Should I ask to move datacentres?

I'm in the UK, and noticed slightly better ping times when I moved to a Linode in Atlanta from (I think) Dallas. In terms of responsiveness for web and ssh, I didn't really notice much difference, though.

My Atlanta Linode is on 64.22.124.184, if you want to see what times to it are like.

There's a thread with links to copies of a large file hosted in each data center. You could also ping or traceroute the hosts, or whatever.

Download File Speed Test

The infamous NTL (now Virgin Media*) Leeds proxy heavily limits http transfers of large files so the large file test is a bit useless, but the traceroutes are interesting

Fremont

traceroute to technomancer.co.uk (64.71.152.131), 30 hops max, 40 byte packets
 1  192.168.2.1 (192.168.2.1)  2.136 ms  2.057 ms  3.910 ms
 2  10.231.212.1 (10.231.212.1)  10.720 ms  11.122 ms  11.351 ms
 3  leed-t2cam1-a-ge91.inet.ntl.com (80.0.54.153)  13.495 ms  13.717 ms  17.568 ms
 4  seac-dpim1-1-coc-1-gw.service.virginmedia.net (80.0.50.146)  19.983 ms  18.537 ms  18.193 ms
 5  lee-bb-a-so-230-0.inet.ntl.com (213.105.175.65)  18.754 ms  18.802 ms  20.590 ms
 6  nth-bb-b-so-100-0.inet.ntl.com (62.253.185.101)  20.654 ms  16.769 ms  16.860 ms
 7  tele-ic-1-as0-0.inet.ntl.com (62.253.184.2)  16.696 ms  17.199 ms  17.356 ms
 8  gsr12012.lon.he.net (195.66.224.21)  16.839 ms  17.402 ms  22.035 ms
 9  10gigabitethernet2-3.core1.nyc4.he.net (72.52.92.77)  89.328 ms  89.513 ms  83.532 ms
10  10gigabitethernet3-1.core1.sjc2.he.net (72.52.92.25)  163.581 ms  166.892 ms  167.296 ms
11  10gigabitethernet1-1.core1.fmt1.he.net (72.52.92.109)  167.610 ms  168.902 ms  169.097 ms
12  li14-131.members.linode.com (64.71.152.131)  167.329 ms  164.543 ms  164.795 ms

Atlanta

traceroute to 64.22.124.184 (64.22.124.184), 30 hops max, 40 byte packets
 1  192.168.2.1 (192.168.2.1)  2.304 ms  2.106 ms  4.386 ms
 2  10.231.212.1 (10.231.212.1)  40.085 ms  40.393 ms  40.665 ms
 3  leed-t2cam1-b-ge91.inet.ntl.com (80.0.55.153)  40.861 ms  41.057 ms  41.341 ms
 4  leed-t3core-1b-ge-115-0.inet.ntl.com (195.182.179.241)  41.437 ms  42.833 ms  43.329 ms
 5  lee-bb-b-so-020-0.inet.ntl.com (213.105.175.69)  43.525 ms  43.724 ms  43.904 ms
 6  nth-bb-a-so-030-0.inet.ntl.com (213.105.175.133)  46.485 ms  21.535 ms  13.163 ms
 7  212.43.162.230 (212.43.162.230)  37.590 ms  37.919 ms  38.192 ms
 8  cr02.frf02.pccwbtn.net (80.81.192.50)  38.386 ms  38.572 ms  38.803 ms
 9  gnax.ge2-13.br01.atl01.pccwbtn.net (63.216.31.130)  132.427 ms  132.812 ms  132.877 ms
10  atl-core-a-g3-1.gnax.net (63.247.69.177)  131.460 ms  135.460 ms  135.800 ms
11  l3-atl-18.gnax.net (209.51.131.74)  149.957 ms  133.698 ms  133.834 ms
12  splinter.brokenbottle.net (64.22.124.184)  133.824 ms  129.441 ms  143.790 ms

It's the same number of hops despite being routed completely differently. Lets ping a little.

--- technomancer.co.uk ping statistics ---
40 packets transmitted, 40 received, 0% packet loss, time 38999ms
rtt min/avg/max/mdev = 161.370/167.056/192.970/7.243 ms

Atlanta

--- 64.22.124.184 ping statistics ---
40 packets transmitted, 40 received, 0% packet loss, time 39004ms
rtt min/avg/max/mdev = 126.157/128.749/148.592/4.488 ms

So we're looking at 38ms +/- 10ms better off. Not huge but is it noticeable? I suppose I should work out the average page load time on hot and cold cache samples. But off the top of my head, a page on leedsrocksoc.co.uk (drupal+lots of avatars) might be >40 GET requests on a cold cache on a busy page and maybe 4 on a very warm cache, but there may be parallel connections going on. Best guestimate maybe between 0.1 and 1 second per page. That's comparable to the difference between default configs for lighttpd and apache (although a well tuned apache is nearly as quick for me but that's off topic).

I think I'm going to ask the rest of the site teams this one. I think we're going to have some scheduled downtime during the summer when the sites are pretty much dead and there are major site upgrades to be rolled out.