Correction, I meant Level3 shared cache (L1 & L2 are per-core) on i7.
On 2010-06-28 11:32, Tomasz Janeczko wrote: > Hello, > > I would only add to excellent Dennis' explanation, that theoretical 16x > speedup with 4 cores makes one assumption: > that you do not use shared memory extensively. Shared memory (i.e. system > RAM) is slower than single processor core. > Therefore if all cores fight for RAM access, you will not get any speedup if > you run out of on-chip cache. > You would be able to reach 4 times the performance of single core if and only > if entire code and data are on Level-1 (dedicated core) > cache. Even if data are on very fast Level2 on-chip cache (which is shared on > Intel i7) you may not see full theoretical performance. > > Best regards, > Tomasz Janeczko > amibroker.com > > On 2010-06-28 04:09, Dennis Brown wrote: >> Glenn, >> >> You are not hearing what is being said to you. You have a 4 core processor, >> with each core slightly faster than your old machine (clock speed), though >> larger on chip cache, larger main memory and somewhat faster system >> components will benefit your speed. Each core may also do more work in one >> clock cycle due to advanced architecture design. AmiBroker can only use one >> core. However, the other system processes can use the other cores, so they >> will not detract from the AB performance. >> >> You are getting a 4x improvement. That is fantastic! The larger memory is >> likely the main reason you are getting so much better performance. Without >> the memory boost you might see less than 2x improvement. >> >> The likely maximum overall performance improvement of your new system over >> the old, if all cores could be utilized 100% would be about 16x. So you can >> now watch a video or listen to music at the same time as your explore, and >> it is not likely to affect your explore time much. >> >> Be happy! >> >> Dennis >> >> >> >> On Jun 27, 2010, at 8:30 PM, gmorlosky wrote: >> >>> Well.... >>> >>> I loaded a RAMDisk program called Dataram RAM Disk and moved the entire >>> database (333mb) over there. Started AmiBroker and of course it asks where >>> is the data and I point it to the new database. I run the same Explore and >>> guess what....NO faster....It still took 2 minutes and a few seconds to >>> process the Explore. >>> >>> So what do make of that ? >>> >>> Thanks for any help >>> -Glenn >>> >>> >>> --- In [email protected], "gmorlosky"<gmorlo...@...> wrote: >>>> TJ; >>>> >>>> That's a good point about SEEK time - I guess if I were to put the data on >>>> a SSD drive that might cut down some time, but then moving it to a RamDisk >>>> might help even more. >>>> >>>> Thanks >>>> -Glenn >>>> >>>> >>>> --- In [email protected], Tomasz Janeczko<groups@> wrote: >>>>> Hello, >>>>> >>>>> You are dreaming. >>>>> Your new computer is 4 times faster than old one nothing more. >>>>> >>>>> Run some real-world application that is actually doing something serious >>>>> CPU and disk intensive >>>>> (like C++ compiler) and you will see 4 times speed up as well. >>>>> >>>>> You computer may be faster than that on paper or in certain tasks (like >>>>> video decoding, >>>>> because of SSE3 support) but from CPU + disk standpoint it is just about >>>>> 4 times faster >>>>> nothing more. Disk access speeds did NOT improve even 4 times. Your old >>>>> disk may have >>>>> 20 ms and new may have 16 ms access. Not much improvement. Bulk transfer >>>>> rates >>>>> do NOT matter at all because with the exception of copying 1GB file disk >>>>> must >>>>> SEEK and time is spent on seeking rather than transfering data. >>>>> >>>>> Best regards, >>>>> Tomasz Janeczko >>>>> amibroker.com >>>>> >>>>> On 2010-06-27 18:06, gmorlosky wrote: >>>>>> Hi TJ; >>>>>> >>>>>> I was saying overall my new system runs other application what seems >>>>>> like 50 times faster, but as you pointed out I am only getting 4 times >>>>>> faster compared to that old system. >>>>>> >>>>>> Something isn't right here, it should be a lot faster. >>>>>> >>>>>> Any other thoughts ? >>>>>> >>>>>> Thnaks >>>>>> >>>>>> >>>>>> --- In [email protected], Tomasz Janeczko<groups@> wrote: >>>>>> >>>>>>> Hello, >>>>>>> >>>>>>> 2 minutes vs 8 minutes ? That is 4 times not 50% as you say. >>>>>>> >>>>>>> Your new system runs this exploration 4 times faster than old one. >>>>>>> That is actually faster than one could expect. >>>>>>> >>>>>>> Best regards, >>>>>>> Tomasz Janeczko >>>>>>> amibroker.com >>>>>>> >>>>>>> On 2010-06-27 14:26, gmorlosky wrote: >>>>>>> >>>>>>>> I am very disappointed in the speed I am getting running an Explore in >>>>>>>> AmiBroker 5.20. Here is my example: >>>>>>>> >>>>>>>> Both units are running the same 32 bit version of Amibroker 5.20, >>>>>>>> running the same Explore I created, with no other software other than >>>>>>>> basic antivirus running. >>>>>>>> *********************************** >>>>>>>> Old system (about 7 years): >>>>>>>> Pentium D (single core) 2.4 mhz, 1 gig memory 233 mhz, 5400 rpm drive, >>>>>>>> Windows XP Pro >>>>>>>> >>>>>>>> Results of Explore (5500 sysmbols): >>>>>>>> CPU usage 100%, 8 minutes 5 seconds >>>>>>>> *********************************** >>>>>>>> New system (about 2 months): >>>>>>>> i7-930 (quad core) 2.6 mhz, 6 gig memory 1600 mhz, 7200 high rpm >>>>>>>> drive, Windows 7 64 bit >>>>>>>> >>>>>>>> Results of Explore (5500 sysmbols): >>>>>>>> CPU usage 12%, 2 minutes 3 seconds >>>>>>>> *********************************** >>>>>>>> Why so stinking slow ??? when the new system is roughly 50 times >>>>>>>> faster in overall processing ??? >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> ------------------------------------ >>>>>>>> >>>>>>>> **** 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/ >>>>>> >>>>>> 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/ >>> >>> 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/ >> >> 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/ > > Yahoo! Groups Links > > > >
