XO battery/performance

[Yioryos Asprobounitis]

> If you want an idea of low-level performance, I can suggest
> running LMBench.
> 

Got the Debian lmbench_3.0-a7 source that compiles and runs fine w/o bitkeeper.
Run the hardware part of the tests on the XO-1.5 (os880) and xo-1.75 (os12- correct kernel) with the same configuration.

What was striking was that the XO-1.75 used 25% of the battery for 1 run while the XO-1.5 used 65% of the battery!

Most of the test had empty values but the informative ones (below) show that the XO-1.5 is better in basic integer operations and memory bandwidth while the XO-1.75 is better in float and double operations as well as in memory latency.
I'm not sure how much this means for real life usage :-/
But since I did it, here are the results and a comparison based on the best of 3 values for each machine (hopefully the text alignment will be preserved).

                 L M B E N C H  3 . 0   S U M M A R Y
                 ------------------------------------
		 (Alpha software, do not distribute)

Basic system parameters
------------------------------------------------------------------------------
Host                 OS Description              Mhz  tlb  cache  mem   scal
                                                     pages line   par   load
                                                           bytes  
--------- ------------- ----------------------- ---- ----- ----- ------ ----
xo-1.5    Linux 2.6.35.       i686-pc-linux-gnu 1000    64    64 2.3900    1
xo-1.75   Linux 3.0.19_        armv7l-linux-gnu  796     8    32 1.0000    1


Basic integer operations - times in nanoseconds - smaller is better
-------------------------------------------------------------------
Host                 OS  intgr intgr  intgr  intgr  intgr  
                          bit   add    mul    div    mod   
--------- ------------- ------ ------ ------ ------ ------ 
xo-1.5    Linux 2.6.35. 1.0100 0.0400 1.3500   96.5   55.2
xo-1.75   Linux 3.0.19_ 1.2600 0.1400 3.8800  153.5   33.8
1.5 > 1.75              1.2475	 3.5  2.874   1.590   0.612


Basic float operations - times in nanoseconds - smaller is better
-----------------------------------------------------------------
Host                 OS  float  float  float  float
                         add    mul    div    bogo
--------- ------------- ------ ------ ------ ------ 
xo-1.5    Linux 2.6.35. 7.0300 7.5400   73.3   92.5
xo-1.75   Linux 3.0.19_ 6.2800 7.5400   26.4   50.5
1.75 > 1.5              1.119  1.000	2.777  1.832


Basic double operations - times in nanoseconds - smaller is better
------------------------------------------------------------------
Host                 OS  double double double double
                         add    mul    div    bogo
--------- ------------- ------  ------ ------ ------ 
xo-1.5    Linux 2.6.35. 7.0300 8.0400   73.5   92.5
xo-1.75   Linux 3.0.19_ 6.2800 7.5400   44.0   76.9
1.75 > 1.5              1.119  1.066	1.670  1.203


*Local* Communication bandwidths in MB/s - bigger is better
-----------------------------------------------------------------------------
Host                OS  Pipe AF    TCP  File   Mmap  Bcopy  Bcopy  Mem   Mem
                             UNIX      reread reread (libc) (hand) read write
--------- ------------- ---- ---- ---- ------ ------ ------ ------ ---- -----
xo-1.5    Linux 2.6.35.                               306.1  307.0 458. 646.6
xo-1.75   Linux 3.0.19_                               151.0  143.6 216. 328.1
1.5 > 1.75					      2.02   2.13  2.12 1.97 


Memory latencies in nanoseconds - smaller is better
    (WARNING - may not be correct, check graphs)
------------------------------------------------------------------------------
Host                 OS   Mhz   L1 $   L2 $    Main mem    Rand mem    Guesses
--------- -------------   ---   ----   ----    --------    --------    -------
xo-1.5    Linux 2.6.35.  1000 6.0720   29.1  100.7       361.7
xo-1.75   Linux 3.0.19_   796 3.8060   19.3   99.8       257.7
1.75 > 1.5		      1.595    1.508 1.009       1.404