Thanks a lot for all infos right now. I will try a PAE Kernel next week. best regards
On 08.08.2018 01:48, Michael Stone wrote: > On Wed, Aug 08, 2018 at 12:25:14AM +0200, deloptes wrote: >> Pascal Hambourg wrote: >> >>> But you need a >>> 686-pae or amd64 kernel to use RAM beyond 4 GiB, as Michael pointed out. >> >> but he has 3GB and machine sees only 2 - is it because kernel is not pae? >> I was thinking that 686 system can see (and use) around 3GB and with some >> trick above, but in case of 4GB it did not make any sense from technical >> point of view, because much of it is lost for reserved mapping tables >> (AFAIR). So mem is optimal on that machine, but why it can see only 2 >> of 3? >> Is one GB shared with graphics controller? > > Short answer is yes, all 3GB should show up. Why isn't it? No idea. > dmesg would help, lscpu would help, knowing whether all 3GB is seen in > the system's bios would help. PAE kernel might help, and performance > with 3GB RAM and no PAE will be really terrible anyway. The only reason > to run a non-PAE kernel would be if the CPU is too old to support PAE. > (In which case there may be any number of reasons why things are flaky > on 15 or 20 year old hardware.) > > If this is a really, really old machine and just an experiment, carry > on. With reasonably modern hardware the right answer for >1G RAM is an > amd64 kernel. If you have an (unusual) need to run an i386 userspace you > can install the amd64 kernel on i386 system. All of the options for > running >1G on 32 bit kernel have pretty severe performance impact. > It's possible that memory has been reserved for an on-board GPU, but I'm > having trouble wrapping my head around the idea of a machine that > memory-limited using a gig of video memory. dmesg would help understand > that. I lean toward suspecting the chipset just doesn't support >2G, but > knowing what the BIOS reports would clear that up. > > Mike Stone >