Re: Can extra processing threads help in this case?

Hector Santos <>
Tue, 23 Mar 2010 01:13:58 -0400
Hmmmmm, you mean two threads in one process?

What is this:

     num = Data[num]

Do you mean:

    num = Data[i];

Take the posted code I gave you and change this part:

#include <vector>

// Parameters to play with

#define KIND DWORD // array element type
#define MAX_THREADS 64 // # of threads
DWORD nRepeat = 10; // data access repeats
DWORD nTotalThreads = 2; // # of threads
DWORD size = MAXLONG/6; // ~1.4GB
std::vector<KIND> *data = NULL;
KIND *data = NULL;

// Functions to simulate application work load
// The process data function simply reads the
// memory.

BOOL AllocateData()
    DWORD t1 = GetTickCount();
    _cprintf("- Allocating Data:ram .... ");
     data = new std::vector<KIND>(size);
     data = new KIND[size];
    return TRUE;

void DeallocateData()
    if (bUseFileMap) {
    } else {
       delete data;

#pragma optimize("",off)
void ProcessData()
    KIND num;
    for(DWORD r = 0; r < nRepeat; r++) {
       for (DWORD i=0; i < size; i++) {
          DWORD j = i;
          num = (*data)[j];
          num = data[j];
#pragma optimize("",on)

And run it with no switches and then /t:2 and /t:4.

WATCH it performs for better!

I would also explore it with USE_STD_VECTOR commented out.


Peter Olcott wrote:

The code below apparently proves that you were right all
I ran it as two separate processes and it took a like 16.5
seconds for one instance and 16.55 seconds for two

"Hector Santos" <> wrote in message

Peter Olcott wrote:

Try running your process again using a
std::vector<unsigned int>
Make sure that you initialize all of this to the
subscript of the init loop.
Make sure that the process monitor shows that the amount
of memory you are allocating is the same amount that
total memory is reduced by.
Make sure that you only use 1/2 of total memory or less.
Make a not of the page fault behavior.
I will try the same thing.

You better! :)



#include <stdio.h>
#include <stdlib.h>
#include <vector>
#include <time.h>

#define uint32 unsigned int

const uint32 repeat = 100;
const uint32 size = 524288000 / 4;
std::vector<uint32> Data;

void Process() {
  clock_t finish;
  clock_t start = clock();
  double duration;
  uint32 num;
  for (uint32 r = 0; r < repeat; r++)
    for (uint32 i = 0; i < size; i++)
      num = Data[num];
   finish = clock();
   duration = (double)(finish - start) / CLOCKS_PER_SEC;
   printf("%4.2f Seconds\n", duration);

int main() {
  printf("Size in bytes--->%d\n", size * 4);
  for (int N = 0; N < size; N++)
    Data.push_back(rand() % size);

  char N;
  printf("Hit any key to Continue:");
  scanf("%c", &N);


 return 0;


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