I'm testing some DDR ram (one pc2100 and one pc2700) in a dell 4500s (1.8GHz Intel) and memtest hangs on the second test - Address Test, Own Address, No Cache. I've tested the sticks together and separately, and the same thing happens. The test just stops after a minute or two, with no error messages and loss of keyboard control. Tested one stick in a different computer, and it tests fine. It's a brand new memory chip. The Dell seems to run slower than I'd expect for a 1.8GHz with 384MB RAM. I especially noticed it when I was installing software from source packages - it went a lot slower than on my 1.2GHz Athlon with 500MB of pc133. Other than that, it seems to run ok. Here are my questions: Is it obviously the cpu? Is there any linux software that will test the cpu similar to what memtest does with memory? Any suggestions for diagnosing this problem? Thanks, Greg