The
x11perf
program runs one or more performance tests and reports how fast an X server can
execute the tests.
Many graphics benchmarks assume that the graphics device is used to display the
output of a single fancy graphics application, and that the user gets his work
done on some other device, like a terminal. Such benchmarks usually measure
drawing speed for lines, polygons, text, etc.
Since workstations are not used as standalone graphics engines, but as
super-terminals,
x11perf
measures window management performance as well as
traditional graphics performace.
x11perf
includes benchmarks for the time it
takes to create and map windows (as when you start up an application); to map a
pre-existing set of windows onto the screen (as when you deiconify an
application or pop up a menu); and to rearrange windows (as when you slosh
windows to and fro trying to find the one you want).
x11perf
also measures graphics performance for operations not normally used in
standalone graphics displays, but are nonetheless used frequently by X
applications. Such operations include CopyPlane (used to map bitmaps into
pixels), scrolling (used in text windows), and various stipples and tiles
(used for CAD and color half-toning, respectively).
x11perf
should be used to analyze particular strengths and weaknesses
of servers, and is most useful to a server writer who wants to
analyze and improve a server.
x11perf
is meant to comprehensively exercise just about every X11 operation you can
perform; it does not purport to be a representative sample of the
operations that X11 applications actually use.
While it can be used as a benchmark, it was written and is intended as
a performance testing tool.
As such,
x11perf
DOES NOT whittle down measurements to a single ``HeXStones''
or ``MeXops'' number. We consider such numbers to be uninformative
at best and misleading at worst.
Some servers which are very fast for certain applications can be
very slow for others.
No single number or small set of numbers are sufficient to
characterize how an X implementation will perform on all applications.
However, by knowledge of your favorite application, you
may be able to use the numbers
x11perf
reports to predict its performance on a given X implementation.
That said, you might also want to look at
x11perfcomp(1),
a program to compare the outputs of different
x11perf
runs. You provide a list of files containing results from
x11perf,
and it lays them out in a nice tabular format.
For repeatable results,
x11perf
should be run using a local connection on a
freshly-started server. The default configuration runs each test 5 times, in
order to see if each trial takes approximately the same amount of time.
Strange glitches should be examined; if non-repeatable one might
chalk them up to
daemons and network traffic. Each trial is run for 5 seconds, in order to
reduce random time differences. The number of objects processed per second is
displayed to 3 significant digits, but you'll be lucky on most UNIX system if
the numbers are actually consistent to 2 digits.
x11perf
moves the cursor out of the test window; you should be careful not
to bump the mouse and move it back into the window.
(A prize to people who correctly explain why!!).
Before running a test,
x11perf
determines what the round trip time to the server is, and factors this out of
the final timing reported. It ensures that the server has actually performed
the work requested by fetching a pixel back from the test window, which means
that servers talking to graphics accelerators can't claim that they are done,
while in the meantime the accelerator is painting madly.
By default
x11perf
automatically calibrates the number of repetitions of each test,
so that each should take approximately the same length of time to run across
servers of widely differing speeds. However, since each test must be run to
completion at least once, some slow servers may take a very long time,
particularly on the window moving and resizing tests, and on the arc drawing
tests.
All timing reports are for the smallest object involved. For example, the line
tests use a PolyLine request to paint several lines at once, but report how
many lines per second the server can paint, not how many PolyLine requests per
second. Text tests paint a line of characters, but report on the number of
characters per second. Some window tests map, unmap, or move a single parent
window, but report on how many children windows per second the server can map,
unmap, or move.
The current program is mostly the responsibility of Joel McCormack. It is
based upon the x11perf developed by Phil Karlton, Susan Angebranndt, Chris
Kent, Mary Walker, and Todd Newman, who wanted to assess performance differences between various servers.
Several tests were added in order to write and tune
the PMAX (DECStation 3100) servers.
For a general release to the world,
x11perf
was rewritten to ease making comparisons between widely varying
machines, to cover most important (and unimportant) X functionality,
and to exercise graphics operations in as many different
orientations and alignments as possible.
OPTIONS
x11perf
is solely Xlib based, and
accepts the options listed below:
-display host:dpy
Specifies which display to use.
-sync
Runs the tests in synchronous mode.
Normally only useful for debugging
x11perf .
-pack
Runs rectangle tests so that they pack rectangles right next to each other.
This makes it easy to debug server code for stipples and tiles...if the
pattern looks ugly, you've got alignment problems.
-repeat <n>
Repeats each test
n
times (by default each test is run 5 times).
-time <s>
Specifies how long in seconds each test should be run (default 5 seconds).
-all
Runs all tests. This may take a while.
-range <test1>[,<test2>]
Runs all the tests starting from the specified name test1 until
the name test2, including both the specified tests. The testnames
should be one of the options starting from -dot. (eg) -range line100
will peform the tests from the 100 pixel line test, and go on till the
last test, -range line100,dline10 will do the tests from line100 to
dline10.
-labels
Generates just the descriptive labels for each test specified. See
x11perfcomp
for more details.
-fg color-or-pixel
Specifies the foreground color or pixel value to use.
-bg color-or-pixel
Specifies the background color or pixel value to use.
-clips default
Default number of clip windows.
-ddbg color-or-pixel
Specifies the color or pixel value to use for drawing
the odd segments of a DoubleDashed line or arc.
This will default to the bg color.
-rop <rop0 rop1 ...>
Use specified raster ops (default is GXcopy).
This option only affects graphics
benchmarks in which the graphics function is actually used.
-pm <pm0 pm1 ...>
Use specified planemasks (default is ~0).
This option only affects graphics
benchmarks in which the planemask is actually used.
-depth <depth>
Use a visual with <depth> planes per pixel (default is the default
visual).
-vclass <vclass>
Use a visual with of class <vclass>. <vclass> can be StaticGray, GrayScale,
StaticColor, PseudoColor, TrueColor, or DirectColor. (default is the default
visual).
-reps <n>
Specify the repetion count (Default is number that takes aprox. 5 seconds)
-subs <s0 s1 ...>
Specify the number of sub windows to use in the Window tests.
Default is 4, 16, 25, 50, 75, 100 and 200.
-v1.2
Perform only x11perf Version 1.2 tests using Version 1.2 semantics.
-v1.3
Perform only x11perf Version 1.3 tests using Version 1.3 semantics.
-su
Set the save_under window attribute to True on all windows created by x11perf.
Default is False.
-bs <backing_store_hint>
Set the backing_store window attribute to the given value on all windows
created by x11perf. <backing_store_hint> can be WhenMapped or
Always. Default is NotUseful.