# Computer Speed?



## backwoods (Sep 12, 2004)

:huh:What is a "reasonable" computer speed and how is it measured?

What would .768 speed mean?


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## backwoodsman7 (Mar 22, 2007)

backwoods said:


> What would .768 speed mean?


.768 _what_? Numbers are meaningless without units. Where did the .768 come from?


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## Shoden (Dec 19, 2012)

By itself, .768 doesn't mean much.

However, the first computer related measurement that comes to mind with the number 768 is 768kb (kb is kilobits, i.e., 1000 bits, so 768kb is 768,000 bits), which is a measurement of your broadband internet connection speed. It's actually more accurate to state kb/s (kilobits per second) but most people leave off the /s part when talking about internet connections. It could either be the download speed for a low end DSL connection, or the upload speed for higher end connection.

For example, if it was a low end DSL service, you might have 768kb down, and 128kb up. With a higher end DSL service, you could have 3Mb down (approx 3000kb) and 768k up.

To see how those speeds compare to other internet connections:

Connection Type | Download Speed | Speed in bits/second *
dial up modem | up to 56kb | 56,000
low end dsl | 768kb | 768,000
high end dsl | 3Mb | 3,000,000
low end cable | 10Mb | 10,000,000
high end cable | 100Mb | 100,000,000
Google fiber | 1Gb | 1,000,000,000

* I rounded the speed in bits per second to keep things simple

The internet connection speed determines how quickly you can download files and view web pages on the internet.

The second number that comes to mind is computer memory, in which case it would most likely be 768MB, which is megabytes, or 768 million bytes. However, on a REALLY (late 80s, very early 90s) old computer, it could possibly be only 768KB, or 768,000 bytes. Even with 768MB, that would indicat a fairly old computer dating from the late 90s to early 2000s. Most computers now have around 4GB, or 4,000MB. 

The computer memory basically determines how much stuff your computer can do at once without slowing down.

The next number would be the processor speed. With a 768 number, that's most likely 768Mhz. Mhz is megahertz, which means a million cycles/operations per second, so at 768Mhz, that would be 768,000,000 cycles per second. An example of a 768Mhz would be an iMac G4, as well as some of the older Pentium II and III processors. Modern processors typically operate in the 2-4Ghz range, so 2,000-4,000Mhz. However, modern processors have another advantage other than raw speed. They also have multiple cores (anywhere from 2 to 8, and that number is increasing), so a new 4Ghz processor isn't just 5 times as fast as on older 768Mhz processor, it could be 10-40 times faster.

The processor speed basically determines how quickly a computer can do something.

It's also possible that the 768 could be referring to the hard drive size, which with that number would most likely be 768MB, which is megabytes, just like with the computer memory. However, a hard drive is used to store your programs and other files, and is MUCH slower than computer memory, even if it's the same size. Edited to add: Modern hard drives typically range from 500GB to 2TB (500,000,000,000 bytes to 2,000,000,000,000 bytes, which is considerably larger than the 768,000,000 byes of a 768MB drive)

I know my mom gets confused on this all the time, mixing up memory and storage, so I've explained it to her like this: Your hard drive storage is like file cabinets or bookshelves, it's where you keep stuff when you're not using it. Your computer memory is like your desk top (not to be confused with your computer desktop). When you've pulled stuff out of the file cabinets and off of the bookshelf, you spread it out on the desk while you're working with it. If you have a small desk, you can only have a little bit out at a time without having to shuffle stuff around and restack things, and you might have to get up to put stuff back in the file cabinet or on the bookshelf. With a bigger desk, you can spread stuff out and see more stuff at once and make fewer trips to the file cabinet/bookshelf.

So, to sum up, 768 could be:

768Mb/s - internet download speed, how quickly you it download files and web pages
768MB - your computer memory, or how much stuff it can work on at once
768Mhz - your computer processor speed, or how quickly it can do stuff
768MB - your computer hard drive, or how much stuff it can store.

It's most likely the 768Mhz option, or your processor speed. Depending on what you do with your computer, that could still be reasonable. If you like to edit HD video, play the newest computer games at the highest video quality, do CGI animation, or other high demand applications, that probably isn't reasonable. However, if all you do is write documents, keep a spreadsheet or personal finances program, view webpages, send email, and watch Youtube videos, it may be reasonable.


And at the risk of confusing things, you may have noticed the Mb (megabits) vs MB (megabytes). A bit is a single 1 or 0 used in binary code, while a byte is 8 bits, and a single byte can have 256 different values. It's those 256 values that are used to represent letters, numbers, and special characters. So each letter, number, punctuation mark, etc, are 1 byte each, or 8 bits. So going back to the internet download speeds, lets look at the 56Kb/s speed. That's 56,000 bits per second. Dividing by 8 gives us the bytes per second, or characters (letters/numbers/etc) per second, which is 7000 characters per second. And that's still keeping things fairly simple, since there are different encoding schemes (i.e, using two bytes per character) and control characters, error correcting, IP packaging, etc, that use up a portion of those 7000 characters, so it means you can't actually download a 7000 letter document in 1 second at 56Kb/s.


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## backwoodsman7 (Mar 22, 2007)

Shoden said:


> 768Mb/s - internet download speed, how quickly you it download files and web pages
> 768MB - your computer memory, or how much stuff it can work on at once
> 768Mhz - your computer processor speed, or how quickly it can do stuff
> 768MB - your computer hard drive, or how much stuff it can store.


Could be #1 or #2. I don't think anyone ever made a 768MHz CPU or a 768MB hard drive, but I could be wrong, so #3 and #4 are very unlikely. In any case, there's not really anything more to say until we hear more from the original poster.


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## unregistered5595 (Mar 3, 2003)

Shoden, that was a very nice post. Comprehensive and well explained. 

I was just talking with a good friend and she asked me to help her understand what kind of internet service would best fit her needs. I hope you don't mind, I'm going to copy and paste your post in an email to her to begin the conversation on what speed of internet she should buy--if you don't mind.

It is so well organized, thank you!


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## backwoods (Sep 12, 2004)

Feather In The Breeze said:


> Shoden, that was a very nice post. Comprehensive and well explained.
> 
> I was just talking with a good friend and she asked me to help her understand what kind of internet service would best fit her needs. I hope you don't mind, I'm going to copy and paste your post in an email to her to begin the conversation on what speed of internet she should buy--if you don't mind.
> 
> ...


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## notthereyet (Nov 17, 2011)

My first thought was that this was in reference to internet speed. 768k is the about as low as you can get and still call it broadband.

BUT! Consider Comcast Cable. I have a 25Mbit/s connection (about 30x faster than your 768k). The downside, is that Comcast limits subscribers to 250GB of total transfer per month. Doing the math: 250GB is 8.3GB per day, 347MB per hour, 5MB per minute, .096MB per second, which comes out to 771kb/s of actual, usable broadband.

Comcast sucks.


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## backwoodsman7 (Mar 22, 2007)

backwoods said:


> It was internet service I was trying to figure out also.


Then the 0.768 would be Mbps (or Mb/s, or megabits), or more commonly written as 768 Kbps. To put that in perspective and give a meaningful frame of reference: I run a small wireless internet system, and I find that most typical users are happy with 1 megabit, which is fast enough for Youtube, Netflix, and the like. Once you get to 1 megabit, most users will never notice anything faster, so for most people I wouldn't recommend paying extra for more speed than that, unless multiple users want to use Youtube etc. at the same time. Even then, I'd say start with the lower (cheaper) speed, and upgrade only if you find it insufficient.

The thing that most people associate with "fast" or "slow" on an internet connection, is really the latency between clicking a link and a page being loaded, and has little to do with the actual data rate. To most users, a 256Kbps connection that works as it should will seem faster than a 2Mbps satellite connection that takes 5 seconds for a page to start loading.


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