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Could someone please explain to me..

post #1 of 6
Thread Starter 
why 1333mhz RAM can bottleneck your OC? If I set the DRAM multiplier to an appropriate amount so that the clock won't exceed the stock speeds I should be fine right?
Mike Wazowski
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Mike Wazowski
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post #2 of 6
what are your specs?
post #3 of 6
Thread Starter 
1045 T
990FXA-UD3
Corsair XMS3 + Crucial Ballistix ram rated at 1333mhz
SeaSonic G SSR 550M
Mike Wazowski
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post #4 of 6
I'm pretty sure that the PII 6 cores have a memory controller limited to 1333mhz, and they aren't very good overclockers when you compare them to some of today's CPUs. some can only get to around 3.6-3.8GHz
post #5 of 6

It's an issue of bus clock overclocking.

Due to low binning of generic memory kits (1333 CL9 is a bottom-end generic spec/standard) these kits are typically found with non-overclocking-optimized ICs that may stop short of hitting the speeds needed for hitting the high bus clocks needed for higher speed CPU operation. Most RAM companies just take the ICs out of a grab bag. All DDR3 ICs are rated for meeting minimum generic JEDEC spec standards, including those that will do the minimum speeds only but not the further. For example: your kit might top out at 1400-1425Mhz and then refuse to OC further. I've seen that happen. And when it does, whatever bus clock you get to is where your CPU is effectively stuck because the RAM cannot go any faster. You might be able to notch the multliplier down once more but it does not guarantee stability, due to a difficult timings config process that sometimes due to secondary timings standards may be impossible. A generic DDR3 kit prevents bus clock flexibility.

 

For locked-multi x6 CPUs, I recommend DDR3-1600 as an absolute minimum. At the high bus clock speed of 300Mhz you need to hit 4Ghz on your 1045T, you can run the x5.33 multiplier for exact DDR3-1600 configuration and set RAM config hassles aside. DDR3-1600 kits have usually costed similarly to generic DDR3-1333, occasionally (frequently occasionally, in fact) less than.


Edited by xd_1771 - 12/8/12 at 9:56pm
post #6 of 6
Thread Starter 
Wow absolutely awesome post. Answered all my questions smile.gif

Thank you
Mike Wazowski
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Mike Wazowski
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