Network Throttling Index (from speedguide.net)
 By default, Windows  Vista/7 implements a network throttling mechanism to restrict the  processing of non-multimedia network traffic to 10 packets per  millisecond (a bit over 100 Mbits/second). The idea behind such  throttling is that processing of network packets can be a  resource-intensive task, and it may need to be throttled to give  prioritized CPU access to multimedia programs. In some cases, such as  Gigabit networks and some online games, for example, it may be  benefitial to turn off such throttling all together.
 
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Multimedia\SystemProfile
NetworkThrottlingIndex=ffffffff  (DWORD, default: 10 hex, recommended: 10 hex for media sharing, ffffffff for gaming and max throughput, valid range: 1 through 70 decimal or ffffffff to completely disable throttling)
 It is only recommended to change this setting in saturated Gigabit LAN  environments, where you do not want to give priority to multimedia  playback. Reportedly, disabling throttling by using ffffffff can also  help reduce ping spikes in some online games.
 Notes:  Setting is available in Windows 7, Vista (SP1), 2008 Server. Default  value is 10 under Windows 7, similar behavior if the setting is not  present in the Registry.
Games that may be affected by this throttling: Source Engine games (TF2, Left 4 Dead, CS:S), HoN, CoD, Overlord series.
 Reference: 
MSKB 948066
			
		 
	
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