I have a Samsung X360 laptop. It comes with 3gb ram installed. I have Ubuntu 15 64bit installed. I upgraded the 1gb stick to a 2gb stick. After upgrading from 3gb ram to 4gb ram:
- Ubuntu 15 amd64 will not load and keeps rebooting over and over during boot (I never see splash screen, only boot menu).
- Ubuntu amd64 live from USB will do the same.
- Ubuntu 15 live i386 will boot and show all 4gb of ram.
I ran memtest and it passes all 4gb, I booted on just the new 2gig stick and Ubuntu amd64 loads, and it loads with the 1 gig stick giving 3gig total like with the original memory. Boots into amd64 without issue.
I only have issues booting into Ubuntu amd64 with 4gig of ram installed and not when running the i386 version. I also booted off of the windows 7 install DVD and it booted with no issue with the 4gigs installed,
I also tried Ubuntu versions 15, 14, and 12 in the amd64 versions and they all will not boot with the 4gig of ram installed but will with only 3gig. again 32bit versions load without issue with the entire 4gig installed.
The laptop comes with 3gig of Samsung memory 1x 2gb, and 1x 1gb. I purchased a new stick from newegg; Gskills 1x 2gb, this stick alone and also paired with the 1gb Samsung stick will boot Ubuntu 64bit?
2 Answers
Take out all of the original RAM, boot into memtest, its possible the new chip is bad. As to why remove the original RAM, it is simply a time saver as you know that it, the originsl RAM is good.
Maybe check if You can flash bios of this laptop to the latest, also it seems the laptop works with 386 architecture but not with x64 as for properly detected memory RAM (it was also same with Windows) but normally it should be like 386 system detects max 3GB RAM while x64 can see more capacity. Maybe check with another RAM sticks just to ensure it's all ok with hardware. Your CPU is most probably x64 architecture so it's kinda weird it can't detect all RAM under x64 system.
