That's download speed. Comcast just took over in my area from previous cable TV/ISP Matrix, but I have been on Verizon DSL for several years, so never had any experience with the prior cable modem service here. Semi-rural area between San Jose and Santa Cruz CA, yes the mountains.

The line comes off the pole into a 2 GHz splitter that the first tech installed. The line to the pole was not replaced upon installation, however the 2nd guy did say "the fittings were really old so I replaced them and I also removed an old filter up there". The filter was probably from the previous CATV provider to block the premium channels.

www.speedtest.net originally reported my download speed at 500k. Since then, it's all over the map, currently SLAMMING at about 50k. I am not kidding. FIFTY you heard right FIFTY. I am of course, being facetious when I say slamming.

Now, a friend who lives across the canyon, also just got Comcast, same deal, etc and SpeedTest website shows her connection absolutely smokin (really) at 16000 k on average. Upload here is 500k to 1200k which is fine, as it's rated for 384 I can't complain about that, but the name of the game is DOWNLOAD folks, at least for me, most of the time.

Even Verizon DSL gets above 600k on a rated 784k connection.

Comcast online techs twice said "your signal level here shows as IDEAL".

From the modem I am going into a Belkin router and then across the ceiling to an SMC 1000/100/10 8 port switch, then to my PC. No wireless, well the Belkin is a wireless modem but the path to the PC is wired.

Even when I plugged right into the modem the speeds never got over about 1000k.

The modem signal page shows:

Downstream Value
Frequency 549000000 Hz
Signal To Noise Ratio 30.4 dB
Power Level -5.4 dBmV

Upstream Value
Channel ID 1
Frequency 30000000 Hz
Power 45.3 dBmV

Modem is Motorola SB5101. Other interesting scraps from the modem config:

Task Status
Acquire Downstream Channel Done
Obtain Upstream Parameters Done
Upstream Ranging Done
Establish IP Connection Using DHCP Done
Establish Time of Day Done
Transfer Operational Parameters Through TFTP Done
Register Connection Done
Cable Modem Status Operational
Initialize Baseline Privacy Done

Item Value
Frequency Plan North American Standard/HRC/IRC
Upstream Channel ID 1
Frequency (Hz) 549000000
DHCP Server Enabled

Time Priority Code Description
2007-11-23 14:29:07 3-Critical R005.0 Started Unicast Maintenance Ranging - No Response received - T3 time-out
2007-11-23 12:49:19 4-Error E107.0 SW upgrade Failed after download - Incompatible SW file
2007-11-23 12:49:15 6-Notice E102.0 SW Download INIT - Via Config file d11_m_sb5100_silver_c01.cm
1970-01-01 00:00:11 3-Critical D003.0 DHCP WARNING - Non-critical field invalid in response.
2007-11-23 12:37:58 6-Notice E102.0 SW Download INIT - Via Config file d11_m_sb5100_silver_c01.cm
1970-01-01 00:00:12 3-Critical D003.0 DHCP WARNING - Non-critical field invalid in response.
2007-11-22 08:29:41 3-Critical R004.0 Received Response to Broadcast Maintenance Request, But no Unicast Maintenance o
2007-11-22 08:29:41 3-Critical T002.0 SYNC Timing Synchronization failure - Failed to acquire FEC framing
2007-11-22 07:48:10 3-Critical R005.0 Started Unicast Maintenance Ranging - No Response received - T3 time-out
2007-11-22 00:29:00 4-Error E107.0 SW upgrade Failed after download - Incompatible SW file
2007-11-22 00:28:56 6-Notice E102.0 SW Download INIT - Via Config file d11_m_sb5100_silver_c01.cm
1970-01-01 00:00:12 3-Critical D003.0 DHCP WARNING - Non-critical field invalid in response.
2007-11-16 08:25:17 3-Critical R004.0 Received Response to Broadcast Maintenance Request, But no Unicast Maintenance o
2007-11-16 08:25:17 3-Critical T002.0 SYNC Timing Synchronization failure - Failed to acquire FEC framing
2007-11-16 08:24:15 3-Critical R005.0 Started Unicast Maintenance Ranging - No Response received - T3 time-out
2007-11-15 23:18:17 4-Error E107.0 SW upgrade Failed after download - Incompatible SW file
2007-11-15 23:18:10 6-Notice E102.0 SW Download INIT - Via Config file d11_m_sb5100_silver_c01.cm
1970-01-01 00:00:12 3-Critical D003.0 DHCP WARNING - Non-critical field invalid in response.
2007-11-15 22:04:08 6-Notice E102.0 SW Download INIT - Via Config file d11_m_sb5100_silver_c01.cm
1970-01-01 00:00:10 3-Critical D003.0 DHCP WARNING - Non-critical field invalid in response.
2007-11-15 19:21:56 6-Notice E102.0 SW Download INIT - Via Config file d11_m_sb5100_silver_c01.cm
1970-01-01 00:00:11 3-Critical D003.0 DHCP WARNING - Non-critical field invalid in response.
2007-11-15 19:17:14 3-Critical R005.0 Started Unicast Maintenance Ranging - No Response received - T3 time-out
2007-11-15 12:02:21 5-Warning D103.0 DHCP RENEW WARNING - Field invalid in response
2007-11-15 12:00:48 3-Critical R005.0 Started Unicast Maintenance Ranging - No Response received - T3 time-out
2007-11-15 11:39:15 4-Error E107.0 SW upgrade Failed after download - Incompatible SW file
2007-11-15 11:39:13 6-Notice E102.0 SW Download INIT - Via Config file d11_m_sb5100_silver_c01.cm

I'm also going through the TCP Optimize program to see if that helps at all, but 50k, come on, that is seriously off.