failing memory

My computer has been acting flaky lately, crashing and a doing a few other things that suggested memory errors to me. So, i ran memtest86 and it was a bloodbath of errors.

i've never had memory fail before, so i would like some guidance. firstly, how can i be sure that it's the memory and not something like the motherboard's memory controller?(i don't have any spare memory to swap in and test with). secondly, i don't believe that all four dimms of my are bad. it's probably just one. how can i determine which one(s) are bad?

btw, the memory i'm referring to is 4 1GB sticks of OCZ ram running in dual channel mode on an evga nforce 780i mobo.

It may not be bad RAM or DIMM slot(s), but instead incorrectly set timings and / or DIMM voltage. Other things can also contribute to Memtest errors, including incorrectly set vNB, vSPP, and Vcore (Vcc). Post your system spec's in detail, including current Vdimm and RAM timings (including sub-timings). A direct link to your RAM would also be helpful.

ok, so i've tested each dimm individually and they're all fine. the errors only occur when i have two dimms in the same memory bank, which causes the motherboard to automatically access them in dual channel mode. i guess this probably means that the memory controller is the problem. does that sound right?

Yeap, assuming all settings are the same.

Or perhaps your motherboard cannot support as high a FSB with 4 sticks vs with 2 or 1, depending on how high your FSB is.

I heard nvidia chipsets don't like 4 sticks (take a larger hit on FSB cap compared to Intel chipsets).

well, i'm running it at the default fsb speed for a q6600 so it's like 266 mhz quad pumped and a 9x multiplier i think. i've been using these 4 sticks with this motherboard for about a year now with no problems. when i first built the box, i ran memtest86 overnight with all four sticks in it and there were no errors. for now, i'm just using 2 sticks of memory and i'm noticing a lot fewer crashes(zero) when i play games, etc. RMAing the motherboard is not going to be fun.