Thank you for sharing this program. It works on Windows NT 4.0 and a 486. The results obtained with this program are similar to what I concluded from my stop watch tests. I have a 3Com 3c90C-TX-M, 10/100Base-TX.

From 486-to-P3
Writing: 21.8 mbps, or 2.73 MB/s [CPU bounced between 50-100%]
Reading: 32.3 mbps, or 4.04 MB/s [CPU solid at 100%]

For comparison, I tested my dual PIII-850 to a 1.6 MHz laptop and get:
Writing: 63.4 mbps, or 7.93 MB/s
Reading: 65.1 mbps, or 8.14 MB/s

Not sure why I didn't get closer to 85 mbps on the faster computers. The CPU was only at 30%. Perhaps related to the DD-WRT I put on my router, or someone leaving Youtube open somewhere, dunno...

I'm pretty pleased with the 486 reading speed though, it is only half the speed of a P3. I'm not sure why the CPU utilisation bounced between 50-100% on the writing, but it is probably some how related to the slower writing speed.

The other open questions is if an Intel NIC will perform any better on a 486.

EDIT: I noticed that Rx and Tx checksum offload are disabled by default on my NIC, however enabling them did not increase throughput at all.

I discovered something about XP file sharing. It is apparently not capable of saturating a Gigabit link. Two different high end machines I have both get a Max of around 45 megabytes/sec. This is with 3 different NICs, including two PCIe ones. I also tried some tweaks like tcp window size and window scaling (TCP Optimizer) with no improvement. I tried a RAMdisk just in case it was a storage subsystem bottleneck. And I pulled files from a Win7 and a Linux source, both capable of saturating this link.

Windows 7 on the test machine doubles the throughput to around 90 megabytes /sec with a PCIe NIC. Apparently Vista is good too.

Those are interesting finds. I suppose the next logical step would be to determine if there is some sort of update/fix for gigabit networks on XP.

I have been reading about XP and gigabit speeds but I have not come across any specific fixes. There is an interesting article about XP Firewall having a problem with large send offload but I'm not sending data so disabling that service is probably no solution..

We have the benefit of hindsight. Back in the midst of the 90's, I'd say you can't go wrong with 3COM. Intel was always a close second.

Now I would say pick Intel every time. I think the marketing machine of 3COM pushed Intel out of the top slot, but my own informal testing shows that those old 82557 Intel NICs were better.

feipoa wrote:

The other open questions is if an Intel NIC will perform any better on a 486.

The performance of an Intel Pro 100S was the same as the 3Com 3c905C-TX-M on a 486 (Cyrix 5x86-133/4x).

I like 3C509's for an ISA card because there's squillions of them around, and you can use them on 8088/8086's.