Coalwater, The 'granularity' is the 'slice' of time used for the calculations (this could be either actual time slots or 'elapsed time'). The smaller the granularity the larger the variations will appear in a graph. Using the previous example if the calculation was done with a once a second granularity (I will presume that a 1400 Byte chunk arrives each 100 ms.) which would mean that there would have been 1400 + 1400 * 10 chunks = 15,400 Bytes in the first second = 15,400 Bytes per second as the first point; but the second point would only have 1400 * 10 = 14,000 Bytes/second, a much lower difference.
On Feb 28, 6:53 pm, Mohammad AbuShady <[email protected]> wrote: > I see, thanks a lot, and for your question about where the speed is being > show, it's both in the download window (firefox download window) and also a > network speed monitor over the whole system, of course they don't show the > same numbers but they both show the small increase in the start, and I don't > really know what 'granularity' means. > > ~Coalwater~ > > On Mon, Mar 1, 2010 at 1:33 AM, KwikOne <[email protected]> wrote: > > You did not indicate "where" your download speed is being shown/ > > calculated, nor the time > > granularity used. Quite often the speed spike are not really spikes > > (especially when first > > starting the download) because of the way the download speed is being > > calculated and > > as time goes on the download speed stays constant, or it will drop off > > then stay constant. > > Think of it this way (note the figures are just approximates as > > illustration only with rounding)... > > 1) download requested from server > > 2) first bit of data arrives; calculated speed is roughly amount of > > data / 1 ms. (smallest granularity) > > = very high speed (1000 times amount of data) > > (example - first chunk is 1400 Byte, this would give approx > > 1,400,000 Byte/sec rate) > > 3) next bit of data arrives; calculated speed is roughly total amount > > of data / (time from first bit > > to second bit) = lower speed (unless the server is close enough > > that you have < 1ms time) > > (example - second chunk 1400 Byte arrives 100 ms later which would > > give approx > > 2800 Byte for 100 ms. = 28,000 Byte/sec). > > 4) next bit of data arrives (example 1400 Byte 100 ms later which > > calculates out to > > 4200 Byte in 200 ms. = 21,000 Byte/sec). > > and so on... get the picture (it all depends upon how the calculations > > are done)? > > Notice how the rate is dropping off when in actual fact in this > > example it is actually 14,000 Byte/sec. > > > On Feb 22, 7:37 pm, Coalwater <[email protected]> wrote: > > > Well i noticed that i when ever i start a download, the download speed > > > starts with a very high speed spike in the beginning that could reach > > > up to 3x of my bandwidth, and last for like 3 to 10 secs then starts > > > to gradually drop till it reaches my usual expected download speed, > > > this isn't really a problem but i would really like to understand it > > > from the networks point of view, how does it get past the ISP limit > > > even if for a very short period of time, because i might think of > > > using it to my advantage somehow if i understand it, Hope some > > > networks guy around here could explain to me :D > > > oh and it doesn't depend on the connection type nor the operating > > > system, i saw this happen on cable connection and mobile broadband, > > > windows and ubuntu so it doesn't have any thing to do with those > > > differences.. oh and it works also with both normal single connection > > > download and download accelerators that use multipart downloading > > > -- > > You received this message because you are subscribed to the Google Groups > > "Computer Tech Support" group. > > To post to this group, send email to > > [email protected]. > > To unsubscribe from this group, send email to > > [email protected]<computer-tech-support%[email protected]> > > . > > For more options, visit this group at > >http://groups.google.com/group/computer-tech-support?hl=en. -- You received this message because you are subscribed to the Google Groups "Computer Tech Support" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/computer-tech-support?hl=en.
