[Hardware] The market of ASICs (One GigaKey / Second?)

Dan Oetting dan_oetting at uswest.net
Tue Aug 10 01:51:13 EDT 2004


On Aug 9, 2004, at 10:14 PM, Elektron wrote:

>
> On 10 Aug, 2004, at 09:16, Dan Oetting wrote:
>
>> Why so slow! I get 16 bytes in 17 cycles on a G4. I was all excited 
>> until I found out that IBM apparently already had a patent on the 
>> method and it couldn't actually run that fast because it is limited 
>> by the memory bandwidth.
>
> Using tables or not? I found that using a 12-bit table was fastest, 
> since a 16-bit table can't fit in my L1 cache.

Anything larger than a 8 bit table gets real tricky in AltiVec so I 
don't use it except for the cleanup. The main loop is just a little bit 
of polynomial arithmetic which goes real fast when you have 128 bit 
registers.

> I wasn't aware that you could patent CRC either.

In the US you can patent anything.



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