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Hello,
It was explained in the past. My test have shown that single core using
array arithmetic
fully saturates RAM bandwidth and single core already waits for RAM,
thus adding more cores
makes AFL running slower, not faster if data do not fit into CPU on-chip
cache.
Using more than 1 core makes sense only if many cores do not access lots
of data in RAM
(more than cache size) or when floating point units do operations that
take many cycles (like trigonometric
functions). For simple operations like
addition/subtraction/multiplication the CPU is much
faster than RAM and needs to wait for the memory to deliver data.
Best regards,
Tomasz Janeczko
amibroker.com
zozuzoza wrote:
> Thanks, how about the CPU issue? Why Amibroker cannot utilize the 2 CPUs at full extent?
>
>
> --- In amibroker@xxxxxxxxxxxxxxx, Tomasz Janeczko <groups@xxx> wrote:
>
>> Hello,
>>
>> The RAM usage in the preferences is a maximum limit.
>> If AmiBroker does not need to use that maximum for that
>> particular optimization it won't use that limit.
>> AmiBroker is coded efficiently and conserves memory, so many problems
>> can be fully
>> solved without using large amounts of memory.
>>
>> Best regards,
>> Tomasz Janeczko
>> amibroker.com
>>
>> zozuzoza wrote:
>>
>>> Hi,
>>>
>>> Amibroker cannot use more than 440 MB RAM even if I set the max. Megabytes to 1000 in the preferences.
>>>
>>> Also, the cumulative CPU usage cannot be more than 100% in a core 2 duo processor computer, e.g. CPU1=10% and CPU2=90%. The operating system is a 64 bit one and I am expecting to use 100% of CPU1 and 100% of CPU2 at the same time if Amibroker is requested to perform heavy calculations.
>>>
>>> Do you have an idea about the above limitations?
>>>
>>> Thank you.
>>>
>>> Br,
>>> Zozu
>>>
>>>
>>>
>>> ------------------------------------
>>>
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>
>
>
>
> ------------------------------------
>
> **** IMPORTANT PLEASE READ ****
> This group is for the discussion between users only.
> This is *NOT* technical support channel.
>
> TO GET TECHNICAL SUPPORT send an e-mail directly to
> SUPPORT {at} amibroker.com
>
> TO SUBMIT SUGGESTIONS please use FEEDBACK CENTER at
> http://www.amibroker.com/feedback/
> (submissions sent via other channels won't be considered)
>
> For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG:
> http://www.amibroker.com/devlog/
>
> Yahoo! Groups Links
>
>
>
>
>
------------------------------------
**** IMPORTANT PLEASE READ ****
This group is for the discussion between users only.
This is *NOT* technical support channel.
TO GET TECHNICAL SUPPORT send an e-mail directly to
SUPPORT {at} amibroker.com
TO SUBMIT SUGGESTIONS please use FEEDBACK CENTER at
http://www.amibroker.com/feedback/
(submissions sent via other channels won't be considered)
For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG:
http://www.amibroker.com/devlog/
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