I get similar effects too.
Win2k Pro
ABit KT7A-Raid motherboard (Via chipset, ugh...)
AMD Athlon 1.5ghz
1gig PC133 SDRAM
GeForce3 w/64mb RAM (with latest drivers + DirectX9)
320gig ATA-100 HDDs.
T1 connection. (Rated at 1.3 mbit / 161kb/sec by
http://bandwidthplace.com)
When I'm playing Second Life I'm usually alt+tabbing back and forth between PaintShopPro, Second Life, and the SL forums to find answers to scripting issues I run into.
Usually on any given night I restart SL maybe 2 or 3 times as it starts to get noticeably laggy, and the restart generally helps to spruce things up again.
But as the night goes on and it gets past 10pm PST and I can no longer restart SL, that's when things start to get progressively worse for me. The lag just seems to build up and up to a point where I'm getting sometimes less than 3 FPS.
I'm having a hard time really telling what's going on because the network monitor in SL seems to be doing fine, very rarely goes into the red, and I mean, general activity ingame is still occuring normally, I still see people whizzing by me overhead (if 3 FPS could be called "whizzing" anyway, ha), it's just my client that's flipping out and having difficulties rendering what's going on.
I know my GeForce can handle way more than 3 FPS @ 1024 x 768 heh, in fact at good times I've gotten around 25 FPS in-game. One thing I noticed was that when my lag isn't too bad, the client seems to render a handful of frames nice and smooth, then it'll pause for a half a second, and it'll repeat that almost the whole time. Again, the network monitor is fine during all of this, just seems like maybe my client is getting backed up doing something else.
I did check Task Manager a couple of times and like Xavier, I noticed nview.exe was taking up quite a lot of memory. But even still, it wasn't even close to using up all the RAM I have in my machine.
My virtual memory swap disk is on a different drive to the one I run Second Life from. Both drives have plenty of free space on them.
It almost seems like some kind of memory leak in the SL client ?