And, for comparison, the latest server I installed in our colo on the host system (with Corsair M500 SSDs):

    [root@srv3 joe]# dd if=/dev/zero of=~/test.bin bs=1M  count=1000
    1000+0 records in
    1000+0 records out
    1048576000 bytes (1.0 GB) copied, 0.310283 s, 3.4 GB/s

And, from within a VM on the same machine (running KVM with an LVM volume):

    [root@joe2 ~]# dd if=/dev/zero of=~/test.bin bs=1M count=1000
    1000+0 records in
    1000+0 records out
    1048576000 bytes (1.0 GB) copied, 0.967834 s, 1.1 GB/s

So, Atlantic.net isn't too bad, I guess. My newest system isn't very heavily loaded yet; only has three VMs and a couple dozen websites on it.