2 different sticks refuse to run in dual channel. Help!

I have 2 double sided sticks of 512MB.
One is ADATA DDR500 rated 2.5-4-4-7@200 and 3-4-4-8@250
Other is Samsung TCCC DDR400 rated 2.5-3-3-7@166 and 3-3-3-8@200.
(By spd).

The Samsung can do 3-4-3-11@242 single , AData can do 3-3-3-11@250 single but they generate PRIME95 errors at 3-4-4-11 all the way to 232Mhz.

So far I've only tried D26 CPC-on bioses, gonna try the -off .

what else can I do? thanks.

how much voltage are you giving them?

Definitely, using CPC will be harder when using 2 sticks.

Have you increased chipset voltage?

2.9V for the memory, 1.7V for the chipset 1.7V for AGP bus, which I somewhere read helps to stabilize high fsb setting.

Memtest stops generating errors at 215(!) Mhz at 3-4-4-11, then I get to windows to run PRIME95, which doesn't fail.
But then I get a system reboot at random time.
Temps:
CPU:2.38~[email protected] (Voltage is OVER minimal stable) : 38-45C
Ambient:21-25C
Chipset:36C(single channel), 46C(dual channel mode).

voltage to the AGP bus should not be increased unless you are having video card related issues.

System reboots can be from many things. Usually, they are caused by overheating components, unstable memory/CPU, or power fluctuations beyond the norm by your PSU.

Know Nuttin: you are absolutely right.
The reason why I posted my system temps - to show that nothing is overheating.
The main "rebooter" from my experience too is "severely" unstable CPU /bad PSU signal/completely messed up memory.

General CPU/memory instability can cause explorer crash/"error report" screen/Prime errors.

Memory/CPU errors can usually lead to BSOD as well.

However this is not the situation as I trust my PSU, no errors during Prime95 test, just reboots.

My problem is that I never before observed chipset related errors on my system and I don't know it's behaviour.

Even my previos "stolen" NF7 could run 255 fsb with no hiccup.

remember u have 2 different modules and even tho they run great in single channel there is a variation of accesstime for each module. for instance ,when u run 3.3.3.11, each module responds slightly different cause they are different chips. that coupled with running dc can sometimes cause these probs. i would start out with the loosest timings with everything off (cpc etc.) then crank up the voltage to the dimms nb/vagp as much as u can. then start testing. once u find the top end at 3.4.4.8 bump the timings down a tad ie 2.5.3.4.8 and see how that works. once u find a good sweetspot try turning on the tweeks 1by1. i know this sounds like alot of work but this is the best way to optimize ur memory. evildoer was gonna get rid of his ocz pc3700 eb cause it wasnt running right. well he hung in there and tested some more and presto hes got it running great. If u still cant get any better then u may want to consider purchasing 2 stix of the same stuff. also, sometimes there is a big variation in the oc'ing ability of the same mb's just like ram, some will oc great and some wont, even tho they are the same chips...

Thanks for the input flapperhead.
Yes there are a lot of variables to take into consideration, and that's what I'm doing last 3 days.
The problem is that when I finally find a reasonable stable setting, it would reboot nevertheless. I'm starting to think that the reboot is caused by the interaction between the chipset and lan chip. Maybe I should make a better cooling for NB and a fan to SB.

If u still cant get any better then u may want to consider purchasing 2 stix of the same stuff

Click to expand...

I guess eventually that's what I'll do.

I'm now running on single ADATA with most stable bios , anything stable, but the random reboots are still there.

I think I'm startin gto lose the fun here.

man i hate that. ive got an ic7 that i totally modded out and didnt test each mod . now there is a problem and i gotta find it. it aint gonna be fun trying to figure which of the 5 mods is bad..
getting back to u.. sounds like u need another guy to test out the stix with the same mb..

Thanks for the help and good luck with the IC7.

I'll find someone to test me the memory; right now I'm taking it slowly from 200 Mhz again.

As silly as is sounds to some of us, there is a reason that they make dual-channel kits with "matched memory". Dont beat a dead horse, get two sticks that are at least from same series. I dont completely agree with the "match set" kits, but at least you know they work together, for the most part.