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TS3 User Manual
11S-3000M
page 107
When the PC is Too Busy:
Referring to Table 10-3, you will notice th a t for several of
the transfers there are missing frames and packets. These
were downloads of only 188 frames, which should be
very easy considering that FasMotion r eserved 250
bu ff ers--more than enough to bu ff er the enti r e transfer.
The Min (minimum bu ff ers) never got close to the
Backoff numbe r , so the Fas M otion n e ver got a chance to
slow the camera down before it started missing frames.
To understand what happened here, it is helpful to look
at the performance tab in Task Manager. Notice in Figure
10-12 that the “Free” memory has gone to 0. This means
that, having no more physical memory, the system is
going to slow down. It will not be able to service the
application p r operly.
What is happening here is that the system is very busy.
To create this example, the computer used had about a
dozen applications open.
It is common to have a lot of applications and se
r vices
running “in the background” on a computer. In order
to get consistent high-speed file t r ansfers from Fas M otion it is v ery important to have as little
else running on the PC as possible.
Note: In each instance on the table, all of the frames were successfully saved as the
system automati c ally retrieves any “missed frames” at the end of the download.
Use Jumbo Packets!:
Referring to Table 10-4, using Jumbo Packets (sometimes c alled Jumbo Frames) can make a big
di ff erence. You may find th a t a larger packet delay is required with Jumbo Frames, but because
the packets are bigger, there are fewer of them, and fewer delays as well.
In this example there was about a 3x improvement in transfer rate simply by using Jumbo Packets.
Figure 10-12: Memory Usage in Task Manager
Duration
h:m:s:dec
Bytes Speed
MB/s
Miss-
Frames
ROI Good-
Frames
Pkt-
Size
MissPkts PktDly Bu ff er Backo ff Min Drv Ext
0:0:6:650 26573616 4.22376 0 1280x1024 188 1500 0 180 250 125 236 C: AVI
0:0:33:468 246528160 7.12447 0 1280x1024 188 1500 0 180 250 125 247 C: DNG
0:1:40:407 739256608 7.0501 5 1280x1024 188 1500 9708 180 250 125 248 C: BMP
0:0:7:611 26563368 3.61897 3 1280x1024 188 1500 280 180 250 125 216 C: JPG
0:1:41:698 739300976 6.98072 5 1280x1024 188 1500 5354 180 250 125 247 C: TIF
0:0:33:951 246468752 7.12276 1 1280x1024 188 1500 578 180 250 125 247 C: TIF
Table 10-3: Missing Frames on a Busy System
Duration
h:m:s:dec
Bytes Speed
MB/s
Miss-
Frames
ROI Good-
Frames
Pkt-
Size
MissPkts PktDly Bu ff er Backo ff Min Drv Ext
0:0:28:484 484259096 16.4938 0 1280x960 394 1500 0 40 200 100 196 F: ti
0:0:28:156 484259096 16.4938 0 1280x960 394 1500 0 40 200 100 195 F: ti
0:0:9:438 484259096 51.3139 0 1280x960 394 9000 0 40 200 100 182 F: ti
0:0:26:734 1317578048 48.3285 0 1280x960 1072 9000 0 40 200 100 105 F: ti
0:0:47:203 2443418992 49.5793 0 1280x960 1988 9000 0 40 200 100 190 F: ti
Table 10-4: Benefit from Jumbo Packets