Working out download rate

[Lorddalron]

Little bit of help needed please:

Connection = 33.08Mbps
File size = 124KB

How long to download and to (3sf)?

Is it the file size / speed?

Am i right in thinking 33.08Mbps = 33080000 bits (or 33.08 x 10n6), &
124kb = 1015808 bits

So 1015808 / 33080000 = 0.0307 seconds = 0.01seconds (3sf) or just 0.03?

 

[djkav]

0.03s sounds about right.

33mbps is around 4.125mb/s

 

[Orcvader]

I'm assuming 33.08 is what speed tests reports, which is in bits (b), not bytes (B). In bytes that would be 4.135 mB/s or 4234.24 kB/s (1024 B = 1 kB).

Assuming 124 is also in bytes, then it would take 0.0293 (3 s.f.) seconds to transfer.

 

[Lorddalron]

0.03s sounds about right.

33mbps is around 4.125mb/s

Thanks,
out of curiosity, how did you then work out 33mbps = 4.125mbps?

 

[Orcvader]

Thanks,
out of curiosity, how did you then work out 33mbps = 4.125mbps?

1 byte = 8 bits

 

[djkav]

Thanks,
out of curiosity, how did you then work out 33mbps = 4.125mbps?

1 byte = 8 bits

Yup, basically it's 33,000 / 8 = 4125.

I always use mb, kb, gb for bytes. I guess its from my old school days in the 1980s.

I tend to use mbit, gbit, kbit for bits.

 

[Lorddalron]

I'm assuming 33.08 is what speed tests reports, which is in bits (b), not bytes (B). In bytes that would be 4.135 mB/s or 4234.24 kB/s (1024 B = 1 kB).

Assuming 124 is also in bytes, then it would take 0.0293 (3 s.f.) seconds to transfer.

yea, the transmission speed is indeed bits per second, not bytes and the file size is KiloBytes.

So where am i getting 0.0307 rather than 0.0293?

 

[Orcvader]

You did:

33.08Mbps = 33080000 bits (or 33.08 x 10n6)

Which is wrong, you left it in bits and you did 1 kilobit =1000 bit instead of 1 bit =1024 kilobit.

Converting it to megabytes, then turning it into kilobytes will give 4234.24 kB.

124 kB / 4234.24 kB = 0.029285... or 0.0293 in 3 sig figs.

 

[Lorddalron]

You did:



Which is wrong, you left it in bits and you did 1 kilobit =1000 bit instead of 1 bit =1024 kilobit.

Converting it to megabytes, then turning it into kilobytes will give 4234.24 kB.

124 kB / 4234.24 kB = 0.029285... or 0.0293 in 3 sig figs.

Of course, storage = 1024 and transmission - 1000

So what i should do is:

33.08 / 8= 4.135 * by the storage rate of 1024, not 1000 which = 4234.24

then the file size of 124 KB / 4234.24 = 0.029285 (0.0293) 3SF

 

[Orcvader]

I believe with transmission it's still 1024, since computers work in base 2 not base 10.

 

[Lorddalron]

I believe with transmission it's still 1024, since computers work in base 2 not base 10.

I dont think so. What i mean is, and what I think djkav was eluding to is:

In regards to data storage, 1kB(kiloByte) = 1024Bytes and in transmission terms, 1kb (kilobit) = 1000kb =1 Megabit.

 

[Orcvader]

I don't think he was...?

The only time I've seen 1=1000 used is with marketting. Even speed tests uses 1 kbit = 1024 bit.

 

[Method0ne]

I believe with transmission it's still 1024, since computers work in base 2 not base 10.

Correct, in all computing terms other than marketing, 1024 is the number used.

 

[moogle]

0.0307s

Data rates have always been in powers of 10.

 

[Lorddalron]

0.0307s

Data rates have always been in powers of 10.

So as i originally said then.

im just confused im doing my course through OU and had a face to face class yesterday and my module teacher, a maths teacher by trade says its 1024 for storage and 1000 for transmission.

What do you mean for marketing?

 

[Orcvader]

I just had a check, seems data rates is measured with 1000.

Well, that just confuses things. I don't know anymore .

EDIT: Seems you was right the first time: http://www.wolframalpha.com/input/?...-&a=UnitClash_*mb/s.*MegabitsPerSecond.dflt--

 

[moogle]

So as i originally said then.

im just confused im doing my course through OU and had a face to face class yesterday and my module teacher, a maths teacher by trade says its 1024 for storage and 1000 for transmission.

What do you mean for marketing?

Marketing as in they use mbits instead of megabytes for impressive numbers, but it's really because that's what is used for data rates so it's not really used for that reason imo.

 

[Lorddalron]

Thanks for all the help. It was more confusion than doubt with my replies but it looks like we got things sorted.

 

[bledd]

If you already know the maths side of it and how it works, just use this

http://www.numion.com/calculators/time.html

 

[Lorddalron]

If you already know the maths side of it and how it works, just use this

http://www.numion.com/calculators/time.html

i came across that site but it doesn't show any results above 512Kbps