[Beowulf] Cheap SDR IB

Ellis Wilson xclski at yahoo.com
Wed Jan 30 19:01:17 PST 2008


David Mathog wrote:
> Joe Landman <landman at scalableinformatics.com> wrote:
>   
>> Gilad Shainer wrote:
>>
>>     
>>>> IB for gaming?  I have one ratio: 1e-1/3e-6. 
that's human 
>>>> reaction time versus IB latency.
>>>>
>>>>         
>>> Oh yes... I guess you did not play for a long
time. Did you? Talk
>>> with someone who suffer from lagging and you will
get the story, even
>>> When he has a great video card. It's the network
and the CPU overhead
>>> that are the cause of this issue 
>>>       
>> Er... ah ... yeah.  Milliseconds is typical in FPS
games.  hundreds of 
>> ms are bad.  Hundreds of microseconds aren't ...
ok, depends upon your 
>> FPS, I am sure the military folks have *really* fun
ones which require 
>> that sort of latency.
>>     
>
> Many FPS games are still keyboard driven, and the
scan rate on the
> keyboard is likely only on the order of 10Hz. 
Gaming mice scan position
> a lot faster though, last I looked they were closing
in on 10000 data
> points per second. Even so, human reaction time is
now, and probably
> will be forever, at the .1 second level, so even if
that gaming mouse
> could record 1000 button presses a second, no gamer
is ever going to be
> able to push that button at anywhere near that rate.
>
> IB would be massive overkill for gaming, 100 (or
even 10) baseT should
> work just fine unless the network is hideously
congested, in which case
> the game is probably going to become unplayable due
to dropped UDP packets.
>
> Regards,
>
> David Mathog
> mathog at caltech.edu
> Manager, Sequence Analysis Facility, Biology
Division, Caltech
>   
Hate to jump in on this one since its rapidly
approaching "dead horse" 
level, however I have to agree (though without any
nice numeric evidence 
to back) that the very vast majority of gamers will
not benefit from 
this level of latency or bandwidth whatsoever.  This
largely is because 
a vast majority play while connected through their
ISP, not during a 
"LAN party" or the like.  Even at the few occasions of
"LAN parties", 
where the advantages of IB would be (in theory)
realized, many of these 
are simply for companionship and the advantages of
natural 
communication, but still play on a server connected
through the ISP.  
Thus, even to kill the person beside you, a packet
would need to travel 
to the ISP, then the server, any number of
intermediate hops then back 
to you and the opponent.  Obviously, the cost of these
traversal greatly 
outweighs the cost of it coming in through your modem
and being routed 
to your particular PC.

The only interest of mine (because I am unaware to the
differences in 
costs) is the benefit of running a NIC that has the
lowest processing 
overhead.  It could be very possible that the simpler,
older NICs would 
out-perform the more complicated interconnects because
your frames per 
second would be somewhat better, having more PCU
resources oriented 
towards the game.  Again, since I do not have numbers
or knowledge on 
the specifics of various interconnects and their local
NICs costs, this 
is simply speculation.

Though I should chime in since my generation is
typified as being 
addicted to computer games :),

Ellis




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