Also your L2 cache only being 256kb could be holding you back quite a bit, the unit is probably swapping stuff on and off the hard drive like crazy as the unit progresses along, since the L2 cache is small by todays new standards.
I would regard my knowledge of memory caches (L1, L2, L3) as being pretty sub-standard, to the point that normally, I would not comment. In this case I feel I should. I could be quite wrong, but isn't there a big flaw in what you are saying? Isn't the basic benefit of these caches their speed? They are simply *faster* than *main memory* - ie nothing to do with disk swapping. If a commonly executed set of instructions can fit in cache it can be executed much faster there, than if it has to reside in main memory. If there is sufficient main memory there shouldn't be any disk swapping, irrespective of whether or not there is sufficient cache.
If I'm wrong, I'll quite happily stand corrected.
You are correct, as long as the WHOLE workunit fits into the L2 cache, then the swapping isn't a problem, but if the unit does not fully fit into the L2 cache then it swaps the parts it's working on back and forth to and from the much slower hard drive. Back in the day we used to call pc's with less than 512k of L2 cache "Celerons" or Semprons" depending on who made, them, Intel or AMD.
Some projects have gotten their programming to use the L3 cache now too, but I don't remember which ones anymore. Most newer pc's do have much larger L3 cache's and on those projects that can use it the units do not swap hardly at all.
You are correct, as long as the WHOLE workunit fits into the L2 cache, then the swapping isn't a problem, but if the unit does not fully fit into the L2 cache then it swaps the parts it's working on back and forth to and from the much slower hard drive.
Nope.
Work does not swap to the hard drive unless it runs out of RAM. Nothing to do with fitting in the cache, at any level whatever.
Thanks Gary.
1) I checked my anti-virus settings : it doesn't scan the files permanently (just once a week), it only checks the incoming files or datas. Then it is not the issue.
2) sorry for not managing correctly the communication tools of BOINC ("edit" and others). I have to practice...
3) I changed some limiting values :
- disk space increased from 100Go to 5OOGo (I can increase again if usefull)
- when computer is used : max memory set to 70%
- when computer is not used : max memory set to 90%
In the old UNIX systems, when memory was expensive, you had a small RAM and you installed at start a swap space double that RAM. Swap is useful when the RAM is used totally and it serves as a RAM on disk, clearly slower. Now RAMs are huge (I have a 24 GB RAM on my Windows 10 PC) and swap is rarely used.
Tullio
In the old UNIX systems, when memory was expensive, you had a small RAM and you installed at start a swap space double that RAM. Swap is useful when the RAM is used totally and it serves as a RAM on disk, clearly slower. Now RAMs are huge (I have a 24 GB RAM on my Windows 10 PC) and swap is rarely used.
Tullio
Thanks Tullio. I won't consider this parameter then.
JF
RE: RE: Also your L2
)
You are correct, as long as the WHOLE workunit fits into the L2 cache, then the swapping isn't a problem, but if the unit does not fully fit into the L2 cache then it swaps the parts it's working on back and forth to and from the much slower hard drive. Back in the day we used to call pc's with less than 512k of L2 cache "Celerons" or Semprons" depending on who made, them, Intel or AMD.
Some projects have gotten their programming to use the L3 cache now too, but I don't remember which ones anymore. Most newer pc's do have much larger L3 cache's and on those projects that can use it the units do not swap hardly at all.
RE: You are correct, as
)
Nope.
Work does not swap to the hard drive unless it runs out of RAM. Nothing to do with fitting in the cache, at any level whatever.
Thanks Gary. 1) I checked my
)
Thanks Gary.
1) I checked my anti-virus settings : it doesn't scan the files permanently (just once a week), it only checks the incoming files or datas. Then it is not the issue.
2) sorry for not managing correctly the communication tools of BOINC ("edit" and others). I have to practice...
3) I changed some limiting values :
- disk space increased from 100Go to 5OOGo (I can increase again if usefull)
- when computer is used : max memory set to 70%
- when computer is not used : max memory set to 90%
But for "espace d'échange (swap)" I do not know what to do with this, just because I do not understand what it is. At the moment, it is set to 75%.
I guess that now, I have to measure the times for equivalent tasks to see if something has been improved.
Cheers and thanks again.
JF
In the old UNIX systems, when
)
In the old UNIX systems, when memory was expensive, you had a small RAM and you installed at start a swap space double that RAM. Swap is useful when the RAM is used totally and it serves as a RAM on disk, clearly slower. Now RAMs are huge (I have a 24 GB RAM on my Windows 10 PC) and swap is rarely used.
Tullio
RE: In the old UNIX
)
Thanks Tullio. I won't consider this parameter then.
JF