D vs. C#

[David Wilson]

On 23/10/2007, 0ffh <spam at frankhirsch.net> wrote:
> Walter Bright wrote:
> > It sounds like they discovered that fast hardware (a fast desktop
> > machine) runs faster than slow hardware (small embedded system)! But it
> > doesn't sound like on the same machine they showed that software ran
> > faster than hardware.
>
> It sounds like they discovered, that for any resonable amount of money to
> spend on hardware, they'd be better of with cheap, fast, but "wrong" off-
> the-shelf hardware and software emulation than with some expensive custom
> made piece of metal that runs their stuff natively.

This is *not* the case. Current hardware virtualization cannot reach
the performance of software paravirtualization for various reasons.
Hardware nested page table support being the most often mentioned -
many common ops are still very expensive under current
Vanderpool/Pacifica, some worse than cooperative virt. See e.g.
http://project-xen.web.cern.ch/project-xen/xen/hardware.html (search
for "memory management").

Current virtualization hardware tech was pushed out the door to take
advantage of the virtualization bubble last year/two ago. It is very
wrong to assume that just because there is "hardware support" it's
going to be "faster" (for some easily quantifiable value of faster),
useful, or both.

Thanks,


David.
"A little knowledge is dangerous"

>
> Regards, Frank
>