Helping people with computers... one answer at a time.

I've set up an ftp server. My ISP is giving me an ADSL connection with an speed they say is 768k for uploads and 8meg down. And yet I'm seeing my uploads are around 85k and 90k.

I need faster uploads. Can I change something about my system to make that happen?

There's one big potential point of confusion here, so let's take this opportunity to review upload and download speeds, what they really mean, and what you can do to maximize them.

The person asking the question had also gone to some of the on-line speed testing sites, such as that at Broadband Reports. The numbers being show there more-or-less matched the figures that his ISP was providing.

That's actually good news. And, to be honest, I'm quite jealous. 768k up / 8meg down looks wonderful to me - because of telephone company limitations (and no cable in my area) I'm limited to 128k up and 768k down. Once upon a time that was blazingly fast. Now, not so much. Did I mention I'm jealous?

But just what do those numbers mean?

First, realize that they're measurements in bits per second or bps. That means on my DSL connection, I can upload at a maximum speed of 128k, or 131,072 (128 x 1,024) bps. Similarly, I can download at a maximum of 785,432 (768 x 1,024) bps. My faster questioner can upload at 785,432 bps and download at a whopping 8,388,608 (8 x 1,024 x 1,024) bps.

But we measure downloads and file sizes in bytes not bits. So a more meaningful number might be the download speed in Bytes per second (Bps - notice that the "B" is capitalized? Subtle.) With 8 bits to a byte, a speed of 768k bits per second works out to ... 98,304 Bytes per second, or 96KBps.

So when you say that you're seeing uploads at around "85k and 90k" it leads me to wonder if you're measuring your uploads in Bytes per second, and comparing to the line speed expressed in bits per second. If that's the case, then the numbers you're seeing are quite reasonable.

Why aren't they actually at the 96KBps I calculated your line speed to be in Bytes per second?

In a word: overhead. If you're measuring based on file size, then the communications protocols involved in transferring that file break it up into "chunks", adding a little bit of overhead data to each chunk to create a packet that can then be properly reassembled into the original file. There are also overhead delays involved in most communications protocols - the time it takes to start sending each packet and the time it takes to verify and acknowledge back that the packet was properly received.

"The bottom line here is that your connection to the internet is most likely your real bottleneck."

Because of that overhead, I typically just divide by 10 for a rough estimate of actual, effective transfer rate. My 768kbps DSL roughly downloads at around 76KBps, or 76k Bytes per second. Very roughly. But it's slightly easier math, then, to see about how long my next download will take.

And of course other network traffic can affect the effective speed as well. If you're downloading your email while you're uploading a file on the same internet connection, both operations will slow down some. If you're on cable, you're actually sharing your bandwidth with your neighbors - so if they're doing something internet-intensive, that could also impact your speeds.

The bottom line here is that your connection to the internet is most likely your real bottleneck. Barring other software on your machine that's 'clogging the line' trying to do something on the internet at the same time you are, you're at the mercy of the capacity of that line, and what your ISP can provide you.

Article C2635 - April 26, 2006 « »

Leo Leo A. Notenboom has been playing with computers since he was required to take a programming class in 1976. An 18 year career as a programmer at Microsoft soon followed. After "retiring" in 2001, Leo started Ask Leo! in 2003 as a place for answers to common computer and technical questions. More about Leo.

Not what you needed?

Greg Bulmash
April 28, 2006 10:57 AM

Have to agree that he may be looking at KBps instead of Kbps. When I'm using WinSCP to upload it reports in bytes per second, not bits. But, as a caveat, in an upload/download, it always takes two to tango.

If you're uploading to a heavily used server, it may well be that enough of its available incoming bandwidth is being parceled out to other uploaders and server functionss that it only has 85-90 kilobits per second available for receiving your upload. That would explain your observed speeds.

I have an 8/768 line through Comcast, but my cable doesn't enter the house anywhere near my home office, so I use BPL (Broadband over Power Line) bridges to connect the router in my home office to the cable modem in another room.

That gives me an effective speed of around 4400/695, which is around what I was getting with a 6/768 DSL line going straight into the office that cost me 2x as much.

I don't mention my speeds to help you, though. It's just to rub it in with Leo. Comparing his house to mine is like comparing a Bentley to a Honda. So, though I have "estate envy", I have at least this one thing to feel smug about.

April 29, 2006 7:03 AM

A surprise to me was finding out that as the available bandwidth goes up older routers may actually be a limiting factor (at least for download). Tom's Hardware recently put up a chart showing upload and download capabilities of routers over time and some of the older ones won't keep up with 8mbs down. A friend of mine recently confirmed this on his connection by after swapping out a fairly old LinkSys.



April 30, 2006 9:22 PM

How much wattage does a laptop require, I have a HP and a Dell and I want to use them in my truck

April 30, 2006 10:34 PM

it varies. Take a look at the power adapter and it should have a wattage rating on it.

pc tech
July 8, 2006 7:24 PM

You are getting right at your true speed... You are looking at the wrong term..

90KB X 8 = 720Kb/s upload...

DONT get Kb and KB mixed up.. many people do.

90 times 8 is 720

Robert Bozeman
March 15, 2009 12:24 AM

I have AT&T Uverse 18max, 18meg download speeds and about 1.5 upload. My PC with wireless modem does a speed test about 8500 download & 1500 upload from St Louis to Chicago, BUT my cheap $600 HP laptop with built in wireless WIFI modem gets 17,500 download speeds and 1500 upload in the same room. What gives? They both have Norton Internet Security, and even if I turn it all off on my PC, nothing changes. I made sure the Windows firewall is turned off, ran a defrag, scandisk, full virus scan, see no other processes running etc., and it still won't budge above 8500 download. So why does my cheap ass laptop get faster download speeds? I have 2meg of RAM in my PC, more than the 512k in my laptop. Do I have to delete pics, music & movies for it to get faster? I don't see what difference that would make since none of them have anyhing to do with active programs. Please give me a suggestion on what to do. Thanks.

Robert Bozeman
April 15, 2009 9:56 PM

Figured it out. Had to adjust my packet size. Now getting what I'm paying fo

Comments on this entry are closed.

If you have a question, start by using the search box up at the top of the page - there's a very good chance that your question has already been answered on Ask Leo!.

If you don't find your answer, head out to to ask your question.