Help me understand something about internet upload speeds

[TheForce]

I'm beginning to do more and more large file uploads to my hosted server. I have good capacity for storage and bandwidth with my basic contract.
My ISP is Comcast and I have a commercial account that is provisioned for 30Mbs down and 5Mbs up. If I use speedtest.net I can verify this on most servers in their list.

However- when I upload my files I get varying results all much slower.
Video editing computer- i7-950, ethernet wired connection- using cpanel to connect for upload I am averaging 300 KB/s
Office Computer - i7-950 ethernet wired connection using wsftp for upload I average 71 KB/s
Office Computer - i7-950 ethernet wired connection using cpanel fpr upload the speed is 132 KB/s

Why are my actual upload numbers so much slower than my tested speedtest.net results? There must be something in the numbers on my uploads I'm missing. Even similar computers connected the same way the numbers vary greatly.

Is it the lower case b vs upper case B difference? In other words, if I equate the 5Mbs to KB/s it would be 5000 / 8 = 625 Right?

In fact my fastest upload data point is 300 KB/s but this is average over the full large 1 Gb file. When I initiate the upload the initial speed is indeed 619 KB/s but after about 5-7 minutes it slowly falls off to 300 as stated above.

If the above thinking is correct, why the fall off and also why the huge difference in methods using the same hardware but different clients?


TIA

 

[StevenD]

Your above thinking is correct. The max you will see is 640KB/s. That being said, I'm not sure where the slowdown is.

 

[mike123abc]

Just like the downlink, the uplink on cable modems is shared with others in the neighborhood, it could be you live in a torrent happy area...

 

[berck]

If you want to get a more accurate measure of your true download and upload speeds, go to dslreports.com. Their speed test actually test the upload / download speeds with file transfers. The faster the link, the bigger the files get. It will report the true average achieved over all the file transfers. Although my Comcast link can down load upto 25Mbps according to speedtest.net, the actual average tends to be closer to 12Mbps from dslreports.com.

I always view speedtest.net as more of instantaneous speed.

 

[ShadowEKU]

could also be a bottleneck at the download of the hosted server (your upload being their download)

there are a few other copy tools out there to use over ftp, but mainly FTP has a ton of overhead.

 

[TheForce]

Thanks for verifying my thinking.

Maybe I need to inquire at Comcast and ask if they throttle back my upload speed after a few minutes of sustained transfer.

As far as the different clients, I suppose I should just attribute the difference to different code efficiency. Using a Browser and cpanel is definitely faster over the entire large transfer.

 

[Neutron]

You also need to take into account overhead. You will never truly see 5Mbit/sec on your upload.

The reason it looks like its faster in the beginning of your transfer is just due to how the operating system calculates the speed of the transfer.

 

[rvvaquero]

Bandwidth is not just limited at your ISP. Your target server also imposes caps. For example, Youtube is very much interested in getting their product into your computer, so download speeds are at the top of their capability. However, they realize that you will want to post your video bad enough to have the patience to put up with limited upload speeds. It has taken me several hours to upload a 3/4 gb video to Youtube before, yet I can download and view that same video in three minutes. Just saying.

 

[TheForce]

I'm not talking about YT here. And, I know the limits of my business account with Comcast which is different on uploads vs. downloads. I thought I said this was when uploading a large file to my own server that is hosted by a service. Same as satelliteguys does. It owns it's own server but it is hosted at a service, not at Scott's house. According to my service the limits it places in receiving an inbound file are not restricted below 100Mb/s. My upload ISP ( Comcast) does restrict to 5 Mb/s. It appears that my upload starts out at rated speed but falls off after a sustained upload lasting longer than 5 minutes. When I made my tests, I made sure my upload was clean and no other devices were hitting the network at the same time. I got real busy today and didn't get a chance to contact my AE at Comcast but I did learn the limits at my server host and it doesn't appear they are the cause.

I just recalled that there was some discussion at Comcast a couple years ago about burst speed and sustained speed limits. That was back when the upload was really low, like 350kb/s They would provision the account for 350 but it would fall off to about 100 kb/s. I thought they stopped doing that but maybe it is still a practice. The contract rated speed is burst. But, back then download was also burst and then dropped off. Today, I can download a large file off my server at 28950 Mbs average for hours on end. Do you all know why there is this bust vs sustained difference?

I suppose what I am trying to determine here is if the problem is on my end, my ISP, or my Host. I think I can eliminate my host. I would not be surprised if Comcast says, "you need a new Cable Modem" as the one I have now is about 4 years old.

 

[mike123abc]

I would strongly suspect it is Comcast. Probably some fair access policy that throttles down large uploads.

 

[Hall]

I'd ask here, DSLReports, Comcast HSI forum

 

[rockymtnhigh]

Hmm...

got an email from Comcrap saying they have increased my upload speeds from 5MB to 15MB on my Extreme 50 service.

Did a quick speed test on my wireless laptop:



Didn't get 15, but was pleased all in all - considering this was a wi-fi connection, and not wired.

 

[Neutron]

Suddenlink changed ours earlier this month from 10 to 15Mbps and my speed tests have been all over the place from 7 up to 30 at times. Very odd.... My ping time is usually 70-100

 

[Hall]

I thought I'd read that many cable providers use "boost" tools that make speed tests look really good, but aren't necessarily always sustained speeds. It appears that sometimes they do sustain these higher rates, so I imagine it's dynamic and based on capacity at the time the download(s) are taking place.

 

[rockymtnhigh]

That particular test had a ping of 20. No complaints - and to be honest, my service is generally excellent. I stream HD over iTunes and Netflix all the time, and never have a hiccup. Now if they would turn the Extreme 50 into Extreme 100 for the same price, then I'd be happy

And thinking about it with uploads, last week I redid my dropbox configurations which resulted in a lot of files re-downloading, and being uploaded; and it went very quickly - more so at home then when the machine was on the supposedly far faster campus network.

 

[Neutron]

I can upgrade to the 30Mbps/2Mbps speed but to me it's just not worth an extra $30 a month, or even $20 a month if I decide to buy my own cable modem. Either option will require that we upgrade to a DOCSIS 3.0 modem as they have me using an older Motorolla SB DOCSIS 2.0 modem now.

 

[rockymtnhigh]

I can upgrade to the 30Mbps/2Mbps speed but to me it's just not worth an extra $30 a month, or even $20 a month if I decide to buy my own cable modem. Either option will require that we upgrade to a DOCSIS 3.0 modem as they have me using an older Motorolla SB DOCSIS 2.0 modem now.

Upgrading to a DOCSIS 3 modem was the best thing I ever did. You are crazy not do it even where you are now. Before I had 50, and just had 20MB service, the upgrade to DOCSIS 3 made a huge difference.

And why are you leasing a modem? They cost less than $100. The Motorola SB6160 (I think that is the model - scary that I should know that) works great, and is rock solid.

 

[Neutron]

Upgrading to a DOCSIS 3 modem was the best thing I ever did. You are crazy not do it even where you are now. Before I had 50, and just had 20MB service, the upgrade to DOCSIS 3 made a huge difference.

And why are you leasing a modem? They cost less than $100. The Motorola SB6160 (I think that is the model - scary that I should know that) works great, and is rock solid.

Haven't had the chance to get one yet. Money has still be tight for us.

 

[Hall]

I'm not sure that all cablecos allow -- or at least make it attractive -- to use your own cable modem. I remember seeing cable modems in stores, i.e. Best Buy, Circuit City, Wal-Mart, etc years ago but they're not anymore (locally). Why ? IMO, because they didn't sell. Either people weren't interested or Time Warner (the cableco here) frowned upon it (I can hear the "we don't support the modem you bought on your own" with our service, i.e. "you're on your own !").

 

[rockymtnhigh]

Comcast has never had a problem with it - thankfully.