Whats the REAL truth about internet speeds

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Sawtooth
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Whats the REAL truth about internet speeds

Post by Sawtooth »

So I am still trying to understand internet speeds after all these years. And I am pretty computer tech save, even did tech support for Microsoft Win95 pre release and post. I was on BBs that had internet back in the mid 1980's where you had to pay either by the minute or by the hour, whatever you consumed in the immediate time or on a monthly basis. (web pages weren't really even a thought back then, we barely knew what to do with a mouse!)

Look, here's what I am really trying to figure out-

I know that x + y = c. If you have DSL then their claim of say 100 mb/s = 50 upload and 50 download, and you are really only going to see 25 either way on the best hour of the day.

I know that with cable, you are going to see maximum speeds at 4:00 am when no one else is on. If it is prime time, you will be lucky to read your email.

But here is whats really bugging me and I am trying to understand it better-
I am on fiber optic, 1 gb internet. I can do a speed test and see 900+ download and even 1000+ upload. But at the same time I am seeing these speeds through 3 different speedtest sites, and I backed up my 4 gb pictures to my cloud storage, it takes 20 minutes to complete.

So, lets say I am actually transferring data at 500mb/s. I want to transfer 5 gb of data. these numbers would suggest that my file transfer would only take 10 seconds. but it actually takes 15+ minutes.

If three speedtest sites say I am above the 500mb/s downloads, then why does it take so much longer to transfer those files?

I am also aware of how TCP/IP works, messaging back and forth in between data packets, CRC events and so on- but even adding them into the mix doesnt show the time difference. Its like dark matter. we know its there but we just cant see it.

So what exactly is the truth about broadband speeds? What is happening that reduces a true gigabit internet speed down to kilobytes?

Please, be as scientific and tech save as you possibly can because every response Ive gotten has been like I was asking a politician- lots of words but no answer..

Thanks!
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Philip
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Post by Philip »

Most data transfer speeds are calculated in Bits per second, not Bytes. So, 1 Gigabit per second is ~100 Megabytes/second, about 10 times difference. we have a calculator that helps with the conversions that may help understand it a bit better here: https://www.speedguide.net/conversion.php

What is advertised is always the maximum possible speed, real life can be much slower as you've noticed.
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YeOldeStonecat
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Post by YeOldeStonecat »

Sawtooth wrote:
I know that x + y = c. If you have DSL then their claim of say 100 mb/s = 50 upload and 50 download, and you are really only going to see 25 either way on the best hour of the day.
For my entire career in IT (also going to the very early dial up days)...internet is advertised in up/down speeds. We work with many..many different ISPs all the time all over the country. I've never seen an ISP advertise a connection where they list the speed as a sum of both download and upload. (your example has X + Y = C). ISPs quote speeds as "up to X amount down" or more often "X down, X up". So it may be a 100 meg down, 20 meg up. or 300 megs down, 50 megs up. Or it may be symmetrical, such as if you have an enterprise grade fiber connection...like 100 megs down 100 megs up. And we typically see at least 85%-90% of that value be true.
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Norm
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Post by Norm »

I believe some of your confusion is due to methods of measure. ISP's use terms in bits and Windows uses terms in bytes. There are 8 bits in a byte.

1 Gigabit = 1024 Megabits = 128 Megabytes (Your MAX Download speed would be 128 Megabytes/sec)

Gb = Gigabits
GB = GigaBytes
Mb = Megabits
MB = MegaBytes

Your questions are riddled with mismatching measurements. Speed tests are usually in Megabits.

Quote "So, lets say I am actually transferring data at 500mb/s. I want to transfer 5 gb of data. these numbers would suggest that my file transfer would only take 10 seconds. but it actually takes 15+ minute"

This should read "So, lets say I am actually transferring data at 500Mb/s. I want to transfer 5 GB of data. these numbers would suggest that my file transfer would only take 10 seconds. but it actually takes 15+ minute"

Makes a BIG difference (actually 8 x, since there are 8 bits to every byte.)
So, at a rate of 500Megabits/sec (which = 62.5 Megabytes/sec) a download of 5 Gigabytes of data would take 81.92 seconds. That's just over one minute.

Obviously your math was off.
Also, your speeds are far lower than they should be. Your speeds are close to mine for a 5 GB transfer, and I only have a 30Mb connection.

Do you EVER get to transfer at, or close to, your paid for speeds?

There are lots of other reasons for slow speeds. Busy servers, routers, VPN's, (your own computer and running software), throttling by servers etc.

Post your PC specs (including amount of ram) I'm curious about something.

If you never reach close to your paid for speeds, then there is something wrong.
The two guys posting above my post are about the most knowledgeable people around when it comes to Networks. I'm sure they'll figure it out.
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Post by Philip »

Hi Norm! :)
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Post by Norm »

Hi Philip, and hello to you too YeOldeStonecat good to see both of you still sharing your knowledge.

I hope I got it right, I'm a little rusty.

I have a little question (lol @ little question) It is related though.

What would actually happen on a PC with about 4 GB of ram, and an older HD, with a 1Gb connection trying to download a 5GB ISO file where max speed is attainable on the connection?

Since the old HD can't write at 128MB/sec, and there isn't enough ram for the entire file, what would happen?

Details please!!

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Post by Steeve49 »

Personally I live in France and I have 22.7Mbps ATM or 19.7Mbps IP in download and 1.2Mbps ATM or 1Mbps IP in upload in ADSL2+ with my ISP Free and excellent quality and stability of the connection with a SNR of 5db in down.
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Philip
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Post by Philip »

Norm wrote:Hi Philip, and hello to you too YeOldeStonecat good to see both of you still sharing your knowledge.

I hope I got it right, I'm a little rusty.

I have a little question (lol @ little question) It is related though.

What would actually happen on a PC with about 4 GB of ram, and an older HD, with a 1Gb connection trying to download a 5GB ISO file where max speed is attainable on the connection?

Since the old HD can't write at 128MB/sec, and there isn't enough ram for the entire file, what would happen?

Details please!!

Damn, I can't remember the syntax for that big green grin I used to use.
The TCP Receive Window buffer will fill up on your end, and it will effectively slow down the transfer speed until your hardware can keep up with writing the info to the HDD. It will not use up all your RAM, as the NICs limit memory use per connection (likely up to the TCP Window buffer).
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Post by Norm »

Philip wrote:The TCP Receive Window buffer will fill up on your end, and it will effectively slow down the transfer speed until your hardware can keep up with writing the info to the HDD. It will not use up all your RAM, as the NICs limit memory use per connection (likely up to the TCP Window buffer).
Thanks Philip, I wasn't sure what would happen, but I thought this MAY be the reason for the slow speeds of the original poster.

Now, would 16GB of ram help, or is the data going right to the HD in the form of a temp file, or would the ram hold the file while the HD catches up?
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Post by Philip »

Norm wrote:Thanks Philip, I wasn't sure what would happen, but I thought this MAY be the reason for the slow speeds of the original poster.

Now, would 16GB of ram help, or is the data going right to the HD in the form of a temp file, or would the ram hold the file while the HD catches up?
The connection will not fill the 16GB at all, it will only use a couple of Megabytes for a buffer, then it will slow down the transfer to the HDD speed, leaving the rest of the RAM unused. If the connection to the server is multi-threaded it may use up a bit more RAM, but it will still be a fraction of a Gigabyte.
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Post by Philip »

Sheldon47 wrote:I'm no expert but what I personally notice is the "business" internet connections are way faster that "home" internet connection despite the home connection speed is higher than business connection speed. There might be a difference in their settings.
You are right, as business internet connections are oversubscribed less than residential internet, as it is expected that they are used by multiple people at once, i.e. much higher resource utilization. Some connections can even be dedicated, but the cost increases substantially as well.
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