By default is it set to half of available physical memory. 409MB should be just fine in your case.
Best regards, Tomasz Janeczko amibroker.com ----- Original Message ----- From: "danielwardadams" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Thursday, May 15, 2008 3:26 PM Subject: [amibroker] Re: Dual-core vs. quad-core > Tomasz, > I'm sure you've answered this before but I couldn't find it. How do > you best determine AB internal cache size? I see mine is set at > 409MB. Other database settings are 10000 symbols (even though I never > have over 200-300 in my database), number of bars to load is 1000, > limiting number of saved quotations isn't checked. > > I'm running an Athlon 3200+ processor, Windows XP SP2, and AB 5.09.0. > I have 2GB and rarely use much over half of it. I'm mostly interested > in speed while optimizing formula parameters with Quotes Plus EOD > data using the Intelligent Optimizer (IO). I have one long run on the > weekends that I'd be (very) interested in speeding up > > Thanks, > Dan > > > --- In [email protected], "Tomasz Janeczko" <[EMAIL PROTECTED]> > wrote: >> >> Hello, >> >> As for 1) you would do better by increasing AB internal cache in > preferences. >> >> Best regards, >> Tomasz Janeczko >> amibroker.com >> ----- Original Message ----- >> From: "akerstkh" <[EMAIL PROTECTED]> >> To: <[email protected]> >> Sent: Wednesday, May 14, 2008 6:09 PM >> Subject: [amibroker] Re: Dual-core vs. quad-core >> >> >> > Good morning, >> > >> > Just to share some experience in Optimizing the Speed... Mainly > in >> > compiling of data with the ATC instruction with loops... >> > >> > 1) Created a RAM Disk of 1G. Copy the Data Folder to the RAM > Disk >> > and then use the Data in the RAM Disk do the compiling. (Only > worth >> > doing if compile a couple of times a day.. It cut down from 16 > mins >> > to 11 mins. ) >> > >> > 2) MOVE the Data Folder to another physical drive. Then perform > the >> > disk defragmenter on the Amibroker Drive a couple of times. Then >> > MOVE the Data Folder back to the original position. >> > >> > 3) Chop Down the number of bars in Data Base. >> > >> > >> > >> > >> > The Current system is Intel Core 2 @2.13GHz with 4G RAM. >> > >> > Yet to try is to upgrade the system with RAID4 with 4 Disks and >> > Q9450. >> > >> > Is there any one can comment on the experience with RAID5 > system? >> > >> > >> > Best Regards >> > KH Tang >> > >> > >> > --- In [email protected], Dennis Brown <see3d@> wrote: >> >> >> >> It also makes me wonder if there is another possibility for > speed >> >> optimization. I run more than 1 RT chart at the same time to > get >> >> multi-timeframe results that are not possible in a single chart - > - >> > then >> >> pass results between the charts. It seems as though parallel >> >> processing would be possible between multiple "live" indicator >> > mode >> >> charts. Maybe I will have to get the 8 core system next time :) >> >> >> >> Best regards, >> >> Dennis >> >> >> >> On May 14, 2008, at 10:13 AM, dloyer123 wrote: >> >> >> >> > Interesting result. It is reasonable to expect newer and > future >> >> > processors to have even larger caches. 6MB on the E8400 >> >> > >> >> > So, there may be an opportunity to get useful work out of the >> > other >> >> > cores during long optimization runs. Maybe large "work units" >> > such >> >> > as symbols lists or entire optimization passes to minimize sync >> >> > overhead? >> >> > >> >> > That also implies that user formula code could be optimized if > we >> >> > group array access together, ie use a result right after it is >> >> > created, so it can be pulled out of cache, rather than wait > until >> >> > later in the code. I will have to try this... >> >> > >> >> > >> >> > >> >> > --- In [email protected], "Tomasz Janeczko" <groups@> >> >> > wrote: >> >> >> >> >> >> Hello, >> >> >> >> >> >> I just run the same code on my relatively new notebook (Core > 2 >> > Duo >> >> > 2GHz (T7250)) >> >> >> and the loop takes less than 2ns per iteration (3x speedup). > So >> > it >> >> > looks like the data sits entirely inside the cache. >> >> >> This core 2 has 2MB of cache and thats 4 times more than on >> > Athlon >> >> > x2 I got. >> >> >> >> >> >>> If what you say is true, and one core alone fills the memory >> >> >>> bandwidth, then there should be a net loss of performance > while >> >> >>> running two copies of ami. >> >> >> >> >> >> It depends on complexity of the formula and the amount of > data >> > per >> >> > symbol >> >> >> you are using. As each array element has 4 bytes, to fill 4 > MB of >> >> > cache >> >> >> you would need 1 million array elements or 100 arrays each > having >> >> > 10000 elements >> >> >> or 10 arrays each having 100K elements. Generally speaking > people >> >> > testing >> >> >> on EOD data where 10 years is just 2600 bars should see speed > up. >> >> >> People using very very long intraday data sets may see >> > degradation, >> >> > but >> >> >> rather unnoticeable. >> >> >> >> >> >> Best regards, >> >> >> Tomasz Janeczko >> >> >> amibroker.com >> >> > >> >> > >> >> > ------------------------------------ >> >> > >> >> > Please note that this group is for discussion between users > only. >> >> > >> >> > To get support from AmiBroker please send an e-mail directly to >> >> > SUPPORT {at} amibroker.com >> >> > >> >> > For NEW RELEASE ANNOUNCEMENTS and other news always check > DEVLOG: >> >> > http://www.amibroker.com/devlog/ >> >> > >> >> > For other support material please check also: >> >> > http://www.amibroker.com/support.html >> >> > Yahoo! Groups Links >> >> > >> >> > >> >> > >> >> >> > >> > >> > >> > ------------------------------------ >> > >> > Please note that this group is for discussion between users only. >> > >> > To get support from AmiBroker please send an e-mail directly to >> > SUPPORT {at} amibroker.com >> > >> > For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG: >> > http://www.amibroker.com/devlog/ >> > >> > For other support material please check also: >> > http://www.amibroker.com/support.html >> > Yahoo! Groups Links >> > >> > >> > >> > > > > ------------------------------------ > > Please note that this group is for discussion between users only. > > To get support from AmiBroker please send an e-mail directly to > SUPPORT {at} amibroker.com > > For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG: > http://www.amibroker.com/devlog/ > > For other support material please check also: > http://www.amibroker.com/support.html > Yahoo! Groups Links > > >
