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Max FSB not compatible with memory?

Forum Motherboards & Memory : Memory - Max FSB not compatible with memory?

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falconzfan007   04-09-2009 at 09:52:06 AM

For DDR3 memory, I heard that you divided the MHZ by 4 to find the maximum FSB that will work when you overclock. So if i have 1600 MHZ RAM (Which i believe is the highest), the highest FSB i can have is 400? And with a Q9550 locked at 8.5x multiplier, does that mean i cant go past 3.4 GHZ?? that doesnt make sense...
Can someone please help me out? thanks!

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Dekasav   04-09-2009 at 05:25:09 PM
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You heard wrong. DDR(1/2/3) are double pumped, not quad. Your FSB is quad-pumped.

So at 400Mhz FSB, you run an effective 1600Mhz FSB, and run DDR1/2/3 at 800Mhz (at the standard, usual, 1:1 ratio)

Basically, you can pump your FSB as high as you want, because your CPU or Motherboard won't make it to 800Mhz base FSB. (This is why I have no idea why anyone uses DDR3 for Core 2's)

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Helloworld_98   04-09-2009 at 06:41:22 PM
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if you had serious cooling you could go upto 6.8ghz with that ram but I wouldn't try it. And 2.2ghz is the max ddr3 I could find.

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falconzfan007   04-09-2009 at 08:54:37 PM
- 0 +

Dekasav wrote :

You heard wrong. DDR(1/2/3) are double pumped, not quad. Your FSB is quad-pumped.

So at 400Mhz FSB, you run an effective 1600Mhz FSB, and run DDR1/2/3 at 800Mhz (at the standard, usual, 1:1 ratio)

Basically, you can pump your FSB as high as you want, because your CPU or Motherboard won't make it to 800Mhz base FSB. (This is why I have no idea why anyone uses DDR3 for Core 2's)




so that means i am using a 1333 mhz DDR3 RAM, i can have a FSB of 666 and have a 1:1 ratio? im not really understanding the whole double pumped/ quad pumped thing. You said "So at 400Mhz FSB, you run an effective 1600Mhz FSB, and run DDR1/2/3 at 800Mhz (at the standard, usual, 1:1 ratio)." So with a 400 Mhz FSB, how can i run a 1600Mhz FSB?

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cjl   04-10-2009 at 04:30:49 AM
- 0 +

1:1 is overrated too though. Go as high as you can with the FSB, and then pick a RAM ratio that will get you closest to DDR3-1600. You don't want to go under 1:1 typically, but there is no reason to underclock your RAM that drastically just to achieve a 1:1 ratio.

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------------------------------ Asus P6T deluxe
i7 965 @ 4.2GHz (200*21), 1.384V
12GB Corsair Dominator DDR3-1600 CAS 7
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falconzfan007   04-10-2009 at 04:48:50 AM
- 0 +

cjl wrote :

1:1 is overrated too though. Go as high as you can with the FSB, and then pick a RAM ratio that will get you closest to DDR3-1600. You don't want to go under 1:1 typically, but there is no reason to underclock your RAM that drastically just to achieve a 1:1 ratio.



How exactly do I acheive a 1:1 ratio with DDR3-1333 RAM?

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cjl   04-10-2009 at 07:03:16 AM
- 0 +

Set your FSB to 2666 MHz effective (667 base clock).

Good luck.

Message quoted 1 times
------------------------------ Asus P6T deluxe
i7 965 @ 4.2GHz (200*21), 1.384V
12GB Corsair Dominator DDR3-1600 CAS 7
 Reply to cjl
falconzfan007   04-10-2009 at 08:13:54 AM
- 0 +

cjl wrote :

Set your FSB to 2666 MHz effective (667 base clock).

Good luck.




When you say 667 base clock, are you refering to the FSB of the processor? Because thats really high when i use my 8.5x multiplier.

Reply to falconzfan007
cjl   04-10-2009 at 08:59:07 AM
- 0 +

That's my point. You'll never in a million years manage to pull off a 1:1 ratio at 1333 RAM speed unless you're using liquid nitrogen.


Message edited by cjl on 04-10-2009 at 08:59:25 AM
------------------------------ Asus P6T deluxe
i7 965 @ 4.2GHz (200*21), 1.384V
12GB Corsair Dominator DDR3-1600 CAS 7
 Reply to cjl
Brandon00000   04-10-2009 at 07:24:58 PM
- 0 +

falconzfan007 wrote :

For DDR3 memory, I heard that you divided the MHZ by 4 to find the maximum FSB that will work when you overclock. So if i have 1600 MHZ RAM (Which i believe is the highest), the highest FSB i can have is 400? And with a Q9550 locked at 8.5x multiplier, does that mean i cant go past 3.4 GHZ?? that doesnt make sense...
Can someone please help me out? thanks!



all you have to do is unlink it then you can increase your fsb as much as you like just keep your ram at max speed and make sure in the bios you have it selected to unlinked instead of linked then when you increase you fsb your ram will stay the same

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