Can anyone tell me what ddr memory to run with my cel 1.7 400 fsb processor. How do you calculate what memory to use with what processor? Does it depend on the motherboad ? Any replies would be very much appreciated. Thanx
Depends on which chipset the motherboard uses. Memory speeds explained: PC1600=200MHz DDR PC2100=266MHz DDR PC2700=333MHz DDR PC3000=350MHz DDR PC3200=400MHz DDR PC3500=433MHz DDR The Celeron/P4 line works out as follows: 4x (system bus)=FSB 4x 100=400 4x 133=533 4x 200=800 Although you should be able to get away with PC1600, if you upgrade to a newer P4 with a 533MHz or 800MHz FSB, you'll either cap your bandwith or be unable to use the PC1600. Anymore, PC2100 is the slowest you'll find, but PC2700 isn't that much more expensive. The faster RAM will work fine at slower speeds, so you could go buy PC3500, and have no problems. It would be paying much more than necessary for extra RAM. I'd take into account your current motherboard's capabilities, if you plan to upgrade to a newer P4, and if that P4 upgrade would require the purchase of a motherboard to go with it. This is a general guide. We can help narrow down what's best if you can give a little more info about your system, such as the motherboard (or chipset----check device manager). Also, how much RAM you have now and what OS you're running.
The system bus is the speed which affects the RAM, and CPU FSB. DDR operates equivalent to 2x the speed of SDR SDRAM. PC1600 is equivalent to 200MHz SDR, but most people just have an easier time thinking of it as 200MHz RAM. With the Pentium 4 (and Celeron's 1.7GHz and up), Intel started to "quad-pump" the FSB, thus giving the FSB a boost. However, the unmultiplied speed is what the memory clock works off of, and why you can start with PC1600 and get away with it. If you bought PC2100 (266MHz/2=133MHz), you can run the system bus at 100, but you should be able to run the RAM at 133MHz and give yourself more memory bandwith. L1 and L2 cache operate at the same speed as the CPU's speed; in your case, that 1.7GHz. I could go in pretty deep with the varying speeds, but I don't want to lose you over something that doesn't really need to be explained to help you.
