DDR2 1066 compatibility
Wondering if DDR2-1066 memory will work in an ASUS P5B MB with 1066/800/677 MHz FSB, Intel P965 ChipSet, and dual channel memory architecture specified (in 2006 user guide) to support DDR2-800/677/533 memory. The installed processor is a 2.13 GHz Intel E6400 Core 2 Duo 1066 MHz FSB with 2 MB L2 cache. No clear answer using ASUS, Crucial, & Kingston sites.
fpsdominator said:well is should work fine, because the memory will just underclock itself to 800 mhz. and if it doesnt do it itself just go into the bios and set it at 800mhz.
actually most 1066mhz memory i bought ran at 800mhz for compatiblity and then you have to set to correct speed yourself.
thanks for the reply - i'm curious, though; can you tell me what is it that would cause it to clock down (or need to be clocked down), since the FSB of the MB and processor are capable of 1066?
Yes, fsb can be 1066 but thats not the actual speed of the bus, the base clock is 266MHz, but it can push through 4x more information in each clock cycle(its called Quad Pumped fsb, 4x266=1066). It seems max "officially" supported memory speed on that mobo is 800, so thats the speed this memory will by default run at. But from what i see on asus forums it gives full set of fsb:ram ratios along with the 1:2 which on fsb 266 would give ram speed of 533MHz and that equals ddr2 1066, you would just have to set the speed voltage and timings manually. I also see several posts from people succesfully running their ram at 1066 so i guess it is possible(though BIOS update might be required to achieve that).
It seems that this board is a fairly good overclocker, so you can try to push the fsb beyond 266mhz, which would make both cpu and ram run faster. But if you have any interest in that than read the great OC guide on top of Overclocking/CPU section of the forum.
Robert_74 said:Wondering if DDR2-1066 memory will work in an ASUS P5B MB with 1066/800/677 MHz FSB, Intel P965 ChipSet, and dual channel memory architecture specified (in 2006 user guide) to support DDR2-800/677/533 memory. The installed processor is a 2.13 GHz Intel E6400 Core 2 Duo 1066 MHz FSB with 2 MB L2 cache. No clear answer using ASUS, Crucial, & Kingston sites.
First of all DDR2-1066 isn't an actual specification.
All current DDR2-1066 is actually DDR2-800 that's been rated at an approved overclock setting. All DDR2-1066 WILL be detected as either DDR2-800, DDR2-667, or DDR2-533 by your motherboard.
So you have to overclock it.
Now, as for your FSB, it's 266 MHz. DDR2-533 is also 266 MHz. The difference is that the FSB is Quad, rather than Dual, data rate.
FSB-1066 is sychronous with DDR2-533 memory! Of course there's the problem of quad having twice the data rate of dual, but that's why they came up with dual-channel memory controllers. DDR2-533 in dual-channel mode has the same bandwidth as FSB-1066.
So, DDR2-1066 will work becaue the board will detect it as something slower. You'll have to overclock it to get 1066 MHz data rate, but you don't need 1066 MHz data rate.