Disk drives are wierd. There is capacity and formatted capacity and marketing.
1000 units per K is better for marketing
1024 units per K isn't.
Memory is sold as 1024 units/K as far as I know.
Disk drives have raw capacity.
They have formatted capacity.
They have hidden bad block tables.
They have calibraion data.
They have partitions.
We need a number to buy a drive. That's going to be raw capacity.
We need a number to tell us what will fit on a used drive. What used to be called "Free blocks" or 512 block sectors way back when. Then things started to get wierd.
1 character files took up Sixteen - 512K blocks etc.
It's not an exact science. I once did a presentation (A few hundred people) on a the directory structure that was used on a small minicomputer. Back then I understood it. The OS was limited in storage and the largest integer. Growth in capacity was not built in. The same thing happened with DOS/Windows.
Kiss, don't even mention modern solid state disk drives where there's so much going on inbetween the actual storage element and the system controller itself as to blur the line between processing and storage. Nowdays everything has a processor more complicated than the ultimate state of the art machines did 10 years ago.
I think of the simplest form I can right now which is a flash memorty card, aside from the actual flash memory every SD card on earth has both a standard SPI interface, a high speed proprietary SD interface and virtually anything larger than the micro format also contains a USB slave controller for a controller-less PC interface
Last edited by Sceadwian; 22nd January 2012 at 12:22 AM.
Hi again, when you speedtest.net your internet speed, you see three different stats showing up. Download Speed, Upload speed and Ping. Whats this ping? How is it important?
Last edited by Electroenthusiast; 1st July 2012 at 04:31 AM.
Q3: How can 525 lines NTSC standard display have a quality of 720pixel / half HD?
It depends what they are showing as there are a number of ways of measuring it. It represents the "latency" or time delay between packets leaving the test machine and arriving at yours.
It is important because you could have a very high bandwidth link that is actually quite "slow". Consider a 1 gigabyte per second link between here and the moon. It might be capable of high data rates but it could still take a few minutes for data to arrive at the other end.
An analogy would be a very wide, very long water pipe. Lots of data can go IN one end every second, lots of data can come OUT the other end every second. But the total time for data to traverse from IN to OUT is not instantaneous.
Private messages are for personal communication, please do not use them to ask for help.
Just a minor technicality but ping time is not one way trip measure, it's the time it takes to get to a destination and back, it's called a ping like a sonar echo location ping.
Bad ping times can affect some protocols that rely on a large number of ack/nack requests for transfer verification, as it spends more time waiting for the ACK/NACK's that it does actually transferring data. It will affect general web browsing if it get up past around 100ms or so, 200ms or more can drastically affect how fast your connection 'feels' regardless of how high the transfer rate is, but you shouldn't see pings that high unless you use satellite Internet because the up-stream for satellite is a phone line.
Ping time is hyper critical for some online games like first person shooters and most real time multiplayer games.
Using the cmd prompt and using "ping <router address> -t -n 8192 "
CNTRL+C - stops this test
"ping 127.0.0.1" is also known as "localhost". It can tell you if your PC's TCP/IP stack is working.
Some, because of abuse, disable ping from outside of the network. My ISP disables windows traceroute, but if I go though some hoops and use a different packet, it will work. The ISP doesn't want you to know your public IP address. www.whatismyip.com will easily tell it to you. It changes at some rate depending on your ISP. If you rest your modem you will likely get another.
If you have large latencies, it can help you diagnose wiring issues. I still haven't figured out whether your public IP address and your Private IP address access the same wire segment or whether it's different if you access from outside the connection. I used to be able to do this, but I don't have the account anymore. I could log onto a Unix system and then ping back to me.
I just don't understand the router concept especially in my case. The router's config address is 192.168.0.1, but the router's address is 10.0.1.1 and the <public address> is something different.
Really? I've not found this to be the case myself. Your local IP address is always your public IP address around here at least on the cable or DSL services, although with DHCP leasing it can change (I don't think mine has since I got it) I guess it depends on the ISP.Originally Posted by KISS
It sounds like your ISP does some really strange routing, you don't technically have Internet access, you have access to a NAT service that does, where as the services around here provide true internet access, meaning the IP I have is a TRUE IP that routes directly to my cable modem. I'm NAT'd from there though as I have a house router, but with UPNP routers nowdays and software that knows how to use it you'll never even notice.
See, tracert disabled
Tracing route to www.l.google.com [188.8.131.52]
over a maximum of 30 hops:
1 * * * Request timed out.
2 * * * Request timed out.
3 * * * Request timed out.
Yep, I have access to a NAT service that does, the address the the ISP assigns is public.
See: http://joesbitbucket.blogspot.com/20...s-tracert.html about tracert varients.
When I had Cygwin installed, I could get that version of tracert to work with checked options. It is annoying.
I should have said that my DSL modem has the config address of 192.168.1.1, BUT my router has the address of 10.0.1.1. The router does not have an HTTP interface. The DSL modem does. It's obvios that the DSL MODEM config address (http) is not on my network. The DSL modem is in BRIDGE Mode. I don;t understand how the mode actually works.
In order to config the modem, I have to connect via an Ethernet cable and put my laptop on the 192.168.0.x network.
I'm not sure if i could change the config address of the DSL modem to say 10.0.1.127 and be able to access it.
I'm being different:
I have a DSL modem operating in BRIDGE mode
I have a router capable of dial-up and DSL wireless internet. Wireless is broken and I haven't pulled the card. It's card based and 802.11b.
I have an Access point providing wireless services.
and I have a b/g Repeater.
Wierd things happen. One of them is if I start to connect near the repeater and then start walking with the laptop so it's in range of the base, it won;t connect automatically.
Very, very rarely wireless networking will totally quit and a reboot is the only fix (WIN 7). It used to happen on an XP machine and a Net stop Wireless zero Configuration and re-starting would always fix it. I can't find a fix in win 7. Fortunately it's very very rare. 2-3 times a year.
My version of Windows suffered from the bug that you could have a red X in the wireless ICON in the system try, but be connected wireless to the Internet. I fixed that with a group policy. Wireless connectivity from wakeup is typically slow, but it will connect unless I walk with the laptop during the connection process.
I know I can access devices from outside the home, or used to be able to, because I had my Slingbox and router configured properly with port forwarding.
Just not sure what the router does with a 192.168.1.x packet generated on the 10.0.1.x side. It doesn't appear to pass it through the router port. It is supposed to be non-routeable, but what device enforces that?
Not sure how and if adding static routes to Windows will make this work.
If I ping 192.168.0.0 and arp -a, it nothing is in the arp table
Last edited by KeepItSimpleStupid; 1st July 2012 at 11:04 PM.
@kiss, sceadwian, edeca
there arises two ques,
from what i understand, ping is the time required to make a 1 to-and-fro cycle. So does it depend on the distance between the server and my PC?
Since, all the signals travel in speeds of light, the highest possible ping is 50ms . But, i've heard a numbers more than that.
sceadwian, i don't understand this " ack/nack's ", neither google search helped me. Maybe, i need to search for a book titled like "Internet Demystified".
Q3: How can 525 lines NTSC standard display have a quality of 720pixel / half HD?
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