Memory divider unstable?

[Dutch Guy]

Saturday I have been trying to overclock my system only to find very strange instability at booting and lockups.

Could it be that my system/mobo does not like to run the memory at a divider, can that cause instability? (even if the memory is running at 183Mhz)

[edit]Example: I ran Prime95's small FFT test for 100 minutes without error at [email protected] with the memory at a 150Mhz divider so it's at 204Mhz and I get a lockup in Windows after the Prime test and at reboot it hangs again at/after Verifying DMI pool and even at 11*250Mhz, I had to set it tos tock to get it to boot again.

So should I test the max. memory speed first and use a 1:1 divider from then on?[/edit]

 

[weescott]

The memory controller on A64 chips can be flakey at around 270fsb, so no matter what your ram can do it could be the memory controller holding it back.

 

[Dutch Guy]

The memory controller on A64 chips can be flakey at around 270fsb, so no matter what your ram can do it could be the memory controller holding it back.

I agree, that's why After 10x272Mhz I tried 11x250Mhz which was the same

Everything points to a unstable system when running with a divider.

I think the only option is to test the max. overclock of my Ballistix PC3200 first and use a 1:1 divider to see if that helps, I just wanted to hear stories from other people that had the same so I know I'm doing the right thing instead of wasting more time overclocking.

 

[weescott]

Is your HTT multi @ 3?

You should keep your speed between 1600 and 1800, that would explain why the higher fsb is more stable.

272 * 3 * 2 = 1632 HTT
250 * 3 * 2 = 1500 HTT

 

[Dutch Guy]

Is your HTT multi @ 3?

Yes, I set it to 3x in all overclocking situations so that can't be the problem.

 

[tbz_ck]

I finally got around to overclocking my CPU on Sunday. I've got the same ballistix as you Dutch Guy and on my board (see sig) it was happy at a 5/6 divider.

Got the CPU to 2475 (11X225) with HTT at 4 all at default volts with a quick diddle in the BIOS.

Next task is to try a lower multiplier and higher FSB to get the RAM running at or around 200Mhz (DDR400). The Newcastle seems like it has more in it.

 

[n3x]

my system doesnt like it when i reduce the cpu multi to wack the fsb up above 300 hence the slow memory speed

 

[Dutch Guy]

Maybe the extra dividers on this DFI mobo like 150Mhz, 180Mhz and 190Mhz are not stable and only the standard ones like 133Mhz and 166Mhz??

I just wish I was home so I can test instead of work

 

[Street]

I've found that the DFI dividers aren't stable with some RAM. I had a play with my housemates new PC, same spec as mine. If I set the divider to 180MHz the system wouldn't boot at all. Even if I let the HTT at 200 and applid the divider. The 166MHz divider worked fine though, so assumed it was his RAM not liking the divider.

 

[Ladforce]

my system doesnt like it when i reduce the cpu multi to wack the fsb up above 300 hence the slow memory speed

Yep same if i run 9x305 i get a black screen with no boot but default multi x 305 boots fine. Strange problem. This is on a neo2 platinum.

 

[mp260767]

maybe update the bios if its not up to date.

sure the dfis used to have probs with ballistix but thought it had been sorted.

 

[Dutch Guy]

Yes, I found a link to a BIOS update CD on the DFI street forums so I will update the BIOS to a later one and see if that helps.
I will also overclock the memory first to see how fast I can run it stable, perhaps I am lucky and I can run my memory at 250Mhz or more so I can run at 1:1

I have been running the memory at the 150Mhz divider and that gave me weird stability issues and boot failures that would be explained by the fact that the mobo is unstable at that particular divider.

I'm glad I bought a 3700+ with a 11x multi so if I can get my memory at 260Mhz stable that will give me a CPU speed of 11x260 = 2860Mhz max that will do fine and perhaps the 166Mhz divider does work stable giving me even more options.

 

[Dutch Guy]

I have done some more testing and indeed I need to run a default 11x multi and memory 1:1 but I can get the memory stable at 260Mhz [email protected] which is better than I expected

 

[Big.Wayne]

Hi Dutch,

sounds like you had the same problem as me, and I think its the newer Ballistix doesn't like working on a divider with A64 (well at least my set doesn't). The PC would just hang after the irq listing screen?

I ended up just pushing it 1:1 until it wouldn't pass memtest anymore

Looking for a 2GB set now, but trying to *not* buy the OCZ0PC4000-EB or the CORSAIR 3500LL or indeed the Mushkin Redline

 

[Dutch Guy]

sounds like you had the same problem as me, and I think its the newer Ballistix doesn't like working on a divider with A64 (well at least my set doesn't). The PC would just hang after the irq listing screen?

I had exactly the same, had me stumped for a while.

But now it's much better, I never thought Ballistix would run at 260Mhz with 2.5-2-2-10-1T timings, just a shame my CPU needs >1.625V to run at 11x260Mhz and I can't use a lower multiplier.

 

[tbz_ck]

260Mhz @ 1:1 Nice

My ballistix are from December (when they were exchanged). Gonna have to try to get mine to at least 230Mhz where my CPU should be able to handle 2530Mhz...