[Death Adder]

Here is a new version of the speed testing program. This one allows the pipeline to fill up and as such will give different results than before. This test seems to run a lot better for me which suggests the the P4 pipeline is quite nasty for floating point.

Here are my numbers for the new program (1.8Ghz P4)
Integer: 1.462
Single: 1.311
Double: 1.292

As you can see, the numbers are a lot closer now. This makes floating point worth it.

PS: The attached program was compiled unoptimized and compiled for a 386 so anyone should be able to run it. If compiled optimized the three numbers are basically equal.

[ger21]

P3 750

2.453
2.390
2.438

[Death Adder]

That's better. Now both you and I are seeing around the same speed for all three tests. This goes to prove that pipelining and memory access can make a big difference in the results. This also makes me comfortable that floating point should be OK to use in the cutting simulator.

Thanks!

P3 750

2.453
2.390
2.438

[MrBean]

AMD 64bit 3400+

int 0.703
float 0.578
double 0.594

regards Terry.....

[Death Adder]

Thanks MrBean! That's what I like to see: The floating point version was actually faster than the integer version! That's esp good because the floating point unit has a seperate pipeline from the main processor. That means that while the FPU is crunching on numbers the integer portion can do other things (branching, loops, sending data to the video card, etc).

This settles it. I hope to start coding up a test application w/ the floating point array idea sometime tomorrow. Hopefully I'll have something else people can run in a few days.

[DAB_Design]

P4 2.2

1.0000
.875
.875

[JFettig]

I dont know what this is but...
Dothan 1.7ghz
Time for int test: 1.041000
Time for float test: 0.841000
Time for double test: 0.821000

Jon

[fyffe555]

0.56
0.51
0.51

amd64 @ 2.8ghz

results are inconsistent but float and double are usually the same?

Andrew

[Death Adder]

Thanks again all! This is providing some interesting data.

The results will be inconsistant because it's running in windows so background tasks and random fluctuations in the space-time continuum effect the results (that or random task switching...)

Single and Double are usually the same speed or very close. Chances are that the processor's FPU is all double precision inside (actually I think some FPU's are 80 bit floating point inside) and just modifies the precision on the way out for single precision.

0.56
0.51
0.51

amd64 @ 2.8ghz

results are inconsistent but float and double are usually the same?

Andrew

[fyffe555]

0.52
0.65
0.42

amd64 @ 2.8ghz XP64

[joecnc2006]

P4 2.8g dell

I = 0.656000
F = 0.609000
D = 0.610000

[Evodyne]

Death...

800 Mhz PIII:

Integer: 2.153
Float: 2.073
Double: 2.123

Evodyne

[qmas99]

what are all the numbers mean?, is smaller better?

[enigma99501]

T2300 @1.66

.843
.797
.797

[JavaDog]

AMD Athlon MP 2600+ (Dual-CPU)

Time for int test: 0.781
Time for float test: 0.594
Time for double test: 0.609

[Death Adder]

what are all the numbers mean?, is smaller better?

Yes, smaller is better. Basically the speed test just tries to figure out which type of math is faster on a given machine.

From the numbers that people are posting you can see that some machines can do floating point math faster than integer math. That's reversed for some other machines. In general newer machines do better at floating point than older machines.

The point to all of this is to determine whether it is worth it to attempt to use fixed point math in an application. At this point it would appear that it really is not worth it. Also, single and double math seems to be the same speed and so it's probably worth it to use doubles to get the extra precision.

[datacop]

Death Adder's Speed Test.
Please don't touch anything or do anything with the machine until this is done!

Time for int test: 1.822000
Time for float test: 1.532000
Time for double test: 1.593000

Hit a key to end the program

P4 1.41Ghz 1GB Ram...

[tobyaxis]

Here is a new version of the speed testing program. This one allows the pipeline to fill up and as such will give different results than before. This test seems to run a lot better for me which suggests the the P4 pipeline is quite nasty for floating point.

Here are my numbers for the new program (1.8Ghz P4)
Integer: 1.462
Single: 1.311
Double: 1.292

As you can see, the numbers are a lot closer now. This makes floating point worth it.

PS: The attached program was compiled unoptimized and compiled for a 386 so anyone should be able to run it. If compiled optimized the three numbers are basically equal.

Ok, I'm not that bright when it comes to computers and have one question. Are there any specific instructions for the test?
Downloaded and unzipped and waiting to run the test.
This PC is a Lap Top P4 2.0GHz 1GB Ram. Testing a Wirless connection.
The other PC is a P4 H/T 3.2GHz Duel and 1.5GB Ram and upgrading to 4GB Ram in a few months.

[datacop]

Ok, I'm not that bright when it comes to computers and have one question. Are there any specific instructions for the test?
Downloaded and unzipped and waiting to run the test.
This PC is a Lap Top P4 2.0GHz 1GB Ram. Testing a Wirless connection.
The other PC is a P4 H/T 3.2GHz Duel and 1.5GB Ram and upgrading to 4GB Ram in a few months.

just unzip the file and run the test.exe inside....

The rest happens for you automagically.

[tobyaxis]

Just found the text file that explains. Thanks DataCop.

BTW: Just PMed You.
:cheers: