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/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. > 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 _______________________________________________ Freedos-devel mailing list Freedos-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-devel
