Hi guys, I built a computer with DH55TC, I3 560, a pair of 2GB Kingston PC3-10700 (667 MHz) and a 2GB SATA3 disk. So far, it runs fine under Windows 7 64 bit and does what it should. Then I went on to increase the memory to please Photoshop with it. I bought two more Kingston PC3-10700 (667 MHz) modules, this time with 4 GB each. Now: I can use these RAMs in whatever combination only up to 8 GB. Whenever I increase the size over 8 GB (i.e., 10 or 12, no matter which slots), the system boots and works, but extremely slow. Win 7 boot takes around 10 minutes. In tests with memtest86+ the combined memory does not result in a memory error. But: Whenever the combined size is over 8GB the last part of each test runs extremely slow. I mean the following: Memtest shows which part it is testing, 1 to 2048, 2048 to 4096 and so on. All runs are fast, besides the last one, whenever this is beyond 8 GB. Has anybody an explanation for this? Has it to do with memory mapping? For the tests I used the usual "e820" method and it always shows the exact size. What is wrong with this mainboard?