I just flashed KONGmod on my e3000 to use with a DLNA TV (Sony) and a USB HD. I am very happy about the functionality but I am not experiencing the performance I expected for NAS.

I get slow read and write, using both SAMBA and ProFTP. The slowness is not caused by the file-system, USB drive or connetion, but by the CPU consumed by the SAMBA and ProFTP deamons respectively.

Is this a known problem? From the forums it looks like people are expecting that kind of transfer rate (I can't imagine why though, is the I/O system really limited to that performance?) 

(NOOB question :) Where can I find instructions on downloads for build-environment, source and compilation? I have looked around the myopenrouter page and was not able to figure it out (atleast straight away :)

-- Tests

I have connected my Win7 computer with a CAT6 cable to port-1 (external marking) of the e3000, so WiFI is not a problem.

Using dd (see below) I have timed transfer rates from and to the USB-drive:

Direct READ speed: 22.28M/s
Direct WRITE speed: 16.8M/s  

Using the Win7 explorer FTP and SMB functionality I have measured the "user percieved speed":

FTP READ & WRITE: changing from 400 K/s to 7 M/s

SMB READ & WRITE: Relatively stable between 6 M/s and 7 M/s

Using "top", I have confirmed that the problem is that both ProFTP and SAMBA are maxing out the CPU on the e3000.

-- DETAILS

Version: DD-WRT v24-sp2 (01/03/12) stdkong (SVN revision 18050M)

Directly READING a 1.2G real-wold test-file: 22.28 M/s

root@fisk-rt:/mnt/Video# time dd if=test.file of=/dev/null bs=1M

1183+1 records in
1183+1 records out
real    0m 53.09s
user    0m 0.00s
sys     0m 17.10s
# ls -l test.file
-rw-r--r--    1 root     root     1240572305 Jan  5 00:48 test.file

Directly WRITING a 200M file of zeros: 16.80 M/s

root@fisk-rt:/mnt/Video# time dd if=/dev/zero of=test.file2 bs=1M count=200
200+0 records in
200+0 records out
real    0m 11.90s
user    0m 0.00s
sys     0m 6.74s

MOUNT details:

root@fisk-rt:/mnt/Video# mount
[... removed lines of no interest to this ...]
/dev/scsi/host1/bus0/target0/lun0/part1 on /opt type ext3 (rw,data=ordered)
/dev/scsi/host1/bus0/target0/lun0/part3 on /mnt type ext3 (rw,data=ordered)

ProFTP top "screenshot":

Mem: 54388K used, 4452K free, 0K shrd, 292K buff, 40320K cached
CPU:  2.1% usr 34.1% sys  0.0% nic  0.0% idle  0.1% io  1.9% irq 61.4% sirq
Load average: 1.97 1.07 0.50 2/45 5314
  PID  PPID USER     STAT   VSZ %VSZ %CPU COMMAND
 5119  2774 root     R     1800  3.0 95.8 proftpd: hej - 192.168.33.100: RETR [...]

Samba top "screenshot":

Mem: 53644K used, 5196K free, 0K shrd, 428K buff, 39096K cached
CPU: 12.1% usr 47.6% sys  0.0% nic  0.0% idle  0.0% io  1.5% irq 38.6% sirq
Load average: 1.66 0.92 0.59 2/44 5773
  PID  PPID USER     STAT   VSZ %VSZ %CPU COMMAND
 2838  2806 root     R     5272  8.9 85.5 /usr/sbin/smbd -D --configfile=/tmp/sm