DragonFly users List (threaded) for 2005-04
Re: xorg +XGI Volari XP5
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Hummel Tom wrote:
> Numbers? I think "running circles" is unlikely.
I don't have any numbers yet on the Turion64 specific, but it's just a
Athlon64 with some adjustments so you can make pretty solid claims about
Turion64 performance when you compare the Athlon64 with the Pentium-M.
> <snippety snap>
The difference here is between measured thermal power dissipation when
running a certain task (i.e. BurnK7), and maximum thermal power
dissipation. First, I measured total CPU power usage. Second, a task
like BurnK7 never stresses the CPU to it's fullest. A large part of the
CPU die consists of cache (L1, L2) which gets little to do when running
a synthetic 'benchmark' like BurnK7. With intensive cache invalidation
and reloading action, a lot of energy is consumed, and logically a lot
of heat generated. Third, of course you can't ever get the caches to
update completely every clock cycle, due to memory slowness and the
serial nature of cache invalidation in current x86 (and other?) CPU
designs (which results in cache invalidation taking a lot of CPU cycles).
However, in this field politics are concerned as well. There is truth in
your words about differing policies on TDP values for both AMD and
Intel, but you look the wrong way. AMD actually specifies a true real
maximum TDP, whereas Intel specifies an average maximum TDP based on
stresstests. However, this doesn't mean AMD rates it's TDP too high, but
rather Intel too low.
-- Thomas E. Spanjaard