RAM what does PC mean for it?

[ESPplayer7]

what does it mean when ram is pc 2300 (dunno #'s) but is higher better, can only put ram with the same pc # together on a mo?

[ESPplayer7]

also, when u put a new stick of ram in do you need to configure bios at all on boot up?

[ESPplayer7]

anyone out there with an answer?

[jlreich]

Yes, higher is better. It indicates the speed of the ram. pc3200 =DDR400MHz, pc2700 =DDR333MHz, and so on. You will usually not need to mess with the bios when you put new ram in.

Just make sure you have the right type of ram for your system. 184 pin or 168 pin.

If you go to http://www.crucial.com/ and use their memory selector, it will tell you what you need for your system.

Usually it is no problem to use a higher speed ram than what your mobo says. If you system has pc2100, you can have pc3200 with no problem.

[saphalline]

Usually it is no problem to use a higher speed ram than what your mobo says.
Except if you don't have DDR RAM in your computer. Only DDR so far has remained completely backwards compatible from beginning to end. The older ones, like SDRAM and EDO and FPM and the original DRAM DIP chips, all had limitations in compatibility. Mostly related to density, speed, and parity/ECC. Mixing speeds on these older types of RAM is not recommended unless you check it out first.

For DDR, here's what those "PC" numbers mean:

PC1600 = DDR200 = 200MHz DDR RAM
PC2100 = DDR266 = 266MHz DDR RAM
PC2700 = DDR333 = 333MHz DDR RAM
PC3200 = DDR400 = 400MHz DDR RAM

There are also a few non-JEDEC standard ones out there. These are basically overclocked versions of the above.

PC2400 = DDR300
PC3000 = DDR375
PC3500 = DDR433~440 (depending)
PC4000 = DDR500
PC4200/4300 = DDR533

Moving into DDR2 land, the "PC" monikers have changed only slightly, just enough to show the difference:

PC2-3200 = DDR2-400 = 400MHz DDR2 RAM
PC2-4200 = DDR2-533 = 533MHz DDR2 RAM

More DDR2 memory will be coming in the future. The interesting thing about DDR2 is the way it scales up to improve RAM bandwidth. Instead of using the expected next-step of quad-pumping the RAM chips (known as QDR which actually died away), DDR2 really does what its name implies. It's double, double data rate. The RAM chips' speed is one-fourth of its rated speed, but instead of quad-pumping the bus, the bus is doubled, then doubled again, by a method prefetching two bits per clock edge instead of one like DDR. It makes for an interesting ride on the latency rollercoaster, but all in all, it was much easier to do this than pure QDR.

[Quantax]

Except if you don't have DDR RAM in your computer. Only DDR so far has remained completely backwards compatible from beginning to end. The older ones, like SDRAM and EDO and FPM and the original DRAM DIP chips, all had limitations in compatibility. Mostly related to density, speed, and parity/ECC. Mixing speeds on these older types of RAM is not recommended unless you check it out first.


.
Which I discovered(the incompatiblity that is)when mixing older and newer SDRAM chips whose speed matched(PC133)but which didn't work most likely from the other reasons you've cited but which I didn't know about until reading about it later.