At 6:33 AM -0400 7/15/06, Tom Horsley wrote: >On Sat, 2006-07-15 at 15:42 +1200, Hadders wrote: >> Tom Horsley wrote: >> > On Fri, 2006-07-14 at 21:52 -0400, Tom Horsley wrote: >> > >> > > Is there some known problem with > 2 gig of memory and >> > > the onboard usb with the x86_64 kernels? >> > > >> > >> > Sure enough, when I take out the extra gig of memory, >> > the scanner starts working and the boot time USB errors >> > go away. I guess I have a spare gig now (which is all >> > it really was before - I just thought I'd put it to >> > use :-). >> > >> > >> It's often been an historical fact that PC chipsets (not server class) >> often don't like addressing large amounts of memory and require >> particular DIMM configurations. >> They also get fussy about EXACT memory timings. Check your mainboard >> manual (asus are good for providing this as a download) for >> recommendations on what banks can be used to get to 3GB. > >Oh, I did all that. The memory has identical timing and >the i386 kernel as well as memtest86 has no problems, it >is only the x86_64 kernel that has USB troubles. I suspect >some sort of IOMMU nonsense, but the simplest fix is to >just leave only 2 gig in the machine in any case. Another test is to install the new memory in place of (some of) the old memory, so that there is 2 gig installed. If that works, then it's really likely to be the amount of memory; if it doesn't work, then it's probably the memory itself. ____________________________________________________________________ TonyN.:' <mailto:tonynelson@xxxxxxxxxxxxxxxxx> ' <http://www.georgeanelson.com/>
