Well I just found something very weird yesterday. I bought my Gskill HZ DDR2 800MHz ram about 2 summers ago when I put my computer together. Currently it has a ASUS P5K-E MB with E8400 CPU, GSkill HZ 2GB (1x 1GB sticks) and a EVGA 8800 GTX. So I got a deal from a friend for another 2GB (1x 1GB sticks) to get me up to 4GB total. Well, with this I decided to go and get another 8800GTX which I also found for a great deal to do SLI. Only thing was my MB is a Crossfire board so I decided to pick up an EVGA nForce 750i SLI Desktop Board so I can do SLI. Well, I was putting the system together for its first run last night when I tried to boot everything on 4GBs of ram. I got a C1 error from the MB's post code which is "Base Memory Detect Error". So I took out 2 of the sticks and tried to run 2GB in dual channel. Well, I got the same error. I ended up looking closely at the memory and I saw that 1 of the 1GB sticks had a black heat spreader like they are supposed to but had a green memory card where are all the others have a black card with black heat spreader. I checked the serial numbers from the 2 sticks I got from a friend and they matched except for the last digit, which makes sense. The 2 I had previously in my system had completely different serial codes, and one said F2-6400PHU2-2GBHZ and the other said F2-6400PHU1 - 1GBHZ. So are these two different size memory or just from a different set?? For some reason the two different sticks worked on my ASUS P5K-E MB for 2 years. When I put in the HZ Sticks with the black ram color into the new EVGA MB, the system boots up and shows 3GB memory. But when I try to put in the 1GB stick that is different the system freezes on C1 post code. How is this possible? Why would it work on one MB and not the other? Also, I tested all 4 sticks by putting them in my ASUS MB and the computer booted into windows and showed 4GB of total memory. Would GSkill believe me if I told them this is what happened? Or should I call Newegg and tell them they gave me 2 different sticks when they were supposed to be paired?
Sorry for the long post! I thought I was going crazy last night when I figured this out.