USB 4X DVD Recording

Original 4X Firmware

$ time growisofs -speed=40 -Z /dev/sr0=tmp.iso

Executing 'builtin_dd if=tmp.iso of=/dev/sr0 obs=32k seek=0'
/dev/sr0: "Current Write Speed" is 4.1x1385KBps.
         0/4396800000 ( 0.0%) @0x, remaining ??:??
         0/4396800000 ( 0.0%) @0x, remaining ??:??
         0/4396800000 ( 0.0%) @0x, remaining ??:??
         0/4396800000 ( 0.0%) @0x, remaining ??:??
         0/4396800000 ( 0.0%) @0x, remaining ??:??
         0/4396800000 ( 0.0%) @0x, remaining ??:??
   6553600/4396800000 ( 0.1%) @1.4x, remaining 279:07
  24707072/4396800000 ( 0.6%) @3.8x, remaining 82:34
  42860544/4396800000 ( 1.0%) @3.8x, remaining 54:10
.....
4350967808/4396800000 (99.0%) @3.9x, remaining 0:08
4369580032/4396800000 (99.4%) @3.9x, remaining 0:05
4388159488/4396800000 (99.8%) @3.9x, remaining 0:01
builtin_dd: 2146880*2KB out @ average 3.8x1385KBps
/dev/sr0: flushing cache
/dev/sr0: closing track
/dev/sr0: closing session
/dev/sr0: reloading tray

real    14m8.927s
user    0m0.179s
sys     0m10.696s

Firmware patched from 4X to 8X
Imation 8X DVD+R disc
Total time reduced from 14m to 8m

$ time growisofs -speed=40 -Z /dev/sr0=tmp.iso

Executing 'builtin_dd if=tmp.iso of=/dev/sr0 obs=32k seek=0'
/dev/sr0: "Current Write Speed" is 8.2x1385KBps.
         0/4396800000 ( 0.0%) @0x, remaining ??:??
   7045120/4396800000 ( 0.2%) @1.5x, remaining 103:50
  25231360/4396800000 ( 0.6%) @3.8x, remaining 40:25
          .......
 518127616/4396800000 (11.8%) @3.9x, remaining 12:58
 536444928/4396800000 (12.2%) @3.9x, remaining 12:49
 539033600/4396800000 (12.3%) @0.5x, remaining 13:07
 567443456/4396800000 *(12.9%) @6.0x*, remaining 12:49
          .......
1592819712/4396800000 (36.2%) @6.0x, remaining 6:51
1612021760/4396800000 (36.7%) @4.1x, remaining 6:49
1628864512/4396800000 (37.0%) @3.6x, remaining 6:47
1665269760/4396800000 *(37.9%) @7.7x*, remaining 6:40
          .......
4339859456/4396800000 (98.7%) @7.8x, remaining 0:06
4376821760/4396800000 (99.5%) @7.8x, remaining 0:02
builtin_dd: 2146880*2KB out @ average 6.3x1385KBps
/dev/sr0: flushing cache
/dev/sr0: closing track
/dev/sr0: closing session
/dev/sr0: reloading tray

real    8m42.522s
user    0m0.166s
sys     0m10.281s

3rd burning again on 8X imation dvd+r disc
Unsteady burning speed ...

$ time growisofs -speed=40 -Z /dev/sr0=tmp.iso

Executing 'builtin_dd if=tmp.iso of=/dev/sr0 obs=32k seek=0'
/dev/sr0: "Current Write Speed" is 8.2x1385KBps.
         0/4534800384 ( 0.0%) @0x, remaining ??:??
   5636096/4534800384 ( 0.1%) @1.2x, remaining 133:55
  23789568/4534800384 ( 0.5%) @3.8x, remaining 44:14
....
 534478848/4534800384 (11.8%) @3.9x, remaining 13:20
 538247168/4534800384 (11.9%) @0.8x, remaining 13:36
 564330496/4534800384 (*12.4%) @5.5x*, remaining 13:22
 592740352/4534800384 (13.1%) @6.0x, remaining 12:58
 621117440/4534800384 (13.7%) @6.0x, remaining 12:36
....
1589313536/4534800384 (35.0%) @6.0x, remaining 7:13
1611988992/4534800384 (35.5%) @4.8x, remaining 7:09
1624145920/4534800384 (35.8%) @2.6x, remaining 7:10
1660518400/4534800384 *(36.6%) @7.7x*, remaining 7:02
1696890880/4534800384 (37.4%) @7.7x, remaining 6:53
....
4509630464/4534800384 (99.4%) @7.8x, remaining 0:02
builtin_dd: 2214272*2KB out @ average 6.3x1385KBps
/dev/sr0: flushing cache
/dev/sr0: closing track
/dev/sr0: closing session
/dev/sr0: reloading tray

real    8m59.423s
user    0m0.173s
sys     0m10.775s