last results with SSE2

5 minutes.
107 games played.
this is result:
-----------------FireBird_11_w32_ms [nmr off]-----------------
FireBird_11_w32_ms [nmr off] - IvanHoe-Beta-999963-Beta-my build : 15.5/29 7-5-17 (0===0===11===0001==1===1=11== ) 53% +21
FireBird_11_w32_ms [nmr off] - Rybka 3 w32 : 29.5/50 17-8-25 (1=1111=0====1==11=1=0=1===10111==0=0=1=00=0==1=1==) 59% +63
-----------------IvanHoe-Beta-999963-Beta-my build-----------------
IvanHoe-Beta-999963-Beta-my build - FireBird_11_w32_ms [nmr off] : 13.5/29 5-7-17 (1===1===00===1110==0===0=00== ) 47% -21
IvanHoe-Beta-999963-Beta-my build - Rybka 3 w32 : 15.5/28 10-7-11 (001100=1=10=1=1=010=1====1=1? ) 55% +35
-----------------Rybka 3 w32-----------------
Rybka 3 w32 - FireBird_11_w32_ms [nmr off] : 20.5/50 8-17-25 (0=0000=1====0==00=0=1=0===01000==1=1=0=11=1==0=0==) 41% -63
Rybka 3 w32 - IvanHoe-Beta-999963-Beta-my build : 12.5/28 7-10-11 (110011=0=01=0=0=101=0====0=0? ) 45% -35

this is my optimized compile(not piece values and without SSE2) with msvc 2008.
and again:
no book.
arena gui.
64 mb pawn hash.
128 mb common hash.

and i recompile ivanhoe again with SSE2. this is result:
-----------------FireBird_11_w32_ms [nmr off]-----------------
FireBird_11_w32_ms [nmr off] - IvanHoe-Beta-999963-Beta-my build-SSE 2       : 17.0/35 6-7-22 (====1===1====10000=====0===1=010=1=?              )  49%    -7
-----------------IvanHoe-Beta-999963-Beta-my build-SSE 2-----------------
IvanHoe-Beta-999963-Beta-my build-SSE 2 - FireBird_11_w32_ms [nmr off]       : 18.0/35 7-6-22 (====0===0====01111=====1===0=101=0=?              )  51%    +7
 they almost have same strength.

new version of engines

90 games played.
5 minutes games.

   Engine                       Score               Fi              Fi              Iv              Ry    S-B
1: FireBird_11_w32_ms [nmr off] 28.0/45 ··············· 11==00=1011===1 ====1======1101 1=1111=0====1==  574.00
2: FireBird_11_w32_ms [nmr on]  23.5/45 00==11=0100===0 ··············· =00============ =11=11=11===1==  490.25
3: IvanHoe-Beta-999964-Beta     22.5/45 ====0======0010 =11============ ··············· 1001=1011====0=  495.75
4: Rybka 3 w32                  16.0/45 0=0000=1====0== =00=00=00===0== 0110=0100====1= ···············  391.50

-----------------FireBird_11_w32_ms [nmr off]-----------------
FireBird_11_w32_ms [nmr off] - FireBird_11_w32_ms [nmr on]             : 9.0/15 6-3-6 (11==00=1011===1)  60%   +70
FireBird_11_w32_ms [nmr off] - IvanHoe-Beta-999964-Beta                : 9.0/15 4-1-10 (====1======1101)  60%   +70
FireBird_11_w32_ms [nmr off] - Rybka 3 w32                             : 10.0/15 6-1-8 (1=1111=0====1==)  67%  +123
-----------------FireBird_11_w32_ms [nmr on]-----------------
FireBird_11_w32_ms [nmr on] - FireBird_11_w32_ms [nmr off]             : 6.0/15 3-6-6 (00==11=0100===0)  40%   -70
FireBird_11_w32_ms [nmr on] - IvanHoe-Beta-999964-Beta                 : 6.5/15 0-2-13 (=00============)  43%   -49
FireBird_11_w32_ms [nmr on] - Rybka 3 w32                              : 11.0/15 7-0-8 (=11=11=11===1==)  73%  +173
-----------------IvanHoe-Beta-999964-Beta-----------------
IvanHoe-Beta-999964-Beta - FireBird_11_w32_ms [nmr off]                : 6.0/15 1-4-10 (====0======0010)  40%   -70
IvanHoe-Beta-999964-Beta - FireBird_11_w32_ms [nmr on]                 : 8.5/15 2-0-13 (=11============)  57%   +49
IvanHoe-Beta-999964-Beta - Rybka 3 w32                                 : 8.0/15 5-4-6 (1001=1011====0=)  53%   +21
-----------------Rybka 3 w32-----------------
Rybka 3 w32 - FireBird_11_w32_ms [nmr off]                             : 5.0/15 1-6-8 (0=0000=1====0==)  33%  -123
Rybka 3 w32 - FireBird_11_w32_ms [nmr on]                              : 4.0/15 0-7-8 (=00=00=00===0==)  27%  -173
Rybka 3 w32 - IvanHoe-Beta-999964-Beta                                 : 7.0/15 4-5-6 (0110=0100====1=)  47%   -21

nmr: NMR smooth scaling option
pawn hash size was 64 mb.
common hash size was 128 mb.
firebird 1.1 with nmr off(new default) had best results.
IvanHoe-Beta-999964-Beta had good results. tuning that may pruduce better engine.
Each engine had 2 cores.
GUI was Arena.
Considerable advantage of IvanHoe is that it is open source but firebird isn't open source.

Best versions

109 games played. each side has 5 minutes.
cpu: dual core.
pawn hash size: 128 mb again.
  Engine                               Score    
1: FireBird_101_w32 [nmv enabled]       20.5/36
2: Rybka 3 w32                          20.5/37
3: FireBird_101_w32 [nmv disabled]      18.5/36
4: Igorrit_0086v9_w32                   18.0/37
5: IvanHoe-Beta-999965-Beta [optimised] 17.5/36
6: IvanHoe-Beta-999965-Beta             14.0/36

-----------------FireBird_101_w32 [nmv disabled]-----------------
FireBird_101_w32 [nmv disabled] - FireBird_101_w32 [nmv enabled]       : 2.5/8 0-3-5  31%  -139
FireBird_101_w32 [nmv disabled] - Igorrit_0086v9_w32                   : 3.5/7 1-1-5  50%    ±0
FireBird_101_w32 [nmv disabled] - IvanHoe-Beta-999965-Beta             : 4.5/7 3-1-3  64%  +100
FireBird_101_w32 [nmv disabled] - IvanHoe-Beta-999965-Beta [optimised] : 4.5/7 2-0-5  64%  +100
FireBird_101_w32 [nmv disabled] - Rybka 3 w32                          : 3.5/7 2-2-3  50%    ±0
-----------------FireBird_101_w32 [nmv enabled]-----------------
FireBird_101_w32 [nmv enabled] - FireBird_101_w32 [nmv disabled]       : 5.5/8 3-0-5  69%  +139
FireBird_101_w32 [nmv enabled] - Igorrit_0086v9_w32                    : 4.0/7 2-1-4  57%   +49
FireBird_101_w32 [nmv enabled] - IvanHoe-Beta-999965-Beta              : 3.0/7 0-1-6  43%   -49
FireBird_101_w32 [nmv enabled] - IvanHoe-Beta-999965-Beta [optimised]  : 4.0/7 2-1-4  57%   +49
FireBird_101_w32 [nmv enabled] - Rybka 3 w32                           : 4.0/7 3-2-2  57%   +49
-----------------Igorrit_0086v9_w32-----------------
Igorrit_0086v9_w32 - FireBird_101_w32 [nmv disabled]                   : 3.5/7 1-1-5  50%    ±0
Igorrit_0086v9_w32 - FireBird_101_w32 [nmv enabled]                    : 3.0/7 1-2-4  43%   -49
Igorrit_0086v9_w32 - IvanHoe-Beta-999965-Beta                          : 5.0/7 4-1-2  71%  +156
Igorrit_0086v9_w32 - IvanHoe-Beta-999965-Beta [optimised]              : 3.0/8 0-2-6  38%   -85
Igorrit_0086v9_w32 - Rybka 3 w32                                       : 3.5/8 0-1-7  44%   -42
-----------------IvanHoe-Beta-999965-Beta-----------------
IvanHoe-Beta-999965-Beta - FireBird_101_w32 [nmv disabled]             : 2.5/7 1-3-3  36%  -100
IvanHoe-Beta-999965-Beta - FireBird_101_w32 [nmv enabled]              : 4.0/7 1-0-6  57%   +49
IvanHoe-Beta-999965-Beta - Igorrit_0086v9_w32                          : 2.0/7 1-4-2  29%  -156
IvanHoe-Beta-999965-Beta - IvanHoe-Beta-999965-Beta [optimised]        : 2.5/7 1-3-3  36%  -100
IvanHoe-Beta-999965-Beta - Rybka 3 w32                                 : 3.0/8 0-2-6  38%   -85
-----------------IvanHoe-Beta-999965-Beta [optimised]-----------------
IvanHoe-Beta-999965-Beta [optimised] - FireBird_101_w32 [nmv disabled] : 2.5/7 0-2-5  36%  -100
IvanHoe-Beta-999965-Beta [optimised] - FireBird_101_w32 [nmv enabled]  : 3.0/7 1-2-4  43%   -49
IvanHoe-Beta-999965-Beta [optimised] - Igorrit_0086v9_w32              : 5.0/8 2-0-6  63%   +92
IvanHoe-Beta-999965-Beta [optimised] - IvanHoe-Beta-999965-Beta        : 4.5/7 3-1-3  64%  +100
IvanHoe-Beta-999965-Beta [optimised] - Rybka 3 w32                     : 2.5/7 2-4-1  36%  -100
-----------------Rybka 3 w32-----------------
Rybka 3 w32 - FireBird_101_w32 [nmv disabled]                          : 3.5/7 2-2-3  50%    ±0
Rybka 3 w32 - FireBird_101_w32 [nmv enabled]                           : 3.0/7 2-3-2  43%   -49
Rybka 3 w32 - Igorrit_0086v9_w32                                       : 4.5/8 1-0-7  56%   +42
Rybka 3 w32 - IvanHoe-Beta-999965-Beta                                 : 5.0/8 2-0-6  63%   +92
Rybka 3 w32 - IvanHoe-Beta-999965-Beta [optimised]                     : 4.5/7 4-2-1  64%  +100
nmv: null move verification
in InanHoe-optimised i used firebird's values.
it seems that  FireBird 1.01 is best of ippolit derivative engines.
my msvc compile: http://rapidshare.com/files/350961483/IvanHoe-Beta-999965-Beta.7z.html
good luck

1 hour tournaments

1 hour each side:
-----------------FireBird_101_w32-----------------
FireBird_101_w32 - Rybka 3 w32 : 4.0/8 1-1-6 (======01)  50%    ±0
-----------------Rybka 3 w32-----------------
Rybka 3 w32 - FireBird_101_w32 : 4.0/8 1-1-6 (======10)  50%    ±0

but for more accurate results, we will need more games.
null move verification had enabled.
128 mb pawn hash.
256 mb common hash table
128 mb common endgame tablebases
GUI: arena

Firebird 1.01

With default settings:
Null move verification = enabled
-----------------FireBird_101_w32-----------------
FireBird_101_w32 - Rybka 3 w32 : 3.5/8 0-1-7 (====0===)  44%   -42
-----------------Rybka 3 w32-----------------
Rybka 3 w32 - FireBird_101_w32 : 4.5/8 1-0-7 (====1===)  56%   +42

Null move verification = disabled
-----------------FireBird_101_w32-----------------
FireBird_101_w32 - Rybka 3 w32 : 7.0/11 4-1-6 (0=11==11===?)  64%  +100
-----------------Rybka 3 w32-----------------
Rybka 3 w32 - FireBird_101_w32 : 4.0/11 1-4-6 (1=00==00===?)  36%  -100

Null move verification decreases its strength. without that, it is very strong!

New firebird 1.0

Results of 5' games:
-----------------FireBird_10_w32-----------------
FireBird_10_w32 - Rybka 3 w32             : 28.0/42 17-3-22 (1==0=111===1==01=0==1==1==11=1=11==111=1==?)  67%  +123
-----------------Rybka 3 w32-----------------
Rybka 3 w32 - FireBird_10_w32             : 14.0/42 3-17-22 (0==1=000===0==10=1==0==0==00=0=00==000=0==?)  33%  -123
No book
GUI: arena
No persistent hash for rybka 3
Two engines has used 2 cores.
256 MB Hash

Rybka vs best of other engines !

Last results of 5 minutes games:
   Engine                   Score 
1: Igorrit_0086v9_w32       14.5/25
2: Rybka 3 w32              14.0/25
3: IvanHoe-Beta-999968-Beta 13.0/24
4: RobboLito_009_w32        10.0/24
5: FireBird 1.0 beta w32    9.5/24

-----------------FireBird 1.0 beta w32-----------------
FireBird 1.0 beta w32 - Igorrit_0086v9_w32       : 2.0/6  33%  -123
FireBird 1.0 beta w32 - IvanHoe-Beta-999968-Beta : 1.5/6  25%  -191
FireBird 1.0 beta w32 - RobboLito_009_w32        : 3.5/6  58%   +56
FireBird 1.0 beta w32 - Rybka 3 w32              : 2.5/6  42%   -56
-----------------Igorrit_0086v9_w32-----------------
Igorrit_0086v9_w32 - FireBird 1.0 beta w32       : 4.0/6  67%  +123
Igorrit_0086v9_w32 - IvanHoe-Beta-999968-Beta    : 3.5/6  58%   +56
Igorrit_0086v9_w32 - RobboLito_009_w32           : 4.0/6  67%  +123
Igorrit_0086v9_w32 - Rybka 3 w32                 : 3.0/7  43%   -49
-----------------IvanHoe-Beta-999968-Beta-----------------
IvanHoe-Beta-999968-Beta - FireBird 1.0 beta w32 : 4.5/6  75%  +191
IvanHoe-Beta-999968-Beta - Igorrit_0086v9_w32    : 2.5/6  42%   -56
IvanHoe-Beta-999968-Beta - RobboLito_009_w32     : 3.0/6  50%    ±0
IvanHoe-Beta-999968-Beta - Rybka 3 w32           : 3.0/6  50%    ±0
-----------------RobboLito_009_w32-----------------
RobboLito_009_w32 - FireBird 1.0 beta w32        : 2.5/6  42%   -56
RobboLito_009_w32 - Igorrit_0086v9_w32           : 2.0/6  33%  -123
RobboLito_009_w32 - IvanHoe-Beta-999968-Beta     : 3.0/6  50%    ±0
RobboLito_009_w32 - Rybka 3 w32                  : 2.5/6  42%   -56
-----------------Rybka 3 w32-----------------
Rybka 3 w32 - FireBird 1.0 beta w32              : 3.5/6  58%   +56
Rybka 3 w32 - Igorrit_0086v9_w32                 : 4.0/7  57%   +49
Rybka 3 w32 - IvanHoe-Beta-999968-Beta           : 3.0/6  50%    ±0
Rybka 3 w32 - RobboLito_009_w32                  : 3.5/6  58%   +56

61 games shows that rybka 3(with 1 gb persistent hash) is stronger than all other engines or at least equal.
firebird 1.0 beta is weaker than other MP engines.
Note: In these games rybka used 1 gb persistent hash.
contempt play = 0.
other engines had 128 mb pawn hash.
hash table size for all engines was 256.
GUI is arena 2.0.1
Longer games maybe better for analysis.
Fischer random chess(chess 960) gives better view(for effect of persistent hash).
good luck.