So I'm building a new system with a P4 2.8 and an ASUS Mobo. I hear RDRAM may not be worth it for the money, but I will prob. be able to afford it. How much better is RDRAM 1066 than DDR 333mhz? If I use DDR can my FSB run at 533mhz? Is it worth it for the price?

RDRAM (Rambus DRAM) Pronounced "RD RAM." A dynamic RAM chip technology from Rambus, Inc., Mountain View, CA, (www.rambus.com). In 1995, Base RDRAM was introduced with speeds up to 600 MBytes/sec. In 1997, Concurrent RDRAM increased speed to 700 MBps, and in 1998, Direct RDRAM boosted speed to 1.6 GBps. Concurrent RDRAMs have been used in video games, but Direct RDRAMs are used in computers. Direct RDRAM chips are housed in RIMM modules, which are similar to DIMMs, but have different pin settings. Direct RDRAM chips can also be built with dual channels, doubling the transfer rate to 3.2 GBps. Rambus licenses its memory designs to semiconductor companies, which manufacture the chips. Intel has invested in and has been involved in the design of the Direct Rambus SDRAM (Synchronous DRAM) A type of dynamic RAM memory chip that has been widely used starting in the latter part of the 1990s. SDRAMs are based on standard dynamic RAM chips, but have sophisticated features that make them considerably faster. First, SDRAM chips are fast enough to be synchronized with the CPU's clock, which eliminates wait states. Second, the SDRAM chip is divided into two cell blocks, and data is interleaved between the two so that while a bit in one block is being accessed, the bit in the other is being prepared for access. This allows SDRAM to burst the second and subsequent, contiguous characters at a rate of 10ns, compared to 60ns for the first character. SDRAM (Synchronous DRAM) A type of dynamic RAM memory chip that has been widely used starting in the latter part of the 1990s. SDRAMs are based on standard dynamic RAM chips, but have sophisticated features that make them considerably faster. First, SDRAM chips are fast enough to be synchronized with the CPU's clock, which eliminates wait states. Second, the SDRAM chip is divided into two cell blocks, and data is interleaved between the two so that while a bit in one block is being accessed, the bit in the other is being prepared for access. This allows SDRAM to burst the second and subsequent, contiguous characters at a rate of 10ns, compared to 60ns for the first character. (ddram) SDRAM provides 800 MBps or 1 GBps data transfer depending on whether the bus is 100MHz or 133MHz. Double Data Rate SDRAM (DDR SDRAM) doubles the rate to 1.6 GBps and 2.1 GBps by transferring data on both the rising and falling edges of the clock.

Yeah... but what about RDRAM 1066 vs. DDR 333mhz..... these are the two newest and fastest which is faster?

Well thank you for the complete history Brown :-) Firstly ensure your mobo can take DDR. I'm sure if the mobo is a new pentium one you should be ok there. As far as is it worth it or not, well it seems to be often very dependent on your chipset and so on. I would personally say it's not really worth the extra cash. Finally the FSB speed will not change if you install 333MHz, you set a ratio in the bios which determines how fast your RAM runs compared to the FSB speed.

I've read a couple articles and it seems to be a toss up. It really depends on your mobo and what your using it for. One thing I have read is that RDRAM has to be upgraded in pairs and I think the pairs must mach too, not sure. So if you want to buy and add some RAM, u have to buy two sticks of the same size. With DDR it works the same as SDRAM, just but whatever you want and through it in with what's there. Check out this site for major info on hardware including RAM types and which is best for what: http://www6.tomshardware.com/