4Gig memory problem

[Cluelessoldtimer]

I built two nearly identical rigs back in May

Intel Duo 6600 2.4Ghz Conroe
Gigabyte GA-965P-DS3 (rev 1.3)
2 gigs Wintec DDR2 800 (1 gig sticks)
PNY 8800 GTS 320MB
Seagate Barracuda 320G
Roswill 600v power supply
Asus 18X DVD burners

Both running Windows Vista Business 64-Bit (the only difference between the computers is that one has two of the barracuda harddrives in a raid 0 array for data backup).

Everything was fine. Then I bumped the memory on both computers about 4 weeks ago to 4 gigs with the same type of memory. The computers became somewhat unstable at bootup, sometimes restarting themselves once or twice before getting up and running. But once booted up they ran fine. The restarting problem has been getting worse on both computers, now one computer will not boot at all with 4 gigs installed. Any of the sticks in a 2 gig configuration works fine, which seems to indicate that it isn't a case of a bad memory stick.

Any ideas? Just seems strange as heck that I have the same problem on both rigs (although worse on one than the other).

 

[montag451]

Maybe you need to bump the voltage to the RAM up a little

 

[mechBgon]

See if it'll run memtest86 (free download) long enough for a pass or two. Any errors?

4-module configurations can be tougher to keep stable than 2-module configurations; it might help to relax the RAM timings in the BIOS and raise the memory voltage just a bit. If memtest86 does give you errors, you can make some adjustments and then test again to see what the result is.

 

[Cluelessoldtimer]

Thanks guys. Although I've built computers for a long time, I have never done any overclocking what so ever, so I'm sure these are total newbie questions...

I can find the setting to up the DIMM voltage easily. It appears to be in +.1V increments, how high should I have to (or dare I) go?

The only other BIOS setting I see in my manual is the System memory multiplier. I'm running a FSB of 1066 (4x266?) and my options range from host clock x 2 up to x 4+. Again, what should I start with?

Am I missing any other BIOS memory settings?


Thanks again!

 

[mechBgon]

On that screen, I believe CTRL F1 brings up the detailed settings menu where you could relax the RAM timings. The manual I downloaded doesn't show it, so I don't know precisely what you'll find there. In general, if you raise the numbers, you're relaxing the timings. sample pic from an Asus motherboard If I had problems with running four modules on this one, I'd try scooting the timings up from 4-4-4-12-16 (1T) to new settings of 5-5-5-12-16 (2T) and see if that helped. The (1T) changing to (2T) might be a big help by itself, this is generally called the Command Rate.

For voltage boosting, 1.8 volts is the "stock" voltage, so try 1.9V and then do a reality test and/or Memtest86 to see what the effect is. That shouldn't hurt anything.