board (and either bought or planned on buying a 266mhz "C" Athlon), what's the advantage to PC2100 memory (besides the higher price)?

Thanks to any that can shed some light on the subject.

 

[Superdoopercooper]

In the case of RDRAM, the "name" is the speed. PC600 is 600MHz (not sure if this is a 300MHz DDR kinda thing, but 600MHz nonetheless), and PC800 is 800MHz.

In the case of DDR, PC2100 is DDR SDRAM DIMMs that can do the 266Mhz FSB (i.e. the Athlon "C" Core) and the PC1600 is the DDR that can do 200MHz FSB (all other Athlons & Durons). In many cases, people have been able to bumb their Athlons/Durons up to 266FSB just by using the L1 unlocking trick... see other posts in the CPU forum.

So, if you are getting the Athlon "C", I would recommend a motherboard that has KT-133A chipset. Then, you'll just want to buy some GOOD PC-133 Ram. This will do two things for you... it will still have the 266Mhz FSB becuase the KT133A chipset supports it, and it will be significantly cheaper than buying a DDR motherboard and DDR Ram, which only give you 5% or so of added performance, and in some cases not even that... depends on what you do. For games and stuff, the KT133A is the way to go.

Check out the AnandTech's (and others) reviews on the KT133A chipset, and which MB's they prefer.

Hope this sheds some light.

 

[Ozzman1113]

-Sam

pc2100 means 2.1g/s data rate. 1600 = 1.6 gigs a sec. they run at 133 and 100mhz respectively. with the 'double data rate' they double the fsb speeds and call it 266 and 200. the rdram runs at 300 and 400 mhz (meant for p4), but since they are all doubled they name it pc600 and pc800

the 2100 will just give you a larger fsb bandwidth.
im gonna be picking some of that up with an Athlon C and an Iwill KA266 board pretty soon. Yippie