A supplementary remark: I did some search on the web and got the impression that the low VFS performance might have HW reasons. If it is really so, then we don't have other option, but to accept it. Any thoughts?
Jan Slodicka ----- Original Message ----- From: "Jan Slodicka" <[EMAIL PROTECTED]> > Hello > > I have got some interesting numbers when benchmarking loading of large jpeg > files. > > Jpeg size = 7.13 MB > > Loading jpeg (Tungsten/t, MMC card): > - from the card 28 secs > - from RAM 8 secs > > The same card used in Nokia 3650: > Loading the same jpeg takes 18 secs. (The same loader used.) > > Copying the same jpeg file on T/t: > card -> card = 85 secs > card -> RAM = 21 secs > > Some technical details: > Jpeg loader uses 4K buffer when reading from the card. Previous tests showed > that this is a quite good compromise - larger buffers bring negligible > gains. > > File copy is realized in 16K blocks. Also, a few sporadic tests indicated > that larger buffer does not bring too much. > > Nokia 3650 is ARM 9, 104 MHz. > T/t is OMAP 1510 with 144 MHz. > Processors are not exactly my area, but I would say that T/t should be a bit > faster. (For the jpeg loading: Work done in M68K mode is negligible > compared to the work done in the ARM mode.) > > We could not benchmark RAM loading on Nokia (because the jpeg was too big), > but this was not my primary interest. Anyway, in case that the eventual > discussion would require it, I can do that later. > > For me the basic question is: Why the card reading is so slow on T/t, or > what can be done to speed it up? > > Arguments of the kind that Palm must be prepared to the drive removal may > sound logically when comparing to Nokia (where the card exchange can be done > only in the switched off state), but I am to 90% sure that we would get > similar differences between Palm and PocketPC (they are both in the same > situation). > > Can anybody give me some explanation? -- For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/support/forums/
