View Full Version : DOS FTP Speed - woot!

December 28th, 2009, 11:53 AM
I know this code is good on old machines, and I probably could squeeze a little more out. But just for grins, I tried it on what I would call a 'high spec' machine:

Pentium 133
100 Mb/sec LAN adapter
IDE hard drive

FTP was disappointing - about two megabytes per second to send or receive. That works out to around 16Mb/sec (bits), which is more than a normal 10Mb/sec LAN can do, so that part was fine. But it seemed like it should be faster.

Then I did a face palm .. I was including disk I/O. Two megabytes per second on a machine that old makes sense.

I just ran a "speed test" now - it sends 4MB of junk in memory to a Linux box, which throws it away without even trying to write it. A receive test is done the same way.

To send took 0.77 seconds. That works out to 5.19MB/sec, or 41.55Mb/sec. To receive took 0.66 seconds. That works out to 6.06MB/sec, or 48.48Mb/sec. In simple English, I'm getting nearly 40 to 50% of the wire speed that my home LAN can provide using the same code that I use on a 4.77Mhz PCjr! With the small buffers sizes too! And compiled for an 8088 CPU!

I'm using the standard DOS/BIOS timer tick, so there is 55ms of slop in the timings. But you get the idea.