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-   -   poor 2d performance (http://www.nvnews.net/vbulletin/showthread.php?t=10971)

Ender 04-29-03 07:48 AM

poor 2d performance
 
What is the deal with the current very poor 2d performance. The VESA driver and the NV driver included in X4.3 are both faster. That's just not right! :(

kow 04-29-03 10:16 AM

My open 2d openGl programs seem to be running at least as fast as previous Nvidia driver releases and definately much faster than nv driver. You sure the driver's your problem?

Ender 04-29-03 10:20 AM

i'm not talking about OpenGL performance
 
I'm just talking about the normal 2d X11 video driver, not about the OpenGL performance.

xobnis 04-29-03 10:59 AM

Re: i'm not talking about OpenGL performance
 
Quote:

Originally posted by Ender
I'm just talking about the normal 2d X11 video driver, not about the OpenGL performance.
I am having 2D performance problems also. I am not sure if this is related but when I run the stock X4.3 drivers my X process is using about 91MB of mem but when I use the nvidia drivers (newly release or previous versions) my X process is using about 271MB of mem.

OS: RH 9.0
Dell Inspiron 8200 512MB DDR with gforce4 440 Go 64MB

bwkaz 04-29-03 12:06 PM

Re: Re: i'm not talking about OpenGL performance
 
Quote:

Originally posted by xobnis
when I run the stock X4.3 drivers my X process is using about 91MB of mem but when I use the nvidia drivers (newly release or previous versions) my X process is using about 271MB of mem.
Nope, it's not.

From the 4363 README:

Quote:

Q: Why does X use so much memory?

A: When measuring any application's memory usage, you must be
careful to distinguish between physical system RAM used and virtual
mappings of shared resources. For example, most shared libraries exist
only once in physical memory but are mapped into multiple processes.
This memory should only be counted once when computing total memory
usage. In the same way, the video memory on a graphics card or
register memory on any device can be mapped into multiple processes.
These mappings do not consume normal system RAM.

This has been a frequently discussed topic on XFree86 mailing
lists; see, for example:

http://marc.theaimsgroup.com/?l=xfre...5767116567&w=2

The `pmap` utility described in the above thread and available here:

http://web.hexapodia.org/~adi/pmap.c

is a useful tool in distinguishing between types of memory mappings.
For example, while `top` may indicate that X is using several hundred
MB of memory, the last line of output from pmap:

mapped: 287020 KB writable/private: 9932 KB shared: 264656 KB

reveals that X is really only using roughly 10MB of system RAM
(the "writable/private" value).

Note, also, that X must allocate resources on behalf of X clients (the
window manager, your web browser, etc); X's memory usage will increase
as more clients request resources such as pixmaps, and decrease as
you close X applications.
To use pmap, put it in a directory by itself and just run make pmap (note: in this case, you don't need a Makefile). Then, ./pmap `pidof X`, like the thread says.

On my machine, the reason that ps and top both report X using ungodly amounts of memory is that the X driver mmap's /dev/nvidia0, twice. Each mmap appears to "consume" (even though it doesn't) 128MB of memory, which is the amount of my video RAM.

So none of this 256MB of space is being put in system memory -- it's my video RAM instead. I bet if you look through the pmap output on your machine, you'll see something very similar.


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