Meltdown and Spectre and thoughts on buying a new computer

[Ralf Mardorf]

On Fri, 2 Mar 2018 20:59:31 -0500, Bill wrote:
>It is about time to think about buying a new computer but I am
>concerned about Meltdown and Spectre.

Hi,

consider if Meltdown and Spectre have got substantial impact on
security for your kind of computer usage. I'm waitig for a
heavy drop in prices and then will replace my 6.60.3 Intel Celeron
G1840 by a multi-core Pentium.

I've got the impression that the performance of the OS I'm running in a
qcow VM from a SSD heavily slowes down with page-table isolation
enabled, but the reason for this might be another issue, I didn't make
valid tests. Apart from this, I never run a real-time audio session
with Meltdown and Spectre mitigations.

My computer is a digital audio workstation mainly aimed for real-time
audio sessions, so I don't have that much concerns regarding security.

My bootloader provides entries to boot with page-table isolation
disabled:

[rocketmouse at archlinux ~]$ grep nopti /boot/syslinux/syslinux.cfg | grep AP
    APPEND root=LABEL=archlinux ro threadirqs nopti
    APPEND root=LABEL=archlinux ro nopti
[rocketmouse at archlinux ~]$ grep nokaiser /boot/syslinux/syslinux.cfg | grep AP
    APPEND root=LABEL=moonstudio ro nokaiser

"nopti" is for the newer Arch Linux kernels and "nokaiser" for an Ubuntu
kernel, but as already pointed out, I still didn't make valid
comparisons.

The long and the short of it, I'm willing to disable Meltdown
mitigation, if the VM and especially if the DSP load for real-time audio
usage would benefit from less good Internet security.

For Internet server usage, better go with an AMD, since those CPUs are
not that much affected as Intel CPUs are. For real-time audio sessions
my experiences with Intel are better than with AMD, so I don't care too
much about Meltdown and Spectre.

Regards,
Ralf