First I had 4x2gb corsair and my system was running flawlessly.
Then I bought myself 4x4GB Corsair 1600Mhz 9-9-9-24 Vengeance DL9 (LP), and when I put all 4 modules in (thus removing all four old memory sticks), linux "free" reports I have 16gb ram, so that's fine, but the whole system froze a few times, and I had to reboot. Didn't find anything in the logs.
So I ran memtest86+ v4.20 with all 4 modules in, and it reported an error, but when I started testing each individual module one by one (3 passes), no errors. Do I need to run more passes or could there be something else wrong? Is it possible that a memory slot is broken? It doesn't make sense because my pc worked with the 4x2gb sticks.
Please advice what to do.