4x1GB 1066 problem

[Lemsip]

I had a kit of:
TWIN2X2048-8500C5D PC2-8500 2GB Kit 5-5-5-15 240pin DIMM
Which has been working perfectly, however I bought the same kit again to upgrade to 4GB. Vista (Business 64bit) doesn't boot up when I use all four at 1066, so I have to run them at 800.

I have tested each module with MemTest and they work fine, but errors show up with all four.

I have seen topics with the same problem, saying that the voltage of the NB and RAM needs to be increased, but I couldn't find a clear answer so I would appreciate it if someone could tell me what needs increasing/by how much. Someone also told me that two twin kits don't work too well together - is this true?

My motherboard is an Asus Maximus Formula and my PSU is a Corsair HX620W.

Thanks in advance!

[dsvarups]

I have had a similar problem with my Asus Striker Extreme and 4 x 1gb Twinx 8500C5D

I was using 2 x 1gb that has been working fine for the past year. I bought another 2 x 1gb kit and when all four are installed I cant get past POST.

Tested the two new ones on there own and PC boots fine.

I have read on several forums that there are issues running 4 banks off at 800 and 1066.

[Yellowbeard]

"IF" your MOBO + chipset can handle 4 up at 1066, you typically do have to increase the memory controller aka NB, aka north bridge, aka SPP, voltages. They vary from board to board so, try slow small step increases over stock. Most likely the 1.4v to 1.5v range will do the trick.