Slow apt-get after adding i386 architecture

You have to be aware that when adding i386 as additional architecture, the package management has to download twice the amount of information about the repository contents. This may take twice the time than before.
But for each i386 package the download should take as long as the equivalent and64 package.

If you experience something different, then please past the output that you get for the commands

uname -a
lsb_release -crid
dpkg --print-architecture
dpkg --print-foreign-architectures
sudo apt-get update

uname -a:
Linux 4.13.0-16-generic #19-Ubuntu SMP Wed Oct 11 18:35:14 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

lsb_release -crid:
Distributor ID: Ubuntu
Description: Ubuntu 17.10
Release: 17.10
Codename: artful

dpkg --print-architecture:
amd64

dpkg --print-foreign-architectures
i386

sudo apt-get update:
Ign:1 http://dl.google.com/linux/chrome/deb stable InRelease
Obj:2 http://dl.google.com/linux/chrome/deb stable Release
Obj:4 http://sv.archive.ubuntu.com/ubuntu artful InRelease
Obj:5 http://repository.spotify.com stable InRelease
Des:6 http://security.ubuntu.com/ubuntu artful-security InRelease [70.3 kB]
Des:7 http://sv.archive.ubuntu.com/ubuntu artful-updates InRelease [76.7 kB]
Obj:8 http://sv.archive.ubuntu.com/ubuntu artful-backports InRelease
Descargados 147 kB en 1s (120 kB/s)
Leyendo lista de paquetes... Hecho

for example, if i install virtualbox (sudo apt-get install virtualbox) the process starts as expected but, it hangs sometimes in "waiting for headers".

i have another box, almos same setings (no i386 arch) and i download the same package and it is faster.

uname -a:
Linux 4.13.0-16-generic #19-Ubuntu SMP Wed Oct 11 18:35:14 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

lsb_release -crid:
Distributor ID: Ubuntu
Description: Ubuntu 17.10
Release: 17.10
Codename: artful

dpkg --print-architecture:
amd64

dpkg --print-foreign-architectures
i386

sudo apt-get update:
Ign:1 http://dl.google.com/linux/chrome/deb stable InRelease
Obj:2 http://dl.google.com/linux/chrome/deb stable Release
Obj:4 http://sv.archive.ubuntu.com/ubuntu artful InRelease
Obj:5 http://repository.spotify.com stable InRelease
Des:6 http://security.ubuntu.com/ubuntu artful-security InRelease [70.3 kB]
Des:7 http://sv.archive.ubuntu.com/ubuntu artful-updates InRelease [76.7 kB]
Obj:8 http://sv.archive.ubuntu.com/ubuntu artful-backports InRelease
Descargados 147 kB en 1s (120 kB/s)
Leyendo lista de paquetes... Hecho

for example, if i install virtualbox (sudo apt-get install virtualbox) the process starts as expected but, it hangs sometimes in "waiting for headers".

i have another box, almos same setings (no i386 arch) and i download the same package and it is faster.

I cannot imagine that a longer delay "waiting for headers" could be caused by having i386 defined as additional architecture. There has to be another cause.

Do you use the same repository servers on these two systems?

ive changed servers from El Savlador to EEUU and it is faster. thanks