Hi Tomasz, during the benchmark I made sure that all data is in the AB cache (by rerunning multiple times, 1st run after AB start is ~30% slower than subsequent runs), therefore anti-virus should not be the reason. I just checked this by switching AV off on the native machine, the result was the same as before, the VirtualBox is still much faster. I think disk fragmentation is same story, as long as the data is cached it should not have an negative impact ...
Best regards, Markus --- In [email protected], "Tomasz Janeczko" <gro...@...> wrote: > > Hello, > > Disk fragmentation or lack of antivirus on virtual machine. > Most probably your virtual machine > has been freshly created and the "virtual hard drive" file > is not fragmented. > Second reason is anti-virus. Antiviruses intercept all file > accesses (they hook into system libs) > and they are known to slow down file acces > as much as 2-3 times. > > Best regards, > Tomasz Janeczko > amibroker.com > ----- Original Message ----- > From: "markhoff" <markh...@...> > To: <[email protected]> > Sent: Thursday, February 26, 2009 12:42 AM > Subject: [amibroker] AmiBroker speed-up in virtual machine!?!? > > > > > > Hi folks, > > > > I have setup a virtual machine (VirtualBox) to have my real account > > trading with IB separated from other tasks. The strange thing is that > > AB runs in the virtual machine much faster than on the native hardware > > (opposite to my expectation that usually virtual machines have a > > performance penalty), but I have no idea why there is this huge > > difference. > > > > Configuration: > > Native machine: Pentium 4, 2.6GHz, 1.5GB RAM, Windows XP SP3 + usual > > tools like antivirus, firewall etc. > > VirtualBox: 512MB RAM, Windows 2000 SP2, naked installation > > > > AmiBroker directory was copied 1:1 from native machine to virtual > > machine, I checked that all preferences are the same. > > > > Benchmark: Backtesting on Russell 1000 watchlist > > native machine: 32s > > virtual machine: 20s > > > > Wow! It looks like something on the native machine is drastically > > reducing the speed of AB, but I have no clue about the root cause. > > > > Did somebody observe the same? Any ideas? > > > > Thanks in advance and best regards, > > Markus > > > > > > > > > > ------------------------------------ > > > > **** 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 > > > > > > >
