need help on memory problem

[keyonman]

I just built a computer with the following parts:
DFI Infinity p965 with C2D E4300. I am using an Arctic Cooling Freezer 7 Pro CPU Fan and overclocked the CPU to 3.1 Ghz. I am running Windows Vista Business 64 bit and I have 4 Gigs of memory ( Crucial Ballistix DDR2 6400 ). I ran Memtest for each ram and each one ran fine for 24 hours without a hitch. I ran 2 Gigs and no problem . When I ran 4 Gigs of memory on memtest, I get an error after about 16 hours. I had another set of 2GB of same Crucial ballistix so I switched the memory to see if that will help. I still get an error after 12 to 16 hours. Can anybody tell me why this happens. BTW, I have the memory running at 3-3-3-12 timing. It is also underclocked slightly at 690 ( instead of the rated 800 Mhz).

 

[flyer335]

I have questions, but no answer.
Is this your memory-
Crucial 'Ballistic' BL2KIT12864AA804?

If so the Crucial product page shows-
4-4-4-12 • UNBUFFERED • NON-ECC • DDR2-800 • 2.2V.

I don't know that asking CAS 4.0 DIMMS to do CAS 3.0 would cause errors at lower speeds, but it might. Also, do you have the voltage set to 2.2V? Too low of voltage will cause glitches. Especially when maxing out DIMM population on the mobo.

Is this how you are running-
ddr-690 (345x2) ? FSB=1380 (345x4) ? 345x9=3105MHz ? 1:1 FSB|DRAM?

I'm curious if RAM reliability can be linked to the base speed of the memory modules used. For example- if DDR2-533 DIMMs have a base speed of 33.34 MHz, do they need to be operated at some multiple of that speed? ie: 33.34 x 8 = 266.8 x2 = 533.6 (DDR-533) or 33.34 x 16 = DDR-533; so to RELIABLY OC the DIMM or memory address bus should we be using something like (33.34x18) DDR-600, (33.34 X 19) DDR-633.5...etc?

If so, in your case I'd try a 1333.6 FSB (QDR), DDR-667 (333.5x2) for 3.0GHz CPU rated bus. I know it's a down-clock for you right now, but run that through memtest as you did your current clock and see if it throws errors. Then go right to 1467 FSB, DDR-734, for 3.3GHz.

However, I'm not sure the base operating speed for DDR-800 is still 33.34 MHz. I think it is increased to 66.7 MHz or higher so the multiples would be different.

Just a thought! I've been wondering about this for awhile.

TonyB.

 

[flyer335]

Have you tried running your RAM at the rated DDR-800, 2.2V @ 4-4-4-12? If so, did it error?

I do believe you are losing bandwidth and computing power by not running them at full rated speed. At least in a system with only 2GB of RAM you do.

 

[keyonman]

I am running my mem at 2.2V. The option on my MB BIOS had me running this mem at 533 345X9=3105 Mhz 1:1 FSB. I've read somewhere that using all four DIMM slots limit your overclocking ability. Like I said, I didn't get any error when running 1 or 2 sticks for 24 hours straight. Yes you're right, BL2KIT12864AA804 is my ram . I also tried the different DIMM slots earlier and that did not give me any problem when running 1 or 2 sticks. I also remember running 4 gigs at 2.1V 4-4-4-12 and also got an error. I am perplexed.

 

[nobly]

You are running your RAM beyond the spec.

Your RAM can handle 5ns CL rating (4T/800Mhz) = 5ns (effective) at 2.2V. Your current setup is (3T/690Mhz) = 4ns(effective). Its too much. You will have to downclock to 600Mhz or try to raise the voltage...

Run the RAM at its specified settings (if that is your RAM) - 4-4-4-12 at 2.2V as flyer said. If the errors still come up, reset your BIOS settings to default and try again. The RAM SHOULD run at its specified ratings. If not, then RMA them.

I have also heard that 4 sticks does limit the overclock, but I thought that was a thing of the past with DDR1. I might be wrong.

 

[Mondoman]

Y...
I have also heard that 4 sticks does limit the overclock, but I thought that was a thing of the past with DDR1.

No, there's the same issue w/DDR2 (although perhaps not so much with DDR3). Since the DDR2 we use, like DDR, is *unbuffered*, having 4 DIMMs installed means the signals sent to the DIMMs are split among 4 modules instead of 2 or 1, and so are weaker at each individual module.

 

[nobly]

Oh, thanks for the correction mondo! I just remember a slew of threads on it for DDR1, but less on DDR2.

 

[keyonman]

Y...
I have also heard that 4 sticks does limit the overclock, but I thought that was a thing of the past with DDR1.

No, there's the same issue w/DDR2 (although perhaps not so much with DDR3). Since the DDR2 we use, like DDR, is *unbuffered*, having 4 DIMMs installed means the signals sent to the DIMMs are split among 4 modules instead of 2 or 1, and so are weaker at each individual module.
Will this possibly explain why I have a problem with 4 DIMMs used? I don't think it is the memory since I swapped 6 sticks on the slots and got the same problem. I wasn thinking it might be a problem with the MB but you are probably right about each slots sharing weaker signals to each module hence the problem when running on all four. :x

 

[Mondoman]

Yes; the better quality the memory modules and the better quality the MB, the less the chance of having the problem.