10mb / 100 mb in Mediator

[kas1e]

hi all. anybody to know any difference between 10mb and 100mb card _in mediator_ ? i am talk about speed. becouse i just test today 2 card 10mb realtek, and 100mb realtek, and found that botch card work on the same speed. Maybe 100mb little _slower_. Of course i do not expect big difference, but some difference i think must be, no ?

[Karlos]

Given the general state of existing tcp stacks for 68K amigas I'm not particularly surprised*.

There's also the issue (for 100M cards) of the CPU <-> Mediator bus speeds, which are not terribly high.

-edit-

*I seem to recall this is one of Patrik's area of interest, perhaps he can throw some extra light on the issue.

[MskoDestny]

What kind of mediator is this attached to and what else do you have in the mediator?  The Zorro 2 bus is rather slow. 3.4MB/s theoretical maximum and the theoretical maximum for 10baseT is 1.25MB/s.  If you have a graphics card, the Zorro 2 bus could easily be saturated leaving none less for the extra bandwidth of the 100BaseT card.

[kas1e]

i have mediator1200 with 4 pci slots. Video board Voodoo Banshe 16mb, and 2 realtecks (10 and 100mb). And bppc with 060-66mhz / 603e-260mhz. After i resoldering 060 over old 040 network transerfs speedup in 3 times, but what i do not have any difference betwin 10mb and 100mb cards .. (why elbox did drivers for 100mb cards anyway, if it is the same
as 10mb cards)

ps. i tryed to download 6.4mb file from network, by smb-handler, and time: 8seconds. So, 10mbit = 1.2mb => 6.4mb/8s=0.8 So, 0.8 < 1.2 => 10mb do not work on full power ?

[Karlos]

The gain using 060 over 040 should set give hints as to where the real bottlenecks are. If the whole system was working ideally (true DMA, busmastering and what not), the CPU would be about the last thing to have any effect on transfer speeds here.

However, you ultimately end up copying data to/from the network card, over the bus to system memory using the CPU. To make it worse, the typical stack implementation tends to cause  data to be re-copied as it passes between layers.

Hence the speed of these things is strongly dependent on the CPU. Even if you had a super fast CPU, you won't be able to reach the full potential of the 100M card on this hardware before you hit bus saturation on the mediator.

[kas1e]

interesting to test oos4 for 603 maybe tranfers will really speedup

[adolescent]

kas1e wrote:

ps. i tryed to download 6.4mb file from network, by smb-handler, and time: 8seconds. So, 10mbit = 1.2mb => 6.4mb/8s=0.8 So, 0.8 < 1.2 => 10mb do not work on full power ?

SMB has a lot of overhead, so these numbers might not be that bad.  Try an FTP transfer to get a more accurate benchmark.