Can't pass stress test with ram

I fail the stress test in like 12 seconds when doing Large FFT. Could someone explain the difference?
When doing Small FFT's - stress CPU its fine but once i move on Large FFT's - stress some RAM i fail.
Faulty RAM? or something else. Im slowly learning how to OC my CPU, RAM is more confusing to me.

CPU: e6850 @ 3.7Ghz
Cooler: Ultra Carbon X7
Temp: While its being stressed in 68C

Could someone try to explain. Thanks

Its because your Ram isn't matching up with your FSB! I Mean when you overclock by changing the FSB, it affects the Ram as well! You must have seen the DRAM Ratio In your Bios Settings, that is the ratio between your FSB and the frequency at which your Ram Runs!

For Eg. 1 GB DDR2-6400 @ 800 Mhz means that the Ram runs at 800Mhz (Yes, u can go above that, but it depends on the quality of the Ram)!
But 800Mhz Ram means that the frequency is 400Mhz(1/2 Of The Specified) Because Ram nowadays is coupled(a pair)
So 800mhz = 2 x 400 Mhz! So in the Bios You Don't want to get the RAM Frequency above 400 Mhz if possible!

So if your DRAM ratio is 1:1, Den At 400 FSB Your RAM is at 400 Mhz And So You're Ok!
But If The Ratio Is 3:5,Den At 400 FSB Your RAM Will Be At 240 Mhz, Which Is Way Below 400 Mhz!

Seeing That you got upto 3.7Ghz, I think You have a really high FSB And The DRAM Ratio isnt Set Right! So Just Fiddle With The Ratio And Get It Right AccordinG To Your RAM!

If You Are Still Facing Problems Then You Hav To Set The Timings, So For RAM Timings Read Here, Excellent Guide:-
http://www.overclock.net/faqs/2670 [...] mmies.html

And You Should Try Upping Your RAM Votagle Too, But Dnt Exceed 2.144 V, Thats a bit too high!

Ok well FSB is 465MHz * Multiply 8
6-6-6-18 - 2T
Ratio is 1:1
The RAM is Kingston PC2-6400 (400MHz)

There is your problem. You don't want to overclock your ram.

Your 800mhz ram is running at 930mhz. It won't last long at that speed. I'm surprised it hasn't burned up yet.

Did u mean a heat spreader? IF so then no.

OK now im confused. i thought i was just overclocking my e6850. How did i end up overclocking my RAM as well

Or use a different ratio for the FSB:RAM...

Sigh. Although everyone is correct with regards to your problem, there's a lot of misperceptions here. (All except you, Wolfram ).

dj, you have the right idea, but you have the ratios backwards. FSB:RAM ratio of 1:1 means that the FSB and RAM are running synchronomously. For DD2 RAM, the memory clock is twice the FSB freq. 1:1 is best for stability. 2:1 means the memory is running at half speed. The first number is the FSB. 1:2 means that the memory is running twice as fast as the FSB freq.

DDR3 doesn't work that way. DDR3 RAM has a RAM clock 4 times the FSB. With a 1:1 ratio using DDR3, a 400 MHz FSB freq produces a ram clock of 1600 MHz.

2.20 volts is safe for DDR2 RAM.

Running the RAM much faster than its rated speed will not damage the RAM. As you can see, it just will not work.

Star, you did not say what kind of motherboard you have. If you have a motherboard with an nVidia nForce6 or 7 chipset, you can uncouple the the mem clock from the FSC freq and set it independently. Otherwise, with the Intel chipsets, when you increase the FSB, you increase the memory clock.

You can try to set a lower FSB:RAM ratio like Wolfram suggested. Or you can try the other trick in the Overclocker's Toolbox.

Increase the RAM voltage to 2.2 volts. Then relax the memory timings. If your memory timings are 4-4-4-12, try relaxing them to 5's-15 (or if they are 5's-15, try 6's-18).

Going from 4-4-4-12 to 5-5-5-15 will decrease memory i/o about 3%, but will have an insignificant effect on overall system performance.
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Overclocking since 1978 - Z80 (TRS-80) from 1.77 MHz to 2.01 MHz

Because your raising the fsb, which overclocks your ram.

The ratio your using (1:1) is causing your ram to run much faster than it's made to run, which will result in failure if it hasn't already.

You really shouldn't dabble in overclocking without understanding how it works first.

"with ddr3 it's recommended to use 1.5v with 1.65v being the max"


Where did you get that from?? There is 1.8v DDR3, that works perfectly fine in certain systems.

I think what you meant to say is "With Sandy Bridge cpu's, it's recommended to use 1.5v DDR3 with 1.65v being the max".

Your welcome for the correction.

Thanx jsc!
i really know when am doing it.. .. i mean, i got my e4500 upto 3 Ghz and did the Ram ratio, and timings perfectly.. But when i put that into words, KABOOM! ... :-)

And, Upping the voltage to 2.2 on a PC2_6400 Ram isn't advisable! 2.14 would be the max i would suggest somebody, But My DDR2_400 runs fine at 2.08 V!

OK well im using a p5k-e mobo
ok well now its

415x9 = 3735Ghz

Yet im still failing...should i drop it to 400 to keep it 1:1 or should i up the voltage?

Well There are boards who don't support changing DRAM Ratio(I had one).. Maybe His is one lyk That, is it ?

And Yeah, I Meant Running 1.8V Ram @ 2.2v Is Very Un-advisable!