jfjr@mbunix.mitre.org (Freedman) (01/30/91)
To all who have replied, thanks and my apologies for not being clear.
I aware that I have extended memory and I have books/manuals on both.
Here is my question rephrased and detailed.
I have a Compaq 386/20e running DOS 3.3 with 4 megs of memory.
I have the Clarkson packet drivers installed and I am building
a TCP/IP analysis tool. One of the things I would like to do
is to sit on the net and just receive and record all packets
(time stamp them) for a while. I can receive and I have
a millisecond timer (thanks for the help folks). The packets
can come at me fast - up to 1.5k a packet with 2-3 millisecond
separation-. My receiver runs at interrupt level as does my timer.
Both EMS and XMS involve some fiddling around at interrupt level.
I am concerned about stepping on my own feet with either approach.
I am not concerned with portability or price. Just performance.
full protected mode might be nice but I have to support the
packet drivers too. I can get more memory or fancier hardware
if I really need it(I think;) ).
So what is the best choice EMS with its timeconsuming paging,
XMS with switching back and forth from protected mode?.
Anybody got advice.
Jerry Freedman,Jr
dlow@pollux.svale.hp.com (Danny Low) (01/31/91)
> So what is the best choice EMS with its timeconsuming paging, >XMS with switching back and forth from protected mode?. >Anybody got advice. > Jerry Freedman,Jr Since you have a 386, XMS SHOULD be faster BUT "One test is worth a thousand opinions." Write some test programs and measure the performance. If you use a large enough sample run, the system clock should have enough resolution to give accurate results and the timing overhead should be minimal. Danny Low "Question Authority and the Authorities will question You" Valley of Hearts Delight, Silicon Valley HP CPCD dlow@pollux.svale.hp.com