Articles: CPU
 

Bookmark and Share

(43) 
Pages: [ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 ]

In this respect, we decided to try figuring out how the 64bit and 32bit applications work in Windows XP 64-Bit Edition. Since there were no fully-fledged 64bit applications and benchmarks for Athlon 64 FX-51 to be tested with 64bit Windows code, we had to resort to synthetic tests. We used three small utilities compiled for 64bit and 32bit Windows versions. Among them are:

  • DivX Encoder: this benchmark measures the video stream encoding speed;
  • Mini-GZIP: this benchmark implements a well-known data compression algorithm;
  • RSA: this is a set of tests measuring the performance of standard cryptographic algorithms.

The initial code for all three benchmarks was preliminarily optimized for AMD64 architecture. Therefore, the results you are going to see right now represent a kind of ideal case. Nevertheless, they still allow to evaluate how big the maximum performance boost will be in a system with an Athlon 64 and Athlon 64 FX and the programs recompiled for x86-64 command system. Also note that the algorithms used as a basis for all the above described benchmarks do not work with large data packs. That is why you shouldn’t drive any conclusions about the complex performance of the 64bit AMD processors in 64bit Windows operation system.

So, the table below sums up the results of the three above mentioned benchmarks:

 

Win32, 32-bit .exe

Win64, 32-bit .exe

Win64, 64-bit .exe

Minigzip

Zip, sec

9.6

9.6

4.3

Unzip, sec

0.7

0.7

0.3

RSA

AES-128 Encrypt, sec

3.5

3.5

2

AES-128 Decrypt, sec

3.6

3.5

2.5

Triple-DES Encrypt, sec

6.9

7

6.6

Triple-DES Decrypt, sec

6.9

7

6.6

RC4 Encrypt, sec

2.3

2.3

2

RC4 Decrypt, sec

2.3

2.4

2

RSA Encrypt (key size = 4096, number of primes = 2), sec

4.6

4.5

1.4

RSA Decrypt (key size = 4096, number of primes = 2), sec

14.1

14

3.1

SHA-1 Digest, sec

3.8

3.8

3.5

DivX

DivX, sec

8.9

9.1

7.6

As we see, the performance may grow up quite tangibly as soon as we start using the advantages of the 64bit architecture of the new AMD CPUs. The simple recompilation in certain cryptographic tasks may result into not the percentage of growth but times. Moreover, as we see, the 32bit code processing does not get any slower on a 64bit system, which is exactly one of the advantages of the x86-64.

However, it is not for nothing that we said: we are talking about the performance in applications with minimal memory addressing operations. The thing is that the recompilation of 32bit addresses, which are used by 32bit applications, may lead to performance lowering in a 64bit system. To prove this point we would like to offer you the results obtained in Stream benchmark compiled for 32bit as well as for 64bit Windows XP version:

 

Win32, 32-bit .exe

Win64, 32-bit .exe

Win64, 64-bit .exe

Copy (MB/s)

5453

5342

5299

Scale (MB/s)

5439

5370

5395

Add (MB/s)

5319

5253

5304

Triad (MB/s)

5354

5277

5298

And this is where a really unpleasant surprise is waiting for us: 64bit addressing slows down operations with the memory a little bit, while the use of 32bit code in 64bit Windows XP slow these operations even more. Although the performance reduction in the synthetic Stream test should hardly be regarded as critical: the memory speed difference for 32bit code used in 32bit OS or 64bit OS makes only 2%. But this is just the beginning.

 
Pages: [ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 ]

Discussion

Comments currently: 43
Discussion started: 09/23/03 10:36:05 AM
Latest comment: 12/03/06 07:45:26 AM

View comments

Add your Comment