DDR = Double data rate
DDR1066 is actually running at 533mhz, it just sends data on the up slope and down slope of each cycle (hertz), so the 1066 is an "effective" number, meaning it matches the speed of 1066 non ddr devices.
Little memory history:
Im going to skip EDO and SIMM memory, since it is before most of yalls life time (I had the joy of messing with SIMM in my old 486-25).
I am going to stat with DIMM memory (which we still use):
PC 66 (ran at 66hmz on computers with 66mhz boards, P1 and some P2s)
PC 100 (came out with the upper P2, like the P2-400 ran on a 100mhz board)
PC 133 (P3 days, 133mhz board)
Then DDR came out
DDR266 (133 board and memory)
DDR333 (166mhz ....)
DDR400 (200mhz board)
DDR500-600 were both non standard (400 was the highest standard)
DDR2 is just a specification change (new socket, new specs, new voltage)
DDR2 533
DDR2 600, 675, 800, 1066... you get the point
DDR3 was another tech upgrade, still just double data rate, lower volts, etc
There is also GDDR (graphics) and GDDR5 is actually QUAD data rate (1600 = 400 actual mhz).
Also, your board speed does not dictate the exact memory speed, just like the cpu it has a multiplier.
So you can have a 200mhz board speed, and ddr2800 memory if you set your memory to 2x. Most of the ddr2-800s are done by a 266 bus and a 1.5x memory multi (1066fsb fsb=4x bus speed, fsb is quad data rate on intel machines). The later intels use a 333 bus (1333 fsb), mine has this, but mine is overclocked to 440 bus (1760fsb) and 1.2 memory multi = DDR2 1056 (its DDR2 1066 so works perfect).
Core2 machines do NOT thrive on high memory performance, but low latencies are what help. The way the fsb is created with the Core2 machines are that the max bandwith the chip can saturate is 2x the bus speed. So if you have a 1066fsb chip (266board) all you need is ddr533, and the 1333 (333) only need 667mhz memory, it wont hurt to put faster memory, but it will never use the full speed of it, you are better off making sure your memory is like 5-5-5-15 or below, not some 6 cas latency memory (5 wait cycles vs 6 = 20% better memory performance all from just 1 little number). My memory is 1066 @ 2.0v 5-5-5-15
Memory voltage is different from CPU voltage in that more voltage does NOT mean more speed. Your memory has a set voltage, like 2.0-2.1, run it in that voltage, higher or lower voltage will make it unstable, and high will kill the chip very fast. That being said, auto DOES NOT SET IT CORRECTLY in any machine I have built. Auto for DDR2 = 1.8v PERIOD. 1.8 is the "official DDR2 voltage" but you really need to look on the chip label itself or in CPUZ for what voltage to set it to. Gigabyte boards use a +xx option, like if you want 2.0v, you need to set it to +.2v (1.8+0.2=2v) simple enough, but dumb if you ask me, why not just put the number there (like my DFI x48 does)...?
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-- .:Splak|StackableNut --Cornholio wrote:
blah thats nothing, i built houses for pirates, then do pirating myself. Then I shoot my self and perform bullet removal surgery on myself. After that I go to boot camps to train kids to kill. Then i go and fight on the Iraq war for both sides. After all i go later and drink some 7up cause ill be thirsty as shit.
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