Hello, Am having two strange problems that are starting to eerk me with this (relatively new) computer, running Debian wheezy: 1. If I boot anything later then 3.12 kernel, I don't get any display. As in the monitors display black. No cursors of any sort. Changing to a virtual console doesn't help. Booting in rescue mode doesn't help (I think this rules out X-Windows being a problem). If I go back to the 3.12 kernel, everything works perfectly. I also tried plugging monitors into alternative ports just in case it is going to the wrong place, but get nothing - in any case, under 3.12 the computer seems pretty good at automatically working out what ports are active under X-Windows. 01:00.0 VGA compatible controller: NVIDIA Corporation G96 [GeForce 9500 GT] (rev a1) Am currently using the non-free nvidia drivers. Had exactly the same symptoms when I installed the latest kernel without the non-free nvidia kernel modules. I think the problem is occurring before X starts. Computer seems to be up and running, and responsive to crl+alt+del despite not having a display. 2. There seems to be some weird performance problem. e.g. save a 2 kilobyte file in vim, and the computer can completely freeze (all other windows, including xterms, stop responding to user input) for, say 30 seconds, while it is writing that file. Chromium takes ages to load with several tabs, and pages can fail to start properly while it is doing so. Computer has 16GB RAM and is not using any swap. It has 11GB of buffer/cache space: total used free shared buffers cached Mem: 15G 13G 2.1G 0B 1.1G 7.9G -/+ buffers/cache: 4.6G 11G Swap: 3.8G 0B 3.8G Problems occurred before starting chromium, previously I wondered if it was chromium's fault. This is moving disk + RAID1 + LVM + ext4. Bonnie++ results seem to be pretty good, better in fact then my work computer, which doesn't suffer from similar problems. Writing a byte at a time...done Writing intelligently...done Rewriting...done Reading a byte at a time...done Reading intelligently...done start 'em...done...done...done...done...done... Create files in sequential order...done. Stat files in sequential order...done. Delete files in sequential order...done. Create files in random order...done. Stat files in random order...done. Delete files in random order...done. Version 1.96 ------Sequential Output------ --Sequential Input- --Random- Concurrency 1 -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks-- Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP falidae 31904M 1228 94 107313 4 47471 2 +++++ +++ 137886 3 441.8 2 Latency 19141us 12435ms 251ms 19913us 88073us 283ms Version 1.96 ------Sequential Create------ --------Random Create-------- falidae -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete-- files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP 16 +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++ Latency 36us 223us 226us 36us 10us 24us 1.96,1.96,falidae,1,1404290654,31904M,,1228,94,107313,4,47471,2,+++++,+++,137886,3,441.8,2,16,,,,,+++++,+++,+++++,+++,+++++,+++,+++++,+++,+++++,+++,+++++,+++,19141us,12435ms,251ms,19913us,88073us,283ms,36us,223us,226us,36us,10us,24us I am currently working on a new theory that the performance problems only occur when the computer is cold and first turned on. I think I have seen evidence to disprove this, but guess I should run bonnie++ as soon as I turn the computer on, just to be sure. Any other ideas? Thanks -- Brian May <brian@microcomaustralia.com.au>