Opened 13 years ago

Last modified 13 years ago

#3501 closed Bug report

overload CPU when download files

Reported by: z80user Owned by:
Priority: normal Component: FileZilla Client
Keywords: Cc: z80user, Alexander Schuch, Tim Kosse
Component version: Operating system type:
Operating system version:


If put a file in server, the CPU load is low, but when get, the CPU load is over 66% of one core.

Core2Duo 2.16GHz 1GB/Ram, Tred @100Mbps over 11.5MB/s

Change History (7)

comment:1 by Alexander Schuch, 13 years ago

Which version of FileZilla are you using? Which platform are you using? Do you use FTP, SFTP, FTPS, FTPES, etc.? What does 'Tred @100Mbps over 11.5MB/s' mean?

comment:2 by z80user, 13 years ago

Windows XP
Download a lot of files with Filezilla client
Server: Windows 2000, Filezilla Server, mode: FTP

Tred = Ethernet 100 mbps +/- = 11.5 MB/s

Server = Dual Pentium3@500MHz 384MB/RAM, low cpu load, only run filezilla server.
Client = Core2Duo 2.16 1GB/RAM, low cpu load when upload, but high when download.

Core2Duo 10/100/1000 - Switch 10/100 - Dual P3 3COM 905C-M-TX 10/100

comment:3 by Tim Kosse, 13 years ago

If you uninstall all virus scanners and firewalls for a test (only safe way to fully disable them), does CPU usage change?

comment:4 by z80user, 13 years ago

i don not use virus scanner, firewalls (it is in another PC), anti-spyware running in memory, only running this programs, in manual sesion.
And not, my conputer don`t have any virus or spyware, or another task to upper the cpu usage when the network is in use. The only limited is the cable is not Category 5e, but used in a transfer between two 10/100/1000 at 35MB/s = 350mbps.

comment:5 by Tim Kosse, 13 years ago

Please try 3.0.10

comment:6 by z80user, 13 years ago

the load of CPU low little.
The code of program low a lot, it is around 10-15% of all CPU load, The other CPU load is the system, the program pherhaps no use the sistem very well. I think it is becouse:

1-. Create and destroy buffer many times, "var = new (4096); delete var;"
2-. Write a lot of time in disk, flush every one packet are fully download.
3-. It use 4 KB for buffers and windows also use 4KB of sector, in this case, run ok, but is 2KB sector or more than 4 KB, can make tree times up to write a part of file: Write 4KB, read 8KB and write the other 4KB if the cluster is 8 KB and buffer 4 KB.

You can be set many buffers: numbers of transfrerences * 2 or more, and use this buffers every time, like a LIFO, and write when the transfers are finish of when the numbres of next buffers = 0 when cange to the next buffers.

comment:7 by Tim Kosse, 13 years ago

The code of program low a lot, it is around 10-15% of all CPU load
The other CPU load is the system

This doesn't appear to be a problem with FileZilla. Looks like your system is just close to hitting some system specific I/O bottleneck. Try a faster HDD and a network card with TCP checksum offloading if you don't have already.

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