Wow very good to know.

Marco wrote on Yesterday, 18:08:

Thanks for the hint. There are unfortunately no packet drivers available for the 515 😒

Bummer... I've run into very few cards where there isn't a packet driver (or one for a compatible card).

To be completely honest however, although I had dozens of NICs back in the day (and still have a few, even a couple
ISA ones) which I use on the 4-5 DOS systems I still have, I don't tend to try and run DOS on my newer systems, and
haven't needed to go looking for newer packet drivers. In the very rare cases where I've booted DOS on something
newish for testing - I can usually just stuff in a PCI card if I need networking.

I'm sure most newer hardware doesn't have need for packet drivers as DOS has been almost eliminated
from "modern" consideration factors in picking an OS.

So Tests conducted:

SMB Large file Transfer (15MB):
DOS: 428kb/s
WIN311: 788kb/s
WIN95: 750kb/s

FTP Large File Transfer (from Slackware)
WIN31: 837kbps
WIN95: 1120kbps

Not the NUL but fast HDD. Couldnt get wsftp to download to NUL

Further remarks:
- switch port config is in line with NIC config 100MB HD

So at the end I couldn’t get closer to a possible root cause.

I might test another router. But from the current I do easily get 6MB and more for SMB download speed from a modern PC.

My ISA Bus achieves up to 4400kb/s for linear HDD reads so even without busmastering these results are disappointing and more or less identical or slower then the ones of a 3c509.

Next steps:

1. Use another router (for another ftp test)
2. Test the card in my 486dx2 80 as proposed.

Anyway maybe these results do already give someone some more hints?!

Thank you