Ok so basically I have seen many questions regarding latency across different servers so I decided to create a video demonstrating the latency from Myself->NA, Myself->EU, Myself->KR, Single Player aka Local, and "cracked" LAN. I am located on the East Coast (NY) of the USA. In addition to the video I added some "empirical" evidence/numbers.
Not sure if anyone has done all of these tests but here it is anyway.
Details:
These are the blizzard SC2 logon servers for each region, they may be a different entity than actual game servers, but I figure they are probably close in distance. There might be others that will automatically adjust for your location but I have no evidence or way to find this at the moment.
NA: 12.129.206.130 (us.logon.battle.net) located in CA, USA
EU: 213.248.127.130 (eu.logon.battle.net) located in Paris, France or UK? (Close enough regardless)
KR: 121.254.200.130 (kr.logon.battle.net) located in Seoul, Korea
Since I can't directly send ICMP packets (Ping) to each IP I did a speedtest.net ping to servers located in the same country/state.
The results for me are this (round-trip time):
NA: 70-80ms
EU: 85-120ms
KR: 210-242ms (Ouch)
Traceroutes:
+ Show Spoiler [NA] +
21 79 ms 78 ms 80 ms mdf001c7613r0003-gig-10-1.lax1.attens.net [12.129.193.242]
22 12.129.211.34 reports: Destination net unreachable.
22 12.129.211.34 reports: Destination net unreachable.
+ Show Spoiler [EU] +
8 285 ms 10 ms 18 ms nyk-bb2-link.telia.net [213.155.130.244]
9 110 ms 109 ms 112 ms ffm-bb2-link.telia.net [213.155.131.150]
10 116 ms 118 ms 117 ms ffm-b10-link.telia.net [80.91.251.124]
11 * * * Request timed out.
12 * * * Request timed out.
13 * * * Request timed out.
14 * * * Request timed out.
15 * * * Request timed out.
16 * * * Request timed out.
17 * * * Request timed out.
18 * * * Request timed out.
19 * * * Request timed out.
20 * * * Request timed out.
21 * * * Request timed out.
22 * * * Request timed out.
23 * * * Request timed out.
24 * * * Request timed out.
25 * * * Request timed out.
26 * * * Request timed out.
27 * * * Request timed out.
28 * * * Request timed out.
29 * * * Request timed out.
30 * * * Request timed out.
9 110 ms 109 ms 112 ms ffm-bb2-link.telia.net [213.155.131.150]
10 116 ms 118 ms 117 ms ffm-b10-link.telia.net [80.91.251.124]
11 * * * Request timed out.
12 * * * Request timed out.
13 * * * Request timed out.
14 * * * Request timed out.
15 * * * Request timed out.
16 * * * Request timed out.
17 * * * Request timed out.
18 * * * Request timed out.
19 * * * Request timed out.
20 * * * Request timed out.
21 * * * Request timed out.
22 * * * Request timed out.
23 * * * Request timed out.
24 * * * Request timed out.
25 * * * Request timed out.
26 * * * Request timed out.
27 * * * Request timed out.
28 * * * Request timed out.
29 * * * Request timed out.
30 * * * Request timed out.
+ Show Spoiler [KR] +
12 83 ms 80 ms 79 ms te0-0-0-5.ccr21.lax01.atlas.cogentco.com [154.54.0.221]
13 80 ms 88 ms 79 ms te9-1.ccr02.lax05.atlas.cogentco.com [154.54.44.130]
14 79 ms 81 ms 80 ms 38.104.84.42
15 190 ms 189 ms 189 ms gi12-0-0.cr2.nrt1.asianetcom.net [202.147.0.125]
16 225 ms 223 ms 226 ms po3-0.gw4.sel2.asianetcom.net [202.147.8.73]
17 210 ms 211 ms 210 ms LGT-0001.gw3.sel2.asianetcom.net [202.147.9.18]
18 232 ms 233 ms 243 ms 1.208.104.245
19 213 ms 213 ms 212 ms 211.233.55.126
20 212 ms 212 ms 210 ms 211.234.120.150
21 121.254.199.42 reports: Destination net unreachable.
13 80 ms 88 ms 79 ms te9-1.ccr02.lax05.atlas.cogentco.com [154.54.44.130]
14 79 ms 81 ms 80 ms 38.104.84.42
15 190 ms 189 ms 189 ms gi12-0-0.cr2.nrt1.asianetcom.net [202.147.0.125]
16 225 ms 223 ms 226 ms po3-0.gw4.sel2.asianetcom.net [202.147.8.73]
17 210 ms 211 ms 210 ms LGT-0001.gw3.sel2.asianetcom.net [202.147.9.18]
18 232 ms 233 ms 243 ms 1.208.104.245
19 213 ms 213 ms 212 ms 211.233.55.126
20 212 ms 212 ms 210 ms 211.234.120.150
21 121.254.199.42 reports: Destination net unreachable.
Video:
I created this video showing each server "test", it's quite bland :D
Timestamps:
NA - 00:00 to 02:08
EU - 02:08 to 04:30
KR - 04:30 to 07:54
Local - 07:54 to 10:32
Analysis:
So after I created the video I went back and did a frame by frame analysis to determine a rough latency. I used the rally point for most samples since it seemed to be the easiest to tell when the "reaction" happened. Also I am pretty sure there is no acceleration property of movement like a unit would have, slow ass Overseer, therefore setting the rally point should be as fast as possible.
So basically the first sign of the 4 greens arrows is where I set the "start" point frame. Shown Below
![[image loading]](http://i.imgur.com/h1hpN.png)
and I stopped on the first frame where the rally point changed. Shown Below
![[image loading]](http://i.imgur.com/69bbv.png)
+ Show Spoiler [Latency Samples] +
NA:
Click @ frame 2686
Reaction @ frame 2694
Delay = 8 frames
Click @ frame 2794
Reaction @ frame 2800
Delay = 6 frames
Click @ frame 2830
Reaction @ frame 2837
Delay = 7 frames
Click @ frame 2886
Reaction @ frame 2893
Delay = 7 frames
EU:
Click @ frame 5210
Reaction @ frame 5219
Delay = 9 frames
Click @ frame 5269
Reaction @ frame 5278
Delay = 9 frames
Click @ frame 5325
Reaction @ frame 5334
Delay = 9 frames
Click @ frame 5387
Reaction @ frame 5394
Delay = 9 frames
KR:
Click @ frame 11599
Reaction @ frame 11614
Delay = 15 frames
Click @ frame 11839
Reaction @ frame 11854
Delay = 15 frames
Click @ frame 11978
Reaction @ frame 11991
Delay = 13 frames
Click @ frame 12533
Reaction @ frame 12546
Delay = 13 frames
Local:
Click @ frame 15648
Reaction @ frame 15649
Delay = 1 frame
Click @ frame 15680
Reaction @ frame 15682
Delay = 2 frames
Click @ frame 15735
Reaction @ frame 15736
Delay = 1 frame
Click @ frame 15983
Reaction @ frame 15984
Delay = 1 frame
Cracked LAN (Separate Video Source):
Click @ frame 375
Reaction @ frame 382
Delay = 7 frame
Click @ frame 403
Reaction @ frame 411
Delay = 7 frame
Click @ frame 433
Reaction @ frame 442
Delay = 9 frame
Click @ frame 468
Reaction @ frame 475
Delay = 7 frame
Click @ frame 2686
Reaction @ frame 2694
Delay = 8 frames
Click @ frame 2794
Reaction @ frame 2800
Delay = 6 frames
Click @ frame 2830
Reaction @ frame 2837
Delay = 7 frames
Click @ frame 2886
Reaction @ frame 2893
Delay = 7 frames
EU:
Click @ frame 5210
Reaction @ frame 5219
Delay = 9 frames
Click @ frame 5269
Reaction @ frame 5278
Delay = 9 frames
Click @ frame 5325
Reaction @ frame 5334
Delay = 9 frames
Click @ frame 5387
Reaction @ frame 5394
Delay = 9 frames
KR:
Click @ frame 11599
Reaction @ frame 11614
Delay = 15 frames
Click @ frame 11839
Reaction @ frame 11854
Delay = 15 frames
Click @ frame 11978
Reaction @ frame 11991
Delay = 13 frames
Click @ frame 12533
Reaction @ frame 12546
Delay = 13 frames
Local:
Click @ frame 15648
Reaction @ frame 15649
Delay = 1 frame
Click @ frame 15680
Reaction @ frame 15682
Delay = 2 frames
Click @ frame 15735
Reaction @ frame 15736
Delay = 1 frame
Click @ frame 15983
Reaction @ frame 15984
Delay = 1 frame
Cracked LAN (Separate Video Source):
Click @ frame 375
Reaction @ frame 382
Delay = 7 frame
Click @ frame 403
Reaction @ frame 411
Delay = 7 frame
Click @ frame 433
Reaction @ frame 442
Delay = 9 frame
Click @ frame 468
Reaction @ frame 475
Delay = 7 frame
So here are the average frame delay:
NA: 7 frames
EU: 9 frames
KR: 14 frames
Local: ~1.25 frames (really don't have this precision but whatever)
Cracked LAN: ~7.5 frames

The video is 29.970 fps (frames per second) which means:
1 frame = (1sec / 29.970fps) * (1000ms / 1sec) = 33.37 ms (milliseconds), per frame
Conclusion:
For my location (USEast) to these servers, can be looked at as round-trip time:
NA: 233.59 ms avg
EU: 300.33 ms avg
KR: 467.18 ms avg
Local: 41.71 ms avg
Cracked LAN: 250.27 ms avg

Regarding "Cracked" LAN: My guess is that the code/server routine is not optimized at all. It does have to emulate the async aspect of the engine and probably does it as slow as possible to not throw desync type errors (no idea though, haven't analyzed the emu server enough). I have had to do the test with 2 SC2 clients open but it didn't seem to slow anything. This also doesn't mean that blizzard's implementation of LAN would be relativity "slow" as well or a modified version of this emu could have a lower latency or there is a hard minimum latency that cannot be reduced, however this is just speculation.
NA vs Local: 82.1% less latency than on NA
NA vs EU: 28.5% more latency than on NA
NA vs KR: 100% more latency than on NA
EU vs KR: 55% more latency than on EU
To explain the percentages let's say if you have 40ms vs 80ms on 2 different regions you probably couldn't tell the difference in a game but 80ms is actually 100% more laggy than 40ms. So you have to know at which point this time becomes noticeable.
Since I record all the samples in the same way looking at the actual delay number is probably not as useful as looking at the delta time between each region. Of course this might not be true if you're talking about really high latencies like 400ms+ which would feel much worse. Then you can say that this region is XX% times worse than your normal region.
Now there might be some errors created from recording at a low framerate and you could get an even more accurate number by increasing the recording framerate but I think these numbers are good enough.
Reading:
If you want to know why ICMP ping is not really as useful as this measurement read this.