conroe memory speeds?

Cyber-Mav

Cyber-Mav

Cyber-Mav

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gonna be going conroe soon, but have a couple of questions on the type of ram to go for, 800 or 1066 stuff?

can dividers not be used with slower ram to get more clocks?

is there a performance hit when not running 1:1 or does conroe not get effected much by not running 1:1 bus:ram? i remember my old athlon xp cpus, if i ran that on a divider it killed performance.

iv got a e2200 on order so stock 200mhz fsb = 800mhz final speed correct? since the bus is quad pumped?
so on that setup if 1066mhz ram was used there would be no bandwidth advantage since fsb can only communicate with ram at 800mhz and ram is 1066 so fsb is limiting factor.

im not sure but i think im confusing something with the bus, not sure if im supposed to see ram to fsb ratio as fsb being quad data rate vs ram being double data rate.

what do people see as a 1:1 ratio on conroe?
 
266*4=1066 is stock on an E6600 which would be running 1:1 with PC2-5400 (DDR2-533) so E2200 at 200*4 = 800 which would be 1:1 with PC2-3200 (which doesn't really exist any more)

You don't really see much gains running higher than 1:1 with a core 2 - but some applications do seem to take advantage of the higher memory bandwidth if you run the RAM faster than the FSB - I've never personally bothered to quantify it tho...

I don't think intel motherboards will let you run the RAM slower than the FSB.
 
ahh k, that helps clear some stuff up, so for ram to be running 1:1 with fsb the fsb speed is counted as half of its quad data rate speed?

would a future penryn cpu benefit from 1066mhz bandwidth? or should i just save the cash and go with 800mhz ram?
 
ahh i understand now, the final clock rates are not whats used to calculate the ratios? so 266fsb (ignore quad pumped) is 1:1 with 266mhz ram (which is ddr533).

is that right?
 
its my experiance that Intel Core2duos are diffrent than AMD with regards to MEMORY !
its more efficiant to run Intel with a 1/1 with tight timeings and as high mhz as you can

with amd its not so much important to run 1/1 but they do require on amds to run as high a mhz as you can with as tight as you can timeings...

amd = mhz
intel = tight timings.
 
I was trying to understand the quad pumped bit also.... I have a e6750 and ocz platinum rev 2 800mhz ram. Would fsb at 8x400 (CPU overclocked to 3.2ghz) mean the ram would run 1:1 800mhz? or as my friend seems to keep insisting would it be running the ram at 1600mhz? Assuming 8x400 fsb would mean 1:1 ram running at 800mhz (stock) if i up the fsb to 8x425 (3.4ghz) what should i set the ram to? I have EVGA 680i mb, e6750 proc and OCZ 6400 2x1meg ram (OCZ2P800R22GK)
Many thanks for any help.
 
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When you set the RAM to run 1:1 synched with the fsb at 400Mhz then the memory is also at 400Mhz (800Mhz effective double data rate), so your friend is talking from behind.

At 450FSB the RAM is at 900Mhz which the OCZ should be able to handle anyway if you increase the voltage a little and lose the timings to 5-5-5-15. Thing is with Intel chipsets you can't set memory to run slower than sync 1:1.
 
Actually on the 680i boards with 400FSB the linked memory speeds for 1:1 do show 1600MHz - you have to select sync mode instead - some boards do actually call it 2.0x or 2:1. But when you _are_ actually running the memory at 1:1 ratio with a 400MHz FSB then it would be running at 2x400MHz :D


Yes its confusing...
 
Yeah the 1:1 option on NV boards is actually 1:2 with the RAM running twice as fast as FSB. But they are the only C2D boards that allow running memory unlinked so you can still overclock the CPU and still keeping the RAM speed low.
 
8x1600FSB L/S = 800MHZ DDR2 1/1
8x1800FSB L/S = 900MHZ DDR2 1/1
8x2000FSB L/S = 1000MHZ DDR2 1/1

--------------------------

Hope this helps..
 
One other thing its not really recommended to go over 1866FSB on Nvidia boards.
other wize you rist saturating the BUS! and in turn crippling your bandiwth throughoutput.
 
ViRuS2k said:
One other thing its not really recommended to go over 1866FSB on Nvidia boards.
other wize you rist saturating the BUS! and in turn crippling your bandiwth throughoutput.
Click to expand...

Not much risk of that then... most nVidia boards struggle to reach 1800+ FSB.
 
hmm thanks for your help, still a little confused lol.

I just built the machine tonight so havent even turned it on yet (crosses fingers). I`ll be a couple of days sorting stuff out - operating system etc but i will return here and ask more questions if u chaps dont mind. I would quite like to keep the ram at safe levels while i experiment with the cpu overclock, but once thats sorted i'll concentrate on the ram and will probably ask u guys for some specific settings advice.

Cheers.
 
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