All this RAM talk is giving me a headache :-)

I'm trying to reach a decision on which RAM to use in a system I plan to build over the next couple of weeks, but I'm having trouble figuring out all the various RAM options.

I plan to go with DDR RAM and of the motherboards I'm considering, all state they support DDR266. So what are my options now ? What's the difference between PC2100, PC1600 etc. ?

...and then along comes DDR333. What's the difference between this and DDR266 ? Any suggestions for a mobo that supports DDR333 (so I can go and perhaps re-think my current mobo decision).

Many thanks for any and all help.

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  1. What is your chipset CPU

    That the 1 spec you give

    The day i meet a goth queen that tell me Intel suck.I turn in a lemming to fill is need in hardware.
  2. I was planning to go with the Intel 845E.
  3. OK, DDR200 is called PC1600 and runs at 100MHz (they double the MHz in the name because it's DDR).
    So DDR266 is called PC2100 and runs at 133MHz
    And DDR333 is called PC2700 and runs at 166MHz
    And DDR400 is called PC3200 and runs at 200MHz

    The best solution for the i845E chipset is PC3200. It's not very expensive either, around $80 for a 256MB module.

    Most performance boards with the Intel chipset will allow you to use the 3:4 FSB/RAM speed ratio at any clock rate. That means "DDR266" with Intels 100MHz "QDR400" CPU bus. But for overclocking, it means "DDR354" speed with Intel's 133MHz "533" bus. This is too far to overclock most PC2700, which means you would be best of with DDR400, aka PC3200.

    Most people in this forum buy the 1.8A for its overclocking ability. At 133MHz bus speed, it will run 2.4GHz. If your lucky enough to get the CPU to 150MHz FSB, it will be 2700MHz. At 150MHz FSB, using the 3:4 ratio for memory speed, you would be at exactly 200MHz memory speed, or DDR400, which is what PC3200 is garunteed to run at.

    I haven't checked around for value prices on PC3200, the $80 I quoted for 256MB happens to be the price I saw it at from (who, just to confuse people, puts it in the "PC3300" memory catagory, even though it's called PC3200).

    <font color=blue>By now you're probably wishing you had ask more questions first!</font color=blue>
  4. Have a cup of coffee and Analgin! ;-)))
    If you have enough money, grab DDR-400. If your mobo supports it (as the newest SIS chipsets do) will be good, but this is not necessary to feel the difference between DDR-400 and the slower ones.

    <font color=orange>ÃÎËßÌ ÇÀËÚÊ ËÀÏÍÈ, ÃÎËßÌÀ ÙÀÍÃÀ ÂÄÈÃÍÈ!</font color=orange>
  5. Okay, that helps a lot. Many thanks. I'm still not clear on the finer aspects of the memory speeds, but I think I see where you're going.

    Depending on how far I can stretch the budget, my plan is to use a P4 1.8a GHz, or maybe a 2.0GHz or maybe even a little higher. The mobo I have in mind is either the Asus P4B533-E or the Gigabyte GA-8IEXP. I figure I'll stay with the DDR266 based boards since they fit into the budget better, but still offer reasonably good performance. Graphics will be a Visiontek GF4 Ti 4600. With all this in mind, would PC3200 still be a good option ? i.e. it seems some P4 CPU's are better suited to OC'ing, which would be required to get the most out of the PC3200, right?

  6. Yes, some P4's overclock easier than others. Basically, the 1.6A, 1.8A, and 2.0A all have similar "Max Overclock" speeds. So you'll get your highest possible bus speed with the 1.6A, your next highest with the 1.8A, and your least high bus speed with the 2.0A (out of those three).

    The 1.6A is almost garunteed to run at 150MHz FSB. That's 2400MHz. The 1.8A is almost garunteed to run at 133MHz FSB, that also 2400MHz. The 2.0A is likely to reach similar clock speeds as the other two, but 2.4GHz comes at only 120MHz, which is not a good choice for bus speed.
    Any of these three are likely to reach 2.5GHz.

    The chances of reaching 2666MHz with any of them is not that good, which is why I don't recommend the 2.0GHz, the basic 133MHz FSB overclock often won't work for it.

    You could get an inexpensive 1.6A and clock it up to 150MHz FSB/2400MHz, with the 3:4 FSB/RAM speed ratio, the memory runs at 200MHz, which is the speed that DDR400 "PC3200" is supposed to run at. All memory can run at slower clock speeds, but you loose the performance advantage of using faster memory that way.

    If you want to try higher than 2400MHz, I suggest the 1.8A. At 150MHz FSB, it would be running 2.7GHz. But even at 133MHz, it would reach 2.4GHz, and with the 3:4 memory ratio, give you 177MHz, which exceeds PC2700 spec but doesn't even begin to stress PC3200.

    <font color=blue>By now you're probably wishing you had ask more questions first!</font color=blue>
  7. "Ding"....and the light comes on. Many thanks Crashman. The fog is clearing and it's beginning to make sense :-)

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