tux load/performance questions

Hello,

I have recently started working with TUX and was forced to use it in a
production environment before I had the chance to become completely
familiar with it.  Here is the scenario..

This webserver is dedicated to serving jpg images only.  Approx 500,000
images ranging in size from 1k to 40k

single cpu (Intel(R) Pentium(R) 4 CPU 2.40GHz)
2 GB RAM
3ware hardware IDE RAID 0 80GB
Linux 2.4.21-9.EL (Redhat Enterprise ES)
tux-3.2.14-1

issue:

server can not currently push more than 4 mbps (as measured by iptraf)

I am reluctant to throw hardware at this problem until I can determine
that it is necessary.  I would of not expected to see this sort of load
while pushing only 4 mbps of traffic.  Since this is a production
environment I also am hesitant about 'trying' different software 
versions
on the fly..

thoughts?

diagnostic output taken under peak production load:

more information available upon request of course..

<snip>

 18:23:36  up 1 day,  5:41,  2 users,  load average: 7.96, 5.15, 3.93
 Mem:  2063012k av, 2041188k used,   21824k free

 nobody    15   0   756  756   644 S    18.9  0.0 111:11   0 async IO 0/2
 nobody    16   0   756  756   644 R    14.9  0.0 205:05   0 async IO 0/1
 nobody    15   0   756  756   644 S    10.9  0.0  47:08   0 async IO 0/3
 nobody    15   0   756  756   644 S     6.3  0.0  18:17   0 async IO 0/4
 nobody    15   0   756  756   644 S     0.9  0.0   0:38   0 async IO 0/8
 nobody    15   0   756  756   644 S     0.9  0.0   0:07   0 async IO 0/11
 nobody    15   0   756  756   644 S     0.7  0.0  10:48   0 tux

 Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
sda              77.49        69.59       784.97    7452148   84059990
sda1              0.00         0.00         0.00        122         46
sda2              0.00         0.01         0.02       1440       2128
sda3             77.48        69.57       784.95    7449642   84057816
sdb               0.00         0.01         0.00        568          0
sdb1              0.00         0.00         0.00         88          0

procs                      memory      swap          io     system
cpu
 r  b   swpd   free   buff  cache   si   so    bi    bo   in    cs us sy id wa
 1  0      4  15252 138180 1695272    0    0    35   393  238   365  0 26 63 10


Device:    rrqm/s wrqm/s   r/s   w/s  rsec/s  wsec/s    rkB/s    wkB/s
avgrq-sz avgqu-sz   await  svctm  %util
sda          0.01  29.33  8.69 68.81   69.58  785.17    34.79   392.58
11.03     0.33    4.21   1.68  13.02

</snip>