Hello,

I recently built a new configuration as follows:

CPU: Intel Core 2 Duo E4600 2.4 GHz
Motherboard: Gigabyte GA-G33-DS3R
Ram: Two sets of Corsair 2x1024-C6400-C4 (4 x 1GB dim; 4-4-4-12, 2T, 2.1 v, 800 mhz FSB)
Graphic card: ATI Radeon HD 3870, 512 MB DDR3

The memory fails dramatically on memtest, but this only occurs when the 4 dims are installed. I tryed every memory separately, then in groups of 2, groups of three, using all slots. The modules have also been tested by my local retailer and the same result: memory modules are ok, motherboard is ok. If i put the 4'th module in it fails. I tryed almost all settings i could imagine in BIOS but it still fails.

I may add that i don't want to overclock, i just need this damn system to work.

Can someone please help me?

Here are my bios settings:

Increase Voltage and loosen timings to +.4v and 5-5-5-15 run mentest again.

Tried that but it still fails at INVC and STRIDE 6 tests.

I don't get that many errors now since i made the new settings you suggested but it's still enough to crash Vista 64 into the nice BSOD.

Can the cooling be an issue? I mean i don't have any other coolers than the CPU's, the graphic card's cooler and the power supply coolers (2).

Go a little more. add another .1v and 5-5-5-18

4 sticks is more of a load on your MB than 2x2GB would have been.

Stock voltage for that ram is 2.1V, which is what you currently have your memory voltage set to. Bump it up at least another .1V.
The mobo default voltage for memory is 1.8V, so your +3 setting is resulting in 2.1V, which is probably why you are having problems with 4 sticks installed.

The memory voltage is fine at 2.1V, although you can try 2.2V (no more!). The problem is that 4 sticks is pushing the limits of unbuffered memory technology; try boosting the MCH (memory controller) voltage by +0.1V.

^ I agree, but it may not help. I have seen more than a few people have trouble with 4 sticks.

You might also try lowering the speed to 667.

Yes. If the MCH voltage boost doesn't work, sept may have better luck by instead buying some *standard* DDR2 memory (rated at 1.8V) and using that instead. There's also the good choice of buying & using just 2x2GB modules.
sept - you might also ask for help on the excellent Corsair support forums (www.asktheramguy.com).

The advice to try "standard" 1.8V memory is good, I am running 4x2GB A-Data DDR2800 on an EP35-DS3R rev 2.1 at 2.0V although it appeared quite stable at 1.9V.

Thank you guys for all the replies. Tried raising the MCH, also lowered the FSB, still no luck. I will consider changing these dimms with 2x2GB but before that i'm ready to experiment a little bit more with these i have right now.

Here is a configuration i just made and memtest works for an hour (3 memtest pass) whitout an error:

FSB: 667 MHz
FSB Voltage: +0,1 v
DRAM Timings: 5-5-5-15 2T
DRAM Voltage: 2,2 v
Memory controller: +0,1 v

After pass 5 it failed. I start believing this is because of a bad system cooling.

Take off the +.1v on the MCH.

Did that, no luck, i get thousands of errors.

No, you're close but not quite there (unless you are seeing very high temps somewhere).

I tried almost all possible settings. I'm running out of possibilities

What are the temps?

Try setting the MCH to +0.2V

MCHes have an internal mechanism that regulates the strobe scew according to the temperature of the chip. Under very specific test conditions that includes a combination of low MCH core voltage, high
temperature and slow silicon you can get Timing Marginality on the Receive Enable. As suggested previouly setting the DIMM rail to +0.2V and providing better cooling to the MCH should correct your issue. The power consumption when using all 4 DIMMs will increase by about 0.75W per DIMM. So you are looking at 3W for 4 DIMMs.

You may also want to check the actual voltage on your DIMMs when you have 1 and 4 installed so see if you have a load issue.

Also check that the MCH Heatsink clip is seated correctly. If it is lopsided that will for sure cause thermal issues.

You may have to get an additional CPU fan and mount it to the MCH.