SH4 DMAC demo

test kos 1.2 (build gcc-3.0.4) linux

gcc-3.0.4

Quote:

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test memory Sh4->PVR

51342 ms dmac 32bit mode

16296 ms dmac 256bit mode

40772 ms cpu loop

16319 ms sq loop

6241 ms dma loop

test memory Sh4->Sh4

8920 ms dmac 256bit copy loop

18966 ms CPU 32bit copy loop

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gcc -3.4.4

Quote:

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test memory Sh4->PVR

51341 ms dmac 32bit mode

16296 ms dmac 256bit mode

40744 ms cpu loop

16319 ms sq loop

6262 ms dma loop

test memory Sh4->Sh4
no work

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Quote:

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Originally Posted by Morph

It may be possible that you get different results based on the hardware revision you use it on.

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I've always pondered over writing some sort of benchmark suite for the DC to determine the differences between the two SH4s used in them. According to Rensas(sp?) (whom I emailed about the question) the DC's second version of SH chip was a revision made for heat and energy efficiency, so benchmarks with it might be slightly different.

True, and making it heat and energy efficient doent necessarily make it mroe powerful. Heck, for the 5GHz project, they used a Northwood Pentium 4, which was actually an older core by then.

Supplied .elf:

Quote:

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test memory Sh4->PVR

50478 ms dmac 32bit mode

15494 ms dmac 256bit mode

39055 ms cpu loop

15519 ms sq loop

6081 ms dma loop

test memory Sh4->Sh4

8920 ms dmac 256bit copy loop

18967 ms CPU 32bit copy loop

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GCC 3.4.4:

Quote:

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test memory Sh4->PVR

50470 ms dmac 32bit mode

15488 ms dmac 256bit mode

39019 ms cpu loop

15511 ms sq loop

6100 ms dma loop

test memory Sh4->Sh4
(..HANG..)

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EDIT: The Sh4->PVR times I get differ from what other people have reported so far.

benchmarks are great and it makes fun to test aganst different compiler ..and so on.

but it would be great if some one use DMAC /PVR DMA in a original dreamcast homebrew project.


well that gcc 3.4.x does not work with the DMAC demo....this is not a suprise to me. cause I had also problems with GCC >3.3.5