  cacophony777
@comcast.net
| [Cable] Why does my Mac get 4x the bandwidth ?
Hi,
I just upgraded to Comcast Cable's 6Mbit plan (with 12 Mbit powerboost). I have three computers (all wirelessly connected to the same router) which are consistently demonstrating the following bandwidth discrepancy:
1) Windows XP pro laptop : 5 Mbit down 2) Windows XP pro desktop : 5 Mbit down 3) Macbook Pro laptop : 20 Mbit down (!)
I've just spend the last couple hours trying to tweak my Windows XP laptop but have had no luck getting the bandwidth to increase. I ran the SG TCP Optimizer for example (I'll copy the changes it made at the end of this post). I just can't understand why the Mac laptop is so much faster...
Here are the answers to the initial questions for my Windows laptop:
1) »/tweakr/block:···a=normal
2) speed Test #49695790 by dslreports.com Run: 2008-04-24 00:56:29 EST Download: 4726 (Kbps) Upload: 1539 (Kbps)
The Mac consistently gets download speeds around 20,000Kbps!
3) Wouldn't let me do (not a member)
4) I have Comcast Cable (modem shouldn't matter b/c I'm getting great speeds with the Mac)
5) n/a
6) n/a
7) Windows XP Pro
8) 6 Mbit (12 Mbit powerboost)
9) No connection sharing or VPN
10) Using WRT54G wireless router
11) n/a
------------
[SYSTEM\CurrentControlSet\Services\Tcpip\Parameters] TcpWindowSize=256960 GlobalMaxTcpWindowSize=256960 EnablePMTUDiscovery=1 EnablePMTUBHDetect=0 SackOpts=1 DefaultTTL=64 TcpMaxDupAcks=2 Tcp1323Opts=1 DisableUserTOSSetting=-1 DefaultTOSValue=-1 [SYSTEM\CurrentControlSet\Services\Afd\Parameters] DefaultReceiveWindow=-1 [Software\Microsoft\Windows\CurrentVersion\Internet Settings] MaxConnectionsPerServer=10 MaxConnectionsPer1_0Server=10 [SYSTEM\CurrentControlSet\Services\ICSharing\Settings\General] InternetMTU=-1 [SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\RemoteComputer\NameSpace\{D6277990-4C6A-11CF-8D87-00AA0060F5BF}] {D6277990-4C6A-11CF-8D87-00AA0060F5BF}=-2 [SYSTEM\CurrentControlSet\Services\Dnscache\Parameters] MaxNegativeCacheTtl=0 NegativeCacheTime=-1 NetFailureCacheTime=0 NegativeSOACacheTime=0 [SOFTWARE\Policies\Microsoft\Windows\Psched] NonBestEffortLimit=-2 [SYSTEM\CurrentControlSet\Services\Tcpip\ServiceProvider] LocalPriority=5 HostsPriority=6 DnsPriority=7 NetbtPriority=8 [System\CurrentControlSet\Services\LanmanServer\Parameters] SizReqBuf=16384 [SYSTEM\CurrentControlSet\Services\NdisWan\Parameters\Protocols\0] ProtocolMTU=1500 [SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\{D37167D0-E65B-463B-94EC-217F4CBCE836}] MTU=-1 TcpWindowSize=-1 [SYSTEM\CurrentControlSet\Services\Psched\Parameters\Adapters\{D37167D0-E65B-463B-94EC-217F4CBCE836}] NonBestEffortLimit=-1 [SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\{0719BB45-D044-4545-8442-1A577D223FAF}] MTU=1500 TcpWindowSize=-1 [SYSTEM\CurrentControlSet\Services\Psched\Parameters\Adapters\{0719BB45-D044-4545-8442-1A577D223FAF}] NonBestEffortLimit=-1 [SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\{F110305D-3979-4D30-92AC-B2C1F4AAC9CD}] MTU=1300 TcpWindowSize=-1 [SYSTEM\CurrentControlSet\Services\Psched\Parameters\Adapters\{F110305D-3979-4D30-92AC-B2C1F4AAC9CD}] NonBestEffortLimit=-2 [SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\{130AA788-46CD-4400-94A5-AEB57884FFA9}] MTU=-1 TcpWindowSize=-1 [SYSTEM\CurrentControlSet\Services\Psched\Parameters\Adapters\{130AA788-46CD-4400-94A5-AEB57884FFA9}] NonBestEffortLimit=-2 [SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\{BB1BB564-A084-475B-9653-CD44EB765399}] MTU=1300 TcpWindowSize=-1 [SYSTEM\CurrentControlSet\Services\Psched\Parameters\Adapters\{BB1BB564-A084-475B-9653-CD44EB765399}] NonBestEffortLimit=-2 [SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\{92D21647-46A9-4E41-8D12-B57260949A25}] MTU=-1 TcpWindowSize=-1 [SYSTEM\CurrentControlSet\Services\Psched\Parameters\Adapters\{92D21647-46A9-4E41-8D12-B57260949A25}] NonBestEffortLimit=-1 [SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\{39DAF23D-DE3E-442F-ADA0-FBD364A9AC4B}] MTU=-1 TcpWindowSize=-1 [SYSTEM\CurrentControlSet\Services\Psched\Parameters\Adapters\{39DAF23D-DE3E-442F-ADA0-FBD364A9AC4B}] NonBestEffortLimit=-1 |
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  Irish Shark Play Like A Champion Today Premium,MVM join:2000-07-29 Las Vegas, NV | Try an RWIN of 64240 and see what that does. |
|
  cacophony777
@comcast.net | I tried that RWIN value and it made no difference. Any other ideas? |
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  Ikyuao debian linux power
join:2007-02-26 Wichita, KS edit: June 14th, @02:16PM
| reply to cacophony777 64K RWIN is too small and inefficient for most high bandwidth bandbroad connection (cable, DSL T1, T3, fiber etc) this present today. |
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  Irish Shark Play Like A Champion Today Premium,MVM join:2000-07-29 Las Vegas, NV
| said by Ikyuao :64K RWIN is too small and inefficient for most high bandwidth bandbroad connection (cable, DSL T1, T3, fiber etc) this present today. No it is not. It depends on your line rate. -- "You can observe a lot by watching". Yogi Berra |
|
  Ikyuao debian linux power
join:2007-02-26 Wichita, KS
·Cox HSI
edit: June 14th, @04:04PM
| said by Irish Shark :said by Ikyuao :64K RWIN is too small and inefficient for most high bandwidth bandbroad connection (cable, DSL T1, T3, fiber etc) this present today. No it is not. It depends on your line rate. What if cable companies keeps increasing more bandwidth in future? Comcast have promised to increase to 100Mbits broadband in 2010? Then 64K RWIN buffer is too small and inefficient that's it. That is not about local area network, It is about wide area network as internet. |
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  Irish Shark Play Like A Champion Today Premium,MVM join:2000-07-29 Las Vegas, NV | When 100mb/s comes around, then go nuts on the RWIN. Right now 64240 is plenty in many cases.
BTW, RWIN has nada to do with a LAN - it is an Internet only setting. -- "You can observe a lot by watching". Yogi Berra |
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  Ikyuao debian linux power
join:2007-02-26 Wichita, KS
·Cox HSI
edit: June 14th, @04:41PM
| What if I start with pinging to google site? that would be 1ms RTT traveling through routers of internet that would be overkill that is not happening, Irish. Most of internet does 50ms RTT to 100ms RTT that 64K RWIN is still small buffer and inefficient for speed of internet bandwidth so get a clue. Come on it's a truth, dude.
That is no 1ms RTT that means 64K RWIN buffer is not enough at 50ms RTT or above across routers of internet. |
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  RedXII1234 Premium,Mod join:2001-02-26 localhost | (topic move) [Cable] Why does my Mac get 4x the bandwidth ?
Moderator Action The post that was here (and all 12 followups to it), has been moved to a new topic .. »[Cable] Why does my Mac get 4x the bandwidth ? |
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