# Thread: Bandwidth Conversion

1. Aspiring Evangelist
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## Bandwidth Conversion

What are the formulas to convert Mbps/Kbps to megabytes?

2. Aspiring Evangelist
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For a rough idea, take the number of Mbps * .324 for the number of gigabytes.

ie: if your average transfer is 1 Mbps, 1 *.324 = 324 gigabytes

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4. Aspiring Evangelist
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Thanks...

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6. Web Hosting Evangelist
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Originally posted by JG
For a rough idea, take the number of Mbps * .324 for the number of gigabytes.

ie: if your average transfer is 1 Mbps, 1 *.324 = 324 gigabytes
I always do:

(2^20 / 8 * 60 * 60 * 24 * 30) / 2^30

which equals 316.406. Where does the 324 number come from? On a 31 day month, it is 326.953...

Of course, bear in mind when converting, that 1 Mbps at the 95th percentile is not an average. Where I work we tend to see a 1.85:1 peak to off-peak ratio of total traffic in Mbps. Keeping that in mind, if you buy a server with a 10 Mbps full pipe, and hope to do anything over about 7 Mbps average, you'll be losing packets at peak time. A peak near 9.5 Mbps will result in an off-peak amount of just under 5 Mbps. It gets more complicated when you actually get Calculus involved...

\$0.02

7. Web Hosting Master
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the 324gb comes if 10^9 instead of 2^30. Megabit is 10^9, gigabyte (as defined by your hard drive manufacturer) is 10^9, so many people use gigabyte as 10^9 instead of the true 2^30.

Regardless, it never explains how these cons come up claiming 1mbps 340gb, 350gb, 360gb, even seen 380gb once .

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the best one I've got is at http://www.valkaryn.net/bwcalc/

Naseer

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Originally posted by Goni
the best one I've got is at http://www.valkaryn.net/bwcalc/

Naseer
my new favorite link j/k but its awesome yes

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b = bit = 1
B = byte = 8 bits
k = 1024 bytes
M = 1048376 bytes

1kB/s = 1024 B/s = 8192 b/s = 0.008192 Mb/s

1Mb/s = 1048276 b/s = 131034.5 B/s = 131.0345 kB/s
Last edited by HostingDotExpress; 10-18-2002 at 04:08 AM.

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12. Junior Guru Wannabe
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I suggest using mrtg (http://people.ee.ethz.ch/~oetiker/webtools/mrtg/) for megabit measuring and IOG (http://www.dynw.com/iog/) for gb measuring...

GB's and megabits are two different beasts, and any conversion forumula is fraught with mathematial rounding errors based on how the original data was collected/stored. This is espeically true if you try to convert megabits to GB's from the default install of MRTG which uses lossy compression of the measured data stream over time (ie you could be giving bandwidth away to your customers).

Darin

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Originally posted by porcupine
the 324gb comes if 10^9 instead of 2^30. Megabit is 10^9, gigabyte (as defined by your hard drive manufacturer) is 10^9, so many people use gigabyte as 10^9 instead of the true 2^30.

Regardless, it never explains how these cons come up claiming 1mbps 340gb, 350gb, 360gb, even seen 380gb once .
Thank you for pointing that out. I'm a bit old-school, I wasn't even aware someone (apparently for marketing reasons) started using a base-10 conversion in the past. I'll keep using the smaller numbers. As a host, that means I'll never be disappointed, and my customers will always be happy. 380? Geez, are they using an uncalibrated slide-rule or something?

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Originally posted by BobFarmer

Thank you for pointing that out. I'm a bit old-school, I wasn't even aware someone (apparently for marketing reasons) started using a base-10 conversion in the past. I'll keep using the smaller numbers. As a host, that means I'll never be disappointed, and my customers will always be happy. 380? Geez, are they using an uncalibrated slide-rule or something?
Uncalibrated cranium's i believe , its plain false advertising, as is anything over 330gb, personally a only ever claim 300, 316, or 324gb, depending on the question asked, i'll probably settle at 320gb though just because its so neutral between the two.

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Of course, there's the pure fact that if you convert any capped Mbps line to GB transferred, you won't see anything near 300+ GB per Mbps. A better translation is around 200 GB per 95% Mbps. Unless you are a glutton for punishment and love packet loss, you won't be "averaging" your max transfer.

\$0.02

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Originally posted by BobFarmer
Of course, there's the pure fact that if you convert any capped Mbps line to GB transferred, you won't see anything near 300+ GB per Mbps. A better translation is around 200 GB per 95% Mbps. Unless you are a glutton for punishment and love packet loss, you won't be "averaging" your max transfer.

\$0.02
Thats nowhere near true.

If you pack on a healthy amount of asian/european customers/oriented websites, along with austrailian ones, you may well find that because bandwidth usage has almost a sin wave pattern, getting more bandwidth used by a different timezone is like adding another sin wave with a different offset, making your graphs almost flat. Granted that is relatively difficult to do, but some people have extremely "spikey" bandwidth graphs, and then i've seen a few (customer ones even) that are almost completely flat at many different levels (from like 100k/s to 10mbps).

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http://cgi.ebay.com/ws/eBayISAPI.dll...tem=2061140830

But this ebay item says it's 1.5mbps and the data transfer is 120gb. So divide 120 by 1.5 and yo get 80GB per mpbs. That's not right??

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Originally posted by porcupine

Thats nowhere near true.

If you pack on a healthy amount of asian/european customers/oriented websites, along with austrailian ones, you may well find that because bandwidth usage has almost a sin wave pattern, getting more bandwidth used by a different timezone is like adding another sin wave with a different offset, making your graphs almost flat. Granted that is relatively difficult to do, but some people have extremely "spikey" bandwidth graphs, and then i've seen a few (customer ones even) that are almost completely flat at many different levels (from like 100k/s to 10mbps).
I'm not sure if I'd say "that's nowhere near true." You're right, there are plenty of things, in theory, that you can do to get more out of your bandwidth. I've been operating thousands of servers over 8 years, and am going on that information. The law of averages tends to win out in the end. We do see a double-bubble, but the 6 hour block from 11am EST to 5pm EST doesn't get much competition. Also, in the webhosting market, it isn't very easy to decide where your traffic comes from. If you are running a network, and want to expand your network to Asia and sell pipes, you will have better luck. Like I said, I just like to ensure nobody is disappointed. That goes not only for conversion expectations, but also for quality of bandwidth.

\$0.02

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its easy to market your bandwidth, just get advertising space on websites written in other languages from the countries you want bandwidth from (Based on timezone), make sure you get your advertising translated over of course also, that tends to even it out, only problem being then... the laguage barrier between you and your customers.

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