[nylug-talk] LOWMEM vs. HIGHMEM performance advantage?

[jh]

I have an application that appears to slow down once it starts using 
about 900 megs of memory.

Interestingly, from dmesg:

[42949372.960000] 1150MB HIGHMEM available.
[42949372.960000] 896MB LOWMEM available.

Is HIGHMEM slower, or are there circumstances or kernel configs such 
that I could be seeing such a slowdown once memory usage goes above a 
certain level?

Thanks.

jh