Yeah… I didn’t find that site very helpful and I’ve spent a lot of time on linux-sunxi.org over the years. The D1 seems to be very much a mystery compared to the other Allwinner SOCs. But I do see where you get the “alphabet hash” from. I still have a lot of reading to do on the docs that I’ve downloaded from there.
One thing that is obvious from that page is that there is a lot more video hardware that isn’t getting used. Is this because the drivers aren’t available or is there some other reason? I get that it doesn’t support OpenGL… But it does support things like screen rotation in hardware… which would speed the display up quite a bit.
I doubt this. Finding primes is purely compute bound and D1 has 32K ICache + 32K DCache. As @Godzil mentioned it’s more likely to be about the pipeline and the ability to do superscalar stuff.
A72 is out of order superscalar 15 stages.
A53 is in order superscalar 8 stages.
A7 is in order superscalar 8 stages.
D1 is in order superscalar (claims 4GFlops) 5 stages.
ref:
The other issue is the quality of the compiler. It may or may not be able to do vectorization efficiently.
On the other hand, D1 does pack a punchy DSP core in there (D1s doesn’t have it, but D1s has 64MB fixed ddr2 ram so it’s likely R01 has the “full” D1?)… I’m very interested in testing some floating point MACs
You’re right! Which is why I suspect(ed) the RAM data bus. But as I mentioned above while its only half the speed of the A64 (ARM64 @ 1.1GHz) but at least twice as fast as the R8 (ooold ARM32 @ 1GHz) it doesn’t explain why the R8 can compile a small library twice as fast. mbw demonstrated that the impact of a 16bit RAM bus is that its half as fast as the A64, 32bit RAM bus. So it IS a significant performance hit.
Since the R8, which compiles twice as fast as the D1, is twice as slow in both RAM and storage, and since execution speed of general operations in the D1 core is comparable to the A64, which is also faster at the compile task, this really only leaves one thing:
gcc / g++, NOW with “super-slow 100x” added! Get your’s today!
I’m still looking for a way to prove this. But since the RISC-V is so new I have very few precompiled options. Running g++ 9 as opposed to 10 gave me 10sec or about a 9% speed increase. The A64 is running g++ v8.3.0 so to test my hypothesis I need to compile that version for RISC-V, assuming there was even support for the architecture back then.
So! Since in my mind this is pretty much settled, and since compiling the GCC is only for those who love to program in “malbloge”, and since the option may not even be available, and since I really want to be able to do things with my R-01 DevTerm… this is back-burnered until I get another idea and / or some slack time.
Thanks for that reveiw! I’ve thought about getting the RISC processor just to experiment but not sure what software packages will run on it - I purchased the A06 processor - I Don’t play games but I do use it for SDR and some Ham radio applications.
I’m getting my technician radio license in June, and hopefully my general later this summer. I was hoping to use my uconsole for some radio stuff, but I ordered the r01, I may have to order something less interesting if I’m actually gonna use this thing
I use a Panasonic Toughbook I loaded with Linux … and a windows 10 laptop for Winlink (email over radio) the tough book is useful for digital radio communication and so much more - it ran windows 7, but is blazing fast running the i86 version of Raspian… also it has a SSD drive…
excellent question! No helpful constructive criticism offends - personal preference mostly (user skill level another good reason) but the Raspberry pi OS experience on a non raspberry pi device means my build instructions are mostly hardware independent. I would suggest users pick an Linux varient and kind of stick with it. long time ago it was Debian - DSL (Damn Small Linux) a time spent with Knoppix (I like the Live versions) on older machines but since I’ve done so much with Pi"
's i like the common interface of the Raspian distribution. Also there is a HamLib distribution for the Pi but ive had trouble installing… so i do a standard install of Raspbian then follow build note to install the packages I Need [quote=“wdouglass, post:27, topic:8641, full:true”]
If you’re on x86 why raspbian? why not base debian?
not criticizing, just curious
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Which is why I suspect(ed) the RAM data bus. But as I mentioned above while its only half the speed of the A64 (ARM64 @ 1.1GHz) but at least twice as fast as the R8 (ooold ARM32 @ 1GHz) it doesn’t explain why the R8 can compile a small library twice as fast.