I have been running KDE 4.6 and openSuSE 11.4 for several months, on a lenovo W510 laptop. I’ve ironed out every hardware/software issue except for the following problem, which crops up frequently.
When running an application that uses a lot of RAM (e.g. mathematica or a program called visual molecular dynamics or VMD), the desktop locks up almost completely when the RAM gets close to full and the swap file starts filling up. I have 4GB 1333mHz ram and an 8GB swap file (located on my extended partition along with /home and root). For comparison, I can perform identical tasks in windows7 (some sluggishness when the RAM fills up, but I can still interact with the windows). I understand that the swap file is much slower than RAM, but sometimes it takes me several minutes just to close the offending program. Given that windows shows much better performance with the same task and nearly full RAM, I suspect something is wrong.
I have a desktop (i7-2600, NVidia 460) with the exact same software setup, and it has the same exact problem. I assume that even a quad-core laptop shouldn’t stall like this when the memory gets full. Please let me know if anybody has any suggestions for diagnosing this problem.