Some further Block Compression tests results that compare
performance when network latency is added to the mix.
Running two nodes, windows 7, compressionlevel=6, syncing the first
200000 blocks from one node to another. Running on a highspeed
wireless LAN with no connections to the outside world.
Network latency was added by using Netbalancer to induce the 30ms
and 60ms latencies.
From the data not only are bandwidth savings seen but also a small
performance savings as well. However, the overall the value in
compressing blocks appears to be in terms of saving bandwidth.
I was also surprised to see that there was no real difference in
performance when no latency was present; apparently the time it
takes to compress is about equal to the performance savings in such
a situation.
The following results compare the tests in terms of how long it
takes to sync the blockchain, compressed vs uncompressed and with
varying latencies.
uncmp = uncompressed
cmp = compressed
| num
blocks sync'd |
uncmp (secs) |
cmp (secs) |
uncmp 30ms (secs) |
cmp 30ms (secs) |
uncmp 60ms (secs) |
cmp 60ms (secs) |
| 10000 |
264 |
269 |
265 |
257 |
274 |
275 |
| 20000 |
482 |
492 |
479 |
467 |
499 |
497 |
| 30000 |
703 |
717 |
693 |
676 |
724 |
724 |
| 40000 |
918 |
939 |
902 |
886 |
947 |
944 |
| 50000 |
1140 |
1157 |
1114 |
1094 |
1171 |
1167 |
| 60000 |
1362 |
1380 |
1329 |
1310 |
1400 |
1395 |
| 70000 |
1583 |
1597 |
1547 |
1526 |
1637 |
1627 |
| 80000 |
1810 |
1817 |
1767 |
1745 |
1872 |
1862 |
| 90000 |
2031 |
2036 |
1985 |
1958 |
2109 |
2098 |
| 100000 |
2257 |
2260 |
2223 |
2184 |
2385 |
2355 |
| 110000 |
2553 |
2486 |
2478 |
2422 |
2755 |
2696 |
| 120000 |
2800 |
2724 |
2849 |
2771 |
3345 |
3254 |
| 130000 |
3078 |
2994 |
3356 |
3257 |
4125 |
4006 |
| 140000 |
3442 |
3365 |
3979 |
3870 |
5032 |
4904 |
| 150000 |
3803 |
3729 |
4586 |
4464 |
5928 |
5797 |
| 160000 |
4148 |
4075 |
5168 |
5034 |
6801 |
6661 |
| 170000 |
4509 |
4479 |
5768 |
5619 |
7711 |
7557 |
| 180000 |
4947 |
4924 |
6389 |
6227 |
8653 |
8479 |
| 190000 |
5858 |
5855 |
7302 |
7107 |
9768 |
9566 |
| 200000 |
6980 |
6969 |
8469 |
8220 |
10944 |
10724 |