More O\C oddness...

[aggressor]

2.4C
Abit IC7-G
Twinmos Windbond CH5 sticks (2x512)

At 200FSB with 1:1 memory ratio, 1 stick will complete Memtest 86 without errors.
At 250FSB with 5:4 memory ratio, 1 stick will get tons of errors.

Does anyone have a reasonable explination? At both settings they are running at the same speed (200mhz, what it's rated for), so I don't get whats going on.

 

[Duvie]

Do you have cache on in memtest??? I believe that will check cpu (800fsb versus 1000!!! Could be stressful) but also I believe that memtest does and will show mobo limitations (chipset) which could be showing with a 250fsb.....

Also it could be some mobo quirk regarding the 5:4 ratio and it needs a bios fix...

I could be wrong about above but I do believe memtest may test cpu (if cache is turned on) and memory subsytem...

 

[aggressor]

Yes, Cache was on. I'll turn it off and do more testing...I thought this would only test system memory, not the CPUs as well. Besides, all the memory errors happen on the System mem...

 

[aggressor]

I just tried 3:2 memory ratio @ 250mhz FSB, and the test completed without errors. Looks like it isn't the CPU.

 

[Duvie]

Originally posted by: aggressor
I just tried 3:2 memory ratio @ 250mhz FSB, and the test completed without errors. Looks like it isn't the CPU.

At 3:2 then the ram is running like 333mhz ddr so I imagine the timings were as agressive as they get??? There could be a glitch that needs a bios revision with the 5:4 ratio....Did you try 5:4 at all ram timings??? Did you try a touch more vdimm...May want to try all this stuff to see if you can unlock what may be going on...

 

[snowwie]

memtest is sensitive to a lot of things for me

I could relax all my timings, and make my ram 1:1
and errors, unless I upped my AGP voltage one notch

 

[Spicedaddy]

What mem timings?

Make sure Performance Mode is disabled (it's with the memory timings) in the BIOS.

 

[aggressor]

Performance mode has been disabled for all of my overclocking\testing.
Memory settings were 2.5\3\2\7, which is what the stick is rated for, but I do not see how this matters, as in both tests the memory was running at 200mhz.

 

[Duvie]

remember the ram still has to communicate through the northbridge chipset on the mobo and therefore the mobo has some effect on it....Could it be heat of NB?? Maybe but it passed at 3:2 ratio, right??? Could it be voltage?? Possibly a boost needed cause the mobo running high fsb and higher ram speed may be causing some power issues.....

You never know for sure but I am sure the mobo can contribute to this problem...

Also just cause a stick is rated that doesn't mean the mobo can handle it or is necessarily doing it right.....Try 2.5,3,3,7 instead of the 2.5,3,2,7...play around a bit...

 

[aggressor]

Duvie, I HAVE been changing the timings on the memory. I've been at this for 2 days now.

I cannot figure out the reason why 200mhz FSB 1:1 works fine, 250mhz FSB 5:4 crashes, and why 250mhz FSB 3:2 works fine.
It just doesn't make much sense :\

 

[Duvie]

Lets look at that simplified....

1:1 was done with a lower system bus 800 vs 1000.....

5:4 had same ram speed but bus was a lot higher...

3:2 was same bus at 5:4 but the ram speed was 66mhz slower....

So 5:4 had highest ram speed tested with highest system bus....

I think maybe power issues could be someting t look at .....rasie vcore a notch raise vdimm a notch and try again....

 

[aggressor]

CPU is at 1.7v already. Memory has always been at 2.8v.

Oh, and the power supply is an Antec Truepower 430.

 

[snowwie]

can you change the the AGP/NB voltage?
look at the northbridge hsf make sure the fan is working, try reseating it with some AS3 or something

 

[aggressor]

It's working fine. NB\CPU temps are fine. AGP voltage is at 1.55 (default).

 

[Duvie]

Originally posted by: aggressor
CPU is at 1.7v already. Memory has always been at 2.8v.

Oh, and the power supply is an Antec Truepower 430.

This may be the clue!!!! Go ahead and notch it up to 1.725v just for a test...Highly unlikley it will damage it if you just run a test....Does the board undervolt vcore, vdimm and/ or vagp???

 

[Spicedaddy]

Send the ram back...

 

[aggressor]

Why would it be a clue, Duvie? The CPU runs fine at 3.0ghz with 3:2 ratio...why would I need to give it more juice?

Spicedaddy: I plan to. I already ordered 2 sticks of Corsair XMS 3500 just to see if it's the memory :\

 

[Duvie]

Originally posted by: aggressor
Why would it be a clue, Duvie? The CPU runs fine at 3.0ghz with 3:2 ratio...why would I need to give it more juice?

Spicedaddy: I plan to. I already ordered 2 sticks of Corsair XMS 3500 just to see if it's the memory :\

I guess the clu would be if you need those volatges to run where you are at currently or if you just meant you tried all the voltages up that high..If it is the latter then I concur volatages is not the issue...BUt if you are maxed out on everthing to be stable now then power could be an issue...

Sorry if there was confusion!!!!

trust me I have seen when vcore can offer stability system wide.....

 

[aggressor]

I just tried all the voltages up to 1.7 for CPU. I decided to leave it there just so voltage wouldn't be a problem. Memory is maxed at 2.8 and won't go any higher :|

 

[snowwie]

try upping the AGP voltage a notch or two

It's done wonders for me in the past

 

[aggressor]

Will that damage the card? I'm running a 9800 Pro.

 

[snowwie]

AGP voltage is really the NB voltage

ever hear a northbridge be referred as the AGPset?

 

[Duvie]

Originally posted by: snowwie
AGP voltage is really the NB voltage

ever hear a northbridge be referred as the AGPset?

Hmmm!! I hadn't head that one....I may need to try that myself sometime....