| Author |
Message |
Bruce Gillis
Guest
|
 Posted:
Thu Nov 18, 2004 12:07 am Post subject:
Confirm: Which is Faster - External Versus Internal Modem? |
|
|
Hi. I have been pondering my choices for a quality dial-up modem for
my PC. I will be going with the best brand for modems (US Robotics)
but I have come up to a kind of mental stumbling block. As I was
going around the local shops to find the market value of a modem, a
Radio Shack jobber told me that an external modem would hook up with
the Internet a *lot* faster than an internal modem of the same speed
rating and specs (56K; V92).
I was surprised to hear this, but I wasn't convinced so I wanted to
confirm this at another computer store (Computer Resource). There,
the guy told me someting to this effect, "An external modem will be
slower than an internal one and will be three times the cost." Now
everything is so clear!!
Now, I am more confused than ever. I want the fastest 56K modem
around but I am uncertain whether to go with an internal or external
modem. Can someone knowledgeable about modems clarify this for me?
Much appreciated,
Bruce |
|
| Back to top |
|
 |
Guest
|
|
| Back to top |
|
|
Robert Nichols
Guest
|
| Posted:
Thu Nov 18, 2004 4:52 pm Post subject:
Re: Confirm: Which is Faster - External Versus Internal Mod |
|
|
In article <2c942c97.0411171107.27fe2a57@posting.google.com>,
Bruce Gillis <brucekg78@yahoo.com> wrote:
:
:Now, I am more confused than ever. I want the fastest 56K modem
:around but I am uncertain whether to go with an internal or external
:modem. Can someone knowledgeable about modems clarify this for me?
You think you're confused now?? You ain't seen the half of it yet!
For starters, you have to define what you mean by "fastest". Do
you want:
a) maximum throughput for bulk data transfers,
or b) lowest latency (a consideration for online gaming)?
To a certain extent, these are contrary requirements. The blocking
and data compression that speed up bulk transfers also increase
latency.
If you are looking for maximum bulk data throughput, an external modem
can send and receive no faster than the speed of the serial port to
which it is connected (perhaps 115200 bps), whereas an internal modem
does not have that limitation. However, in order to get much more than
the link rate of 51 Kb/s the data would have to be highly compressible,
and that would be quite unusual unless you are routinely downloading
huge, uncompressed text files.
An internal modem potentially has lower latency than an external modem
because the data does not have to go through a parallel -> serial ->
parallel conversion. However, a controllerless internal modem (as most
are) steals CPU cycles to do its job. Unless you've got a lot of excess
CPU capacity, that's likely to slow your game down and negate the
latency improvement.
In practice, unless you've got a fairly slow CPU (which would mean that
a controllerless internal modem is a really bad idea) the ability of a
modem to deal with the imperfections of your particular phone line is
going to far outweigh any speed differences due to internal vs.
external. Sorry, can't help you on that one.
BTW, legacy serial ports seem to be disappearing like 1.44MB floppy
drives on modern systems. Last time I looked, most motherboards still
had a serial port, but I wouldn't want to predict how long that will
last.
--
Bob Nichols AT comcast.net I am "rnichols42" |
|
| Back to top |
|
|
MasterBlaster
Guest
|
| Posted:
Thu Nov 18, 2004 5:50 pm Post subject:
Re: Confirm: Which is Faster - External Versus Internal Mod |
|
|
"Bruce Gillis" wrote
| Quote: | Radio Shack jobber told me that an external modem would hook up with
the Internet a *lot* faster than an internal modem of the same speed
rating and specs (56K; V92).
|
Sounds like the salesdroid who said I'd never get a good speed with an ISA
internal modem. This was back when I still had my 486 and was just calling
local BBS's (Bulletin Boards) I was looking for something a bit faster than the
14.4k I had at the time.. He actually refused to sell me one, so I went to another
store and got the same modem for $5 less. I was happily hooked up at 31k for a
year, until I got a Pentium and the Internet.
Now it connects at 50,666 9 times out of 10. That isn't a good speed???
I think the RS droid wanted to sell you an external because they cost more.
They're on commission, and Christmas is coming up.
| Quote: | I was surprised to hear this, but I wasn't convinced so I wanted to
confirm this at another computer store (Computer Resource). There,
the guy told me someting to this effect, "An external modem will be
slower than an internal one and will be three times the cost." Now
everything is so clear!!
|
The CR droid was basically saying the same thing as the RS droid, but you
must have been wearing shabbier clothes that day and he figured you'd
never spring for the higher-priced external.
Cost:
With a few exceptions, most newer internals will be Winmodems.
No brains onboard; Windows & the CPU have to do everything.
Also known as "controllerless" or "software" modems.
Externals & "hardware" internals have their brains onboard. $$$
Internals go inside (externals need a case). $$$
Internals plug into the motherboard (externals need a cable). $$$
Internals get power from the motherboard (externals need a power supply). $$$
Internals don't tell you what they're doing (externals have pretty lights). $$$
Internals won't hang up if the software says no (*click,* external's off).
Function:
About the only good thing about Winmodems is they're cheap, and can
be "upgraded" by installing new software. Externals & hardwares can be
too, by flashing them with new firmware, but only if the manufacturer feels
like writing it, or if a third party hacks up some better code.
Speaking of code, some manufacturers *may* have "better" code running
in their modems, which could potentially help with speed by reducing errors,
increasing compression, handling line noise better, etc. That may be what
RS droid was referring to.
| Quote: | Now, I am more confused than ever. I want the fastest 56K modem
around but I am uncertain whether to go with an internal or external
modem. Can someone knowledgeable about modems clarify this for me?
|
My old AOpen ISA internal (now in Mom's machine) usually connects at 50666.
My USR 33.6/28.8 v.everything external that I found in the dumpster and flashed
to 56k usually connects at 50666.
The USR internals I found in the same dumpster and flashed to 56k with the help
of a Russian programmer's site (even the modem that seemed completely dead
from a bad previous flash) usually connect at 50666.
These days, I think it's just personal preference.
Do you like neat, tidy and only one (phone) wire? Go with an internal.
Do you like flashing lights and easy swaps between machines? Grab an external.
Do you like cheap above all else? Winmodem it is.
Just my opinion, and like anything free, probably worth exactly what you paid for it. |
|
| Back to top |
|
|
Guest
|
| Posted:
Thu Nov 18, 2004 10:44 pm Post subject:
Re: Confirm: Which is Faster - External Versus Internal Mod |
|
|
On Thu, 18 Nov 2004 04:51:20 GMT, "GEO" Me@home.here wrote:
| Quote: | On 17 Nov 2004 11:07:12 -0800, brucekg78@yahoo.com (Bruce Gillis)
wrote:
Now, I am more confused than ever. I want the fastest 56K modem
around but I am uncertain whether to go with an internal or external
modem. Can someone knowledgeable about modems clarify this for me?
|
Well, it looks as if you might be better off with an internal modem:
"If your V.92/V.44 modem connects via a 'real' serial port you're in
trouble: most serial ports on PCs aren't able to handle real data
at these rates. The 16550 UART typically found for COM ports is
limited to 115.2kbps - and 20% of that rate isn't data - so, only
92,160bps of data can be achieved on a COM port set at 115.2kbps.
(This can also be a factor with V.42 compression which, as you can see
above, can also produce the potential for >115.2kbps transmission.)
Even a 230.4kbps COM port wouldn't accommodate the throughput I got
on my Softmodem's V.44 46.6kbps connect! Well-designed controllerless
and softmodems aren't only much less expensive than
hardware-controller modems, they can give better performance!"
http://modemsite.com/56k/v92v44v42.asp
HTH
Geo |
|
| Back to top |
|
|
TE Cheah
Guest
|
| Posted:
Fri Nov 19, 2004 11:26 pm Post subject:
Re: Confirm: Which is Faster - External Versus Internal Mod |
|
|
| an external modem
| can send and receive no faster than the speed of the serial port to
| which it is connected (perhaps 115200 bps)
This is relevant only to ISDN 2 B channel ( 128 kbps ) & above, not to a
v92 mdm.
For online Realvideo, the size of UART's buffer is relevant, to avoid
*serial overrun errors : my int mdm has 64 byte = end of *.
11-20-2004 01:09:27.37 - Smart Link 56K Voice Modem in use.
11-20-2004 01:09:27.37 - Modem type: Smart Link 56K Voice Modem
11-20-2004 01:09:27.37 - Modem inf path: OEM0.INF
11-20-2004 01:09:27.37 - Modem inf section: Modem1
11-20-2004 01:09:28.07 - 460800,N,8,1
11-20-2004 01:09:28.07 - 460800,N,8,1
11-20-2004 01:09:28.07 - Initializing modem.
11-20-2004 01:09:28.07 - Send: AT<cr>
11-20-2004 01:09:28.07 - Recv: AT<cr>
11-20-2004 01:09:28.07 - Recv: <cr><lf>OK<cr><lf>
11-20-2004 01:09:28.07 - Interpreted response: Ok
11-20-2004 01:09:28.07 - Send: AT &F E1 V1 &A3 &D2 &C1 S0=0 [ESM<cr>
11-20-2004 01:09:28.07 - Recv: AT &F E1 V1 &A3 &D2 &C1 S0=0 [ESM<cr>
11-20-2004 01:09:28.07 - Recv: <cr><lf>OK<cr><lf>
11-20-2004 01:09:28.07 - Interpreted response: Ok
11-20-2004 01:09:28.07 - Send: ATS7=60S19=0L3M1\N3%C3&H1N1X4<cr>
11-20-2004 01:09:28.07 - Recv: ATS7=60S19=0L3M1\N3%C3&H1N1X4<cr>
11-20-2004 01:09:28.07 - Recv: <cr><lf>OK<cr><lf>
11-20-2004 01:09:28.07 - Interpreted response: Ok
11-20-2004 01:09:28.07 - Dialing.
11-20-2004 01:09:28.07 - Send: ATDT;<cr>
11-20-2004 01:09:28.08 - Recv: ATDT;<cr>
11-20-2004 01:09:32.57 - Recv: <cr><lf>OK<cr><lf>
11-20-2004 01:09:32.57 - Interpreted response: Ok
11-20-2004 01:09:32.57 - Dialing.
11-20-2004 01:09:32.57 - Send: ATDT####<cr>
11-20-2004 01:09:32.57 - Recv: ATDT1515<cr>
11-20-2004 01:10:03.88 - Recv: <cr><lf>MODULATION: V.90
11-20-2004 01:10:03.88 - Interpreted response: Informative
11-20-2004 01:10:03.88 - Recv: <cr><lf>PROTOCOL: LAPM
11-20-2004 01:10:03.88 - Interpreted response: Informative
11-20-2004 01:10:03.88 - Recv: <cr><lf>COMPRESSION: V.44
11-20-2004 01:10:03.88 - Interpreted response: Informative
11-20-2004 01:10:03.88 - Recv: <cr><lf>CONNECT 45333<cr><lf>
11-20-2004 01:10:03.88 - Interpreted response: Connect
11-20-2004 01:10:03.88 - Connection established at 45333bps.
11-20-2004 01:10:03.88 - Error-control on.
11-20-2004 01:10:03.88 - Data compression on.
11-20-2004 01:21:36.97 - Hanging up the modem.
11-20-2004 01:21:36.97 - Hardware hangup by lowering DTR.
11-20-2004 01:21:37.47 - Recv: <cr><lf>NO CARRIER<cr><lf>
11-20-2004 01:21:37.47 - Interpreted response: No Carrier
11-20-2004 01:21:37.47 - Send: ATH<cr>
11-20-2004 01:21:37.98 - Recv: ATH<cr>
11-20-2004 01:21:37.98 - Recv: <cr><lf>OK<cr><lf>
11-20-2004 01:21:37.98 - Interpreted response: Ok
11-20-2004 01:21:37.98 - 460800,N,8,1
11-20-2004 01:21:38.99 - Session Statistics:
11-20-2004 01:21:38.99 - Reads : 2249618 bytes
11-20-2004 01:21:38.99 - Writes: 108550 bytes
11-20-2004 01:21:38.99 - Smart Link 56K Voice Modem closed.
16550 UART is obsolete, buffer is too small to avoid *.
05-27-2004 19:42:12.26 - 56kbps PnP External Fax Voice Modem in use.
05-27-2004 19:42:12.26 - Modem type: 56kbps PnP External Fax Voice Modem
05-27-2004 19:42:12.26 - Modem inf path: 56KMFG~1.INF
05-27-2004 19:42:12.26 - Modem inf section: Modem51
05-27-2004 19:42:12.48 - 115200,N,8,1
05-27-2004 19:42:12.48 - 115200,N,8,1
05-27-2004 19:42:12.48 - Initializing modem.
05-27-2004 19:42:12.48 - Send: AT<cr>
05-27-2004 19:42:12.48 - Recv: AT<cr>
05-27-2004 19:42:12.48 - Recv: <cr>
05-27-2004 19:42:12.48 - Interpreted response: Informative
05-27-2004 19:42:12.48 - Recv: <lf>
05-27-2004 19:42:12.48 - Interpreted response: Informative
05-27-2004 19:42:12.48 - Recv: OK
05-27-2004 19:42:12.48 - Interpreted response: Ok
05-27-2004 19:42:12.48 - Send: AT&FE0V1&C1&D2S95=45S0=0<cr>
05-27-2004 19:42:12.48 - Recv: <cr>
05-27-2004 19:42:12.48 - Interpreted response: Informative
05-27-2004 19:42:12.48 - Recv: <lf>
05-27-2004 19:42:12.48 - Interpreted response: Informative
05-27-2004 19:42:12.48 - Recv: AT&FE0V1&C1&D2S95=45S0=0<cr>
05-27-2004 19:42:12.50 - Recv: <cr>
05-27-2004 19:42:12.50 - Interpreted response: Informative
05-27-2004 19:42:12.50 - Recv: <lf>
05-27-2004 19:42:12.50 - Interpreted response: Informative
05-27-2004 19:42:12.50 - Recv: OK
05-27-2004 19:42:12.50 - Interpreted response: Ok
05-27-2004 19:42:12.50 - Send: ATS7=60S30=0L3M1\N3%C3&K3BN1X4<cr>
05-27-2004 19:42:12.50 - Recv: <cr>
05-27-2004 19:42:12.50 - Interpreted response: Informative
05-27-2004 19:42:12.50 - Recv: <lf>
05-27-2004 19:42:12.50 - Interpreted response: Informative
05-27-2004 19:42:12.50 - Recv: <cr>
05-27-2004 19:42:12.50 - Interpreted response: Informative
05-27-2004 19:42:12.50 - Recv: <lf>
05-27-2004 19:42:12.50 - Interpreted response: Informative
05-27-2004 19:42:12.50 - Recv: OK
05-27-2004 19:42:12.50 - Interpreted response: Ok
05-27-2004 19:42:12.50 - Dialing.
05-27-2004 19:42:12.50 - Send: ATDT;<cr>
05-27-2004 19:42:14.18 - Recv: <cr>
05-27-2004 19:42:14.18 - Interpreted response: Informative
05-27-2004 19:42:14.18 - Recv: <lf>
05-27-2004 19:42:14.18 - Interpreted response: Informative
05-27-2004 19:42:14.18 - Recv: OK
05-27-2004 19:42:14.18 - Interpreted response: Ok
05-27-2004 19:42:14.18 - Dialing.
05-27-2004 19:42:14.18 - Send: ATDT####<cr>
05-27-2004 19:42:37.77 - Recv: <cr>
05-27-2004 19:42:37.77 - Interpreted response: Informative
05-27-2004 19:42:37.77 - Recv: <lf>
05-27-2004 19:42:37.77 - Interpreted response: Informative
05-27-2004 19:42:37.77 - Recv: CARRIER 45333
05-27-2004 19:42:37.77 - Interpreted response: Informative
05-27-2004 19:42:37.77 - Recv: <cr>
05-27-2004 19:42:37.77 - Interpreted response: Informative
05-27-2004 19:42:37.77 - Recv: <lf>
05-27-2004 19:42:37.77 - Interpreted response: Informative
05-27-2004 19:42:38.12 - Recv: <cr>
05-27-2004 19:42:38.12 - Interpreted response: Informative
05-27-2004 19:42:38.12 - Recv: <lf>
05-27-2004 19:42:38.12 - Interpreted response: Informative
05-27-2004 19:42:38.12 - Recv: PROTOCOL: LAP-M
05-27-2004 19:42:38.12 - Interpreted response: Informative
05-27-2004 19:42:38.12 - Recv: <cr>
05-27-2004 19:42:38.13 - Interpreted response: Informative
05-27-2004 19:42:38.13 - Recv: <lf>
05-27-2004 19:42:38.13 - Interpreted response: Informative
05-27-2004 19:42:38.13 - Recv: <cr>
05-27-2004 19:42:38.13 - Interpreted response: Informative
05-27-2004 19:42:38.13 - Recv: <lf>
05-27-2004 19:42:38.13 - Interpreted response: Informative
05-27-2004 19:42:38.13 - Recv: COMPRESSION: V.42BIS
05-27-2004 19:42:38.13 - Interpreted response: Informative
05-27-2004 19:42:38.13 - Recv: <cr>
05-27-2004 19:42:38.13 - Interpreted response: Informative
05-27-2004 19:42:38.13 - Recv: <lf>
05-27-2004 19:42:38.13 - Interpreted response: Informative
05-27-2004 19:42:38.13 - Recv: <cr>
05-27-2004 19:42:38.13 - Interpreted response: Informative
05-27-2004 19:42:38.13 - Recv: <lf>
05-27-2004 19:42:38.13 - Interpreted response: Informative
05-27-2004 19:42:38.13 - Recv: CONNECT 45333
05-27-2004 19:42:38.13 - Interpreted response: Connect
05-27-2004 19:42:38.13 - Connection established at 45333bps.
05-27-2004 19:42:38.13 - Error-control on.
05-27-2004 19:42:38.13 - Data compression on.
05-27-2004 20:00:16.66 - Hanging up the modem.
05-27-2004 20:00:16.66 - Hardware hangup by lowering DTR.
05-27-2004 20:00:17.47 - Recv: <cr>
05-27-2004 20:00:17.47 - Interpreted response: Informative
05-27-2004 20:00:17.47 - Recv: <lf>
05-27-2004 20:00:17.47 - Interpreted response: Informative
05-27-2004 20:00:17.47 - Recv: NO CARRIER
05-27-2004 20:00:17.47 - Interpreted response: No Carrier
05-27-2004 20:00:17.47 - Send: ATH<cr>
05-27-2004 20:00:17.47 - Recv: <cr>
05-27-2004 20:00:17.47 - Interpreted response: Informative
05-27-2004 20:00:17.47 - Recv: <lf>
05-27-2004 20:00:17.47 - Interpreted response: Informative
05-27-2004 20:00:17.47 - Recv: <cr>
05-27-2004 20:00:17.47 - Interpreted response: Informative
05-27-2004 20:00:17.47 - Recv: <lf>
05-27-2004 20:00:17.47 - Interpreted response: Informative
05-27-2004 20:00:17.47 - Recv: OK
05-27-2004 20:00:17.47 - Interpreted response: Ok
05-27-2004 20:00:17.47 - 115200,N,8,1
05-27-2004 20:00:17.47 - Session Statistics:
05-27-2004 20:00:17.47 - Reads : 2902336 bytes
05-27-2004 20:00:17.47 - Writes: 166930 bytes
05-27-2004 20:00:17.47 - Serial Overrun Errors: 4
05-27-2004 20:00:17.47 - 56kbps PnP External Fax Voice Modem closed. |
|
| Back to top |
|
|
Robert Nichols
Guest
|
| Posted:
Sat Nov 20, 2004 6:04 pm Post subject:
Re: Confirm: Which is Faster - External Versus Internal Mod |
|
|
In article <419ed936_1@news.tm.net.my>, TE Cheah <no@spam.biz> wrote:
:| an external modem
:| can send and receive no faster than the speed of the serial port to
:| which it is connected (perhaps 115200 bps)
:This is relevant only to ISDN 2 B channel ( 128 kbps ) & above, not to a
:v92 mdm.
Are you claiming that an external modem can somehow push data into the
computer faster than the rate of the serial port used for the
connection?
[SNIP]
:11-20-2004 01:10:03.88 - Connection established at 45333bps.
:11-20-2004 01:10:03.88 - Error-control on.
:11-20-2004 01:10:03.88 - Data compression on.
:11-20-2004 01:21:36.97 - Hanging up the modem.
:11-20-2004 01:21:36.97 - Hardware hangup by lowering DTR.
:11-20-2004 01:21:37.47 - Recv: <cr><lf>NO CARRIER<cr><lf>
:11-20-2004 01:21:37.47 - Interpreted response: No Carrier
:11-20-2004 01:21:37.47 - Send: ATH<cr>
:11-20-2004 01:21:37.98 - Recv: ATH<cr>
:11-20-2004 01:21:37.98 - Recv: <cr><lf>OK<cr><lf>
:11-20-2004 01:21:37.98 - Interpreted response: Ok
:11-20-2004 01:21:37.98 - 460800,N,8,1
:11-20-2004 01:21:38.99 - Session Statistics:
:11-20-2004 01:21:38.99 - Reads : 2249618 bytes
:11-20-2004 01:21:38.99 - Writes: 108550 bytes
OK, that's 2249618 bytes in 693.09 seconds, about 3246 bytes/sec.
[SNIP]
:05-27-2004 19:42:38.13 - Connection established at 45333bps.
:05-27-2004 19:42:38.13 - Error-control on.
:05-27-2004 19:42:38.13 - Data compression on.
:05-27-2004 20:00:16.66 - Hanging up the modem.
:05-27-2004 20:00:16.66 - Hardware hangup by lowering DTR.
[SNIP]
:05-27-2004 20:00:17.47 - 115200,N,8,1
:05-27-2004 20:00:17.47 - Session Statistics:
:05-27-2004 20:00:17.47 - Reads : 2902336 bytes
:05-27-2004 20:00:17.47 - Writes: 166930 bytes
And that's 2902336 bytes in 1058.53 seconds, about 2742 bytes/sec.
Neither of those is even close to being limited by a 115200 bits/sec
serial port or even the raw 45333 bits/sec modem channel. Online
RealVideo is an example of data that is already compressed and cannot be
further compressed by the modem. For that type of data your speed limit
is the 45333 bps modem channel. The serial port just needs to be at
least that fast to keep up. There will be essentially no benefit from
running the serial port faster.
The theoretical limit for a 115200,N,8,1 serial port is 11,520
bytes/sec. If you see rates higher than that, do let me know. And
publish your findings -- I'm sure there are journals that would be
interested. On highly compressible data (an uncompressed news feed)
I've actually seen data rates peaking a little above 10,000 bytes/sec
through a modem on a 115200,N,8,1 serial port. I'd be willing to admit
that the serial port might have been limiting that slightly, but your
2742 bytes/sec rate isn't pushing that limit at all.
--
Bob Nichols AT comcast.net I am "rnichols42" |
|
| Back to top |
|
|
Scott
Guest
|
| Posted:
Sat Nov 20, 2004 11:15 pm Post subject:
Re: Confirm: Which is Faster - External Versus Internal Mod |
|
|
"Bruce Gillis" <brucekg78@yahoo.com> wrote in message
news:2c942c97.0411171107.27fe2a57@posting.google.com...
| Quote: | Hi. I have been pondering my choices for a quality dial-up modem for
my PC. I will be going with the best brand for modems (US Robotics)
but I have come up to a kind of mental stumbling block. As I was
going around the local shops to find the market value of a modem, a
Radio Shack jobber told me that an external modem would hook up with
the Internet a *lot* faster than an internal modem of the same speed
rating and specs (56K; V92).
I was surprised to hear this, but I wasn't convinced so I wanted to
confirm this at another computer store (Computer Resource). There,
the guy told me someting to this effect, "An external modem will be
slower than an internal one and will be three times the cost." Now
everything is so clear!!
Now, I am more confused than ever. I want the fastest 56K modem
around but I am uncertain whether to go with an internal or external
modem. Can someone knowledgeable about modems clarify this for me?
Much appreciated,
Bruce
|
I have both a HaM Intel modem Ambient (which is a The 536EP is a
controllerless (DSP) chipset) and a usr5660a (software modem) both
internals installed. The usr5560a has awful ping for gaming, maybe there's
a better driver by now. I wouldn't recommend the usr one for gaming but it
downloads faster an extra 1.5 meg an hour over the HaM Intel modem I have.
If your a gamer, stay away from the usr5660a software one!! My HaM Intel
one games really good, has excellent ping like 250ms. When I switch over
and try the other usr5660a one, it's like 400ms-450 ms all the time. The
HaM I think usr makes a hardware one for like $45 us or 55 something like
that if you can find it in stores. If your not a gamer then it's just fine
but other's have had problems with the caller id on the usr5660a I've read.
Conclusion, stick with hardware modems I'd say.
Good Luck! |
|
| Back to top |
|
|
Scott
Guest
|
| Posted:
Sat Nov 20, 2004 11:42 pm Post subject:
Re: Confirm: Which is Faster - External Versus Internal Mod |
|
|
I'm not a scientist but wouldn't a good hardware internal modem be slightly
faster then an external just because of the extra communication cables,
maybe, hmm. I'm not really sure, probably about the same or off by a 1 ms.
Another downside it takes up a plug and play slot, an external one. :) |
|
| Back to top |
|
|
Franc Zabkar
Guest
|
| Posted:
Sun Nov 21, 2004 12:28 am Post subject:
Re: Confirm: Which is Faster - External Versus Internal Mod |
|
|
On Thu, 18 Nov 2004 12:50:02 GMT, "MasterBlaster"
<Nobody's.Home@My.Place> put finger to keyboard and composed:
| Quote: | With a few exceptions, most newer internals will be Winmodems.
No brains onboard; Windows & the CPU have to do everything.
Also known as "controllerless" or "software" modems.
|
Actually, there are three types of internal modem, "soft",
controllerless, and "hard" (controller based). Softmodems have a DAA
(telephone line interface), controllerless modems have a DAA and DSP
(digital signal processor), and "hard" modems have a DAA, DSP, and
controller.
Among other things, a modem's controller handles AT command parsing,
UART emulation, data compression and error correction. These functions
do not impact significantly on the host CPU. OTOH, the functions of a
DSP are highly CPU intensive, so a softmodem (which emulates the DSP
in software) may impact noticeably on CPU performance.
Examples of softmodem chipsets are PCtel HSP, Motorola SM56,
Smartlink, and Conexant HSF. Controllerless examples include Conexant
HCF, Intel HaM, Lucent Win Modem, and USR Winmodem.
Note that the term "Winmodem" is a USR trademark and refers to their
line of controllerless modems.
- Franc Zabkar
--
Please remove one 's' from my address when replying by email. |
|
| Back to top |
|
|
Franc Zabkar
Guest
|
| Posted:
Sun Nov 21, 2004 12:28 am Post subject:
Re: Confirm: Which is Faster - External Versus Internal Mod |
|
|
On Thu, 18 Nov 2004 17:44:48 GMT, "GEO" Me@home.here put finger to
keyboard and composed:
| Quote: | On Thu, 18 Nov 2004 04:51:20 GMT, "GEO" Me@home.here wrote:
On 17 Nov 2004 11:07:12 -0800, brucekg78@yahoo.com (Bruce Gillis)
wrote:
Now, I am more confused than ever. I want the fastest 56K modem
around but I am uncertain whether to go with an internal or external
modem. Can someone knowledgeable about modems clarify this for me?
Well, it looks as if you might be better off with an internal modem:
"If your V.92/V.44 modem connects via a 'real' serial port you're in
trouble: most serial ports on PCs aren't able to handle real data
at these rates. The 16550 UART typically found for COM ports is
limited to 115.2kbps - and 20% of that rate isn't data - so, only
92,160bps of data can be achieved on a COM port set at 115.2kbps.
(This can also be a factor with V.42 compression which, as you can see
above, can also produce the potential for >115.2kbps transmission.)
Even a 230.4kbps COM port wouldn't accommodate the throughput I got
on my Softmodem's V.44 46.6kbps connect! Well-designed controllerless
and softmodems aren't only much less expensive than
hardware-controller modems, they can give better performance!"
http://modemsite.com/56k/v92v44v42.asp
HTH
Geo
|
If your ISP supports software compression, then enable it in your DUN
connectoid. Doing so may make the issue of hardware compression moot.
In my case I'm limited to H/W compression using V.90 and V.42bis. With
my DTE speed set to 230400bps I often see data rates in excess of the
standard port rate (115200bps), and occasionally I can achieve
transfer rates as high as 20K bytes/sec.
- Franc Zabkar
--
Please remove one 's' from my address when replying by email. |
|
| Back to top |
|
|
Moe Trin
Guest
|
| Posted:
Sun Nov 21, 2004 5:32 am Post subject:
Re: Confirm: Which is Faster - External Versus Internal Mod |
|
|
In article <419ed936_1@news.tm.net.my>, TE Cheah wrote:
| Quote: | | an external modem
| can send and receive no faster than the speed of the serial port to
| which it is connected (perhaps 115200 bps)
This is relevant only to ISDN 2 B channel ( 128 kbps ) & above, not to a
v92 mdm.
|
Have you disabled data compression on your modem? Even a crappy old v34+
modem (33.6k) can overstuff a 115.2KB serial port. Typical hardware data
compression LIKE v42.bis gives a 4:1 compression of text (data compression
of precompressed stuff is useless - so if you are downloading ZIP files
you are limited by the telephone bit rate over the wire, not the serial
port rate).
| Quote: | For online Realvideo, the size of UART's buffer is relevant, to avoid
*serial overrun errors : my int mdm has 64 byte = end of *.
11-20-2004 01:09:27.37 - Smart Link 56K Voice Modem in use.
11-20-2004 01:09:27.37 - Modem type: Smart Link 56K Voice Modem
11-20-2004 01:09:27.37 - Modem inf path: OEM0.INF
11-20-2004 01:09:27.37 - Modem inf section: Modem1
11-20-2004 01:09:28.07 - 460800,N,8,1
|
and this is setting your serial port to 460.8 KB.
| Quote: | 05-27-2004 19:42:12.26 - 56kbps PnP External Fax Voice Modem in use.
05-27-2004 19:42:12.26 - Modem type: 56kbps PnP External Fax Voice Modem
05-27-2004 19:42:12.26 - Modem inf path: 56KMFG~1.INF
05-27-2004 19:42:12.26 - Modem inf section: Modem51
05-27-2004 19:42:12.48 - 115200,N,8,1
|
where as your older serial port is only being set to 115.2k. If your
external modem can accept the newer faster port rates (230.4KB or 460.8KB)
then you'd benefit by buying a newer serial port. But if you are downloading
compressed trash (such as Realvideo), the data rate is going to be limited
by the wire speed - meaning 53.3 to 56k absolute max no matter which modem
you use or which serial port speed above 56k. .
| Quote: | 11-20-2004 01:09:28.07 - Recv: <cr><lf>OK<cr><lf
11-20-2004 01:09:28.07 - Interpreted response: Ok
|
I just hate this techno-babble. Its only purpose is to confuse the person
trying to read this stuff, and scare away users. It's also about as useful
in debugging a connection as a ten kilo sack of dehydrated sheep droppings.
Old guy |
|
| Back to top |
|
|
TE Cheah
Guest
|
| Posted:
Sun Nov 21, 2004 1:14 pm Post subject:
Re: Confirm: Which is Faster - External Versus Internal Mod |
|
|
| Are you claiming that an external modem can somehow push data into the
| computer faster than the rate of the serial port used for the
| connection?
No, ZDnet's PC Magazine ( USA version ) June'95 issue's article had said
that 115.2 kbps DTE speed is not a bottleneck to any DCE speed <128 kbps
e.g. ISDN 1 B channel's 64 kbps ( however compressible data is ) , let alone
a v92 mdm's maximum 56 kbps.
| that's 2249618 bytes in 693.09 seconds, about 3246 bytes/sec.
What about upload time, servers ( of ISP & websites )' congestion ?
| theoretical limit for a 115200,N,8,1 serial port is 11,520
| bytes/sec.
I think a N,8,1 connection uses only 9 bit per byte. |
|
| Back to top |
|
|
TE Cheah
Guest
|
| Posted:
Sun Nov 21, 2004 1:16 pm Post subject:
Re: Confirm: Which is Faster - External Versus Internal Mod |
|
|
| Have you disabled data compression on your modem?
No, as shown in mdm log.
| Even a crappy old v34+
| modem (33.6k) can overstuff a 115.2KB serial port.
Unless you have a 16650 / 750 / 950 UART & can download ( from a v34
mdm ) more bytes per second than with a 16550 UART, I'll believe ZDnet's
6-95 article. |
|
| Back to top |
|
|
J. Clarke
Guest
|
| Posted:
Sun Nov 21, 2004 9:39 pm Post subject:
Re: Confirm: Which is Faster - External Versus Internal Mod |
|
|
TE Cheah wrote:
| Quote: | | Are you claiming that an external modem can somehow push data into the
| computer faster than the rate of the serial port used for the
| connection?
No, ZDnet's PC Magazine ( USA version ) June'95 issue's article had said
that 115.2 kbps DTE speed is not a bottleneck to any DCE speed <128 kbps
e.g. ISDN 1 B channel's 64 kbps ( however compressible data is ) , let
alone a v92 mdm's maximum 56 kbps.
|
June '95 is ancient history. In 1996 the v.42bis standard was released and
subsequently implemented in nearly all modems. v.42bis provides up to 4:1
compression for some types of data. that means that with a link speed of
56kb the port speed would have to be 224kb.
More recently, v.44 was released, which provides even greater compression.
Since the compression and decompression take place in the modem for a
controller-based modem, the port speed does become the bottleneck.
| Quote: | | that's 2249618 bytes in 693.09 seconds, about 3246 bytes/sec.
What about upload time, servers ( of ISP & websites )' congestion ?
| theoretical limit for a 115200,N,8,1 serial port is 11,520
| bytes/sec.
I think a N,8,1 connection uses only 9 bit per byte.
|
--
--John
Reply to jclarke at ae tee tee global dot net
(was jclarke at eye bee em dot net) |
|
| Back to top |
|
|
|
|
|
|
FAQ
Memberlist
Register
Profile
Log in to check your private messages
Log in