very slow X sessions on 5.2-RC2

Hi folks

My X sessions are quite slow on my (new) P4, 2.53Ghz machine with
Intel Extreme Graphics (i845GV) "processor" and 256 MB RAM. I can use
one application for sometime, but if I try to switch windows, then I
have to wait like 1 minute for everything to redraw. This keeps on
happening constantly, all the time and it is quite frustrating. My
mouse movements are very jerky and I have to wait quite a while for
any reaction from the system. I used to have an old 800 Mhz P3 with
384 MB ram, running 4.7-STABLE and things were quite fast on that. And
this machine has 3x the clockspeed and a supposedly newer processor.

I am beginning to wonder if this has to do with the on-board graphics
and the amount of memory I have. Intel's website on this chipset says
that this graphics chipset uses shared memory (ie from main memory)
and it can use 64MB if the main memory is more than 128M. In the BIOS
though, I see an option that says allocate 8MB for graphics (This is a
DELL 2400, in case it helps). I am not sure which one is really
correct here and how much memory is being "shared" for the graphics. I
am assuming that 5.2-RC2 (yes, I have to upgrade) is faster than what
I see here. 

The kernel is quite similar to GENERIC, except that practically all
SCSI and wi stuff is out. I am not using ULE or KSE or anything. Just
whatever was default with 5.2-RC2. I am also running KDE 3.2. I know
that my machine itself can do run quite fast, as is evident when I
compile ports. I have never compiled 150 ports in such a short time
before. It only seems like the graphics part is sooo slow. Maybe I
should just get more memory, but I would like to confirm that that is
the case.

In case it helps, these are outputs from 'top' at various times. If
any other information is needed, like dmesg output, I can attach them.
Thanks.

last pid: 57677;  load averages:  0.79,  0.31,  0.12          up 9+22:42:48  00:06:35
79 processes:  2 running, 67 sleeping, 10 zombie
CPU states:  6.2% user,  0.0% nice,  7.4% system, 66.7% interrupt, 19.8% idle
Mem: 137M Active, 38M Inact, 56M Wired, 14M Cache, 35M Buf, 652K Free
Swap: 1024M Total, 181M Used, 843M Free, 17% Inuse

last pid: 57677;  load averages:  1.18,  0.45,  0.18          up 9+22:43:13  00:07:00
79 processes:  2 running, 67 sleeping, 10 zombie
CPU states:  6.2% user,  0.0% nice,  8.1% system, 35.3% interrupt, 50.4% idle
Mem: 137M Active, 37M Inact, 56M Wired, 15M Cache, 35M Buf, 652K Free
Swap: 1024M Total, 181M Used, 843M Free, 17% Inuse

last pid: 80748;  load averages:  0.03,  0.17,  0.13                    up 31+22:19:24  23:43:11
81 processes:  3 running, 66 sleeping, 12 zombie
CPU states: 14.5% user,  0.0% nice,  3.4% system,  0.3% interrupt, 81.8% idle
Mem: 133M Active, 19M Inact, 84M Wired, 8880K Cache, 35M Buf, 656K Free
Swap: 1024M Total, 274M Used, 749M Free, 26% Inuse

last pid: 62836;  load averages:  0.42,  0.32,  0.23                    up 35+22:30:09  23:53:56
101 processes: 5 running, 67 sleeping, 1 stopped, 28 zombie
CPU states: 50.1% user,  0.0% nice,  6.9% system,  0.8% interrupt, 42.2% idle
Mem: 142M Active, 9928K Inact, 84M Wired, 9748K Cache, 35M Buf, 656K Free
Swap: 1024M Total, 328M Used, 696M Free, 32% Inuse

kaarthik