On at 2023-04-04 21:09 +0200, tom ehlert wrote:
Dear Bret,
The article is found at
https://pushbx.org/ecm/dokuwiki/doku.php?id=blog:pushbx:2023:0321_cpu_performance_comparison
I mostly agree with you and your article, but:
fine that you agree, but at most 50% of the article is even close to
'right'.
Conclusion
CPU-bound benchmarks are much faster on a modern machine than they
are on older ones.
The frequency increase does not actually suffice to explain the
speedup.
Some things, like doing I/O, were not sped up nearly as much
however.
I tried posting a much longer response to this, but it was
apparently rejected by the moderators. Here's a shorter one.
I don't think that the mailing lists are moderated that way? Anyway,
Bret, you can send any additional comments to me per email or as a
comment on the blog.
I/O has also vastly speedup (we have SSD speeds of up to 6 GB/sec).
Just not by doing IN/OUT, but by using memory mapped PCI devices.
I think you're confusing two different things -- MMIO and DMA/Bus-Mastering.
He is NOT.
Who's "he"? In case this was meant to refer to me, it is wrong because
I'm not a "he".
Whether I/O is PMIO or MMIO is pretty much irrelevant to the speed.
For example, I/O port 201h (the analog joystick) and I/O port 92h
(which controls A20 on some computers) are both VERY slow and would
not be any faster if they were MMIO instead of PMIO.
this is plain bullshit.
The speed depends on the I/O device, not the type of I/O mapping.
which is nonsense.
Plus, I/O
_can't_ be cached, whether PMIO or MMIO, so the cache(s) are irrelevant to I/O.
yes. I/O device data can't be cached. you are such a clever person to
discover this fact. WOW.
SSD speeds are fast because they use bus-mastering, not because
they use MMIO. The I/O ports are used to "control" the device, but
the data from the SSD is transferred in and out of RAM using
bus-mastering (which is fast because it doesn't use the CPU at all).
I understand that you don't have the faintest clue how modern PCI devices
work. Just go ahead with undertaining us ...
Tom
Regards,
ecm
_______________________________________________
Freedos-devel mailing list
Freedos-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/freedos-devel
