OT Linux (RE: [rescue] OT: Stuffed Proliant?)
Joshua D Boyd
rescue at sunhelp.org
Sat Dec 22 13:08:28 CST 2001
On Sat, Dec 22, 2001 at 02:25:35AM -0500, Patrick Giagnocavo wrote:
> Actually, you could probably get better performance from other
> platforms, but it is easier to solve problems with more RAM, which is
> cheap on x86. DBMS's luuuuuve more RAM.
Absolutely. But ram for modern Suns isn't so bad. Don't the netras use
standard PC100 ram? Or is that only the SB100s.
> All I know is that many people were very happy that the crypto add-in
> cards got supported in OpenBSD and Linux, etc. Could also be for
> IPSEC/VPN usage though.
Yeah, but they were happy about those cards even for intel systems.
>> Besides, lack of rotate isn't all that bad. Instead of rotating left by 12
>> bits, you shift left by 12, shift right by 20, then sum the two shifts. The
>> two shifts can be done simultaneously on a super-pipelined processor, so you
>> need 3 cycles to do a rotate instead of one. While this seems bad, I find it
> As long as the cache stays full...
Well, of course.
>>hard to believe that this is the sole reason for distributed net to be slower
>>on SPARCs than intel boxes. We loose 2 cylces on a rotate. So what. We
>>make it up by doing less loads.
> Maybe loads aren't as expensive when everything is in L2 cache.
No, they aren't as expensive, but they still take a minimum of 1 cycle.
So, doing fewer loads still might balance it out.
I've heard lots of arguments about why Intel is better for encryption, and the
numbers seem to support it, but I really want to know why before I just give
in. It's not like it really should be that hard for someone to make a
definative write-up on the topic, if they just take the time to look at the ASM
and count CPU cycles.
Joshua D. Boyd
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