Experimentation with the quad core Raspberry Pi

[Joost Buijs]

Plus my 20 pound Oscar Cat, angry at me for spending too much time with the machines instead of with him, jumped on my HP 64 bit notebook and then leaped off with his left rear paw ripping off the "W" key, now nowhere to be found.

Maybe he swallowed it.

[sje]

Found the key, and apologized with a can of tuna to Oscar for yelling at him.

It's been hard on the cats today because of the heat. Well after midnight, the place is at 30+ ℃ in spite of the all-day work of my little air conditioner.

Work continues on retreating the HP notebook to Debian 7.8; I hope I don't have to do this more than once.

If I can get the two new Pi2s (rpixx00 and rpix01) configured the way I want and running chess reliably, then they will be joined by rpix02 and rpix03, then maybe rpix04-rpix07, then maybe rpix08-rpix0f, then maybe some day with rpix10-rpix3f. It could take maybe a year for this to complete.

Early tests show that 32 bit PieceSet Oscar runs twice as fast as 64 bit BitBoard Symbolic on the new Pi2s.

[Joost Buijs]

Out of curiosity I ordered one of these: Qualcomm Dragonboard 410C.
https://developer.qualcomm.com/hardware ... board-410c

It is a 64 bit RPI compatible device with a Cortex A53 CPU, 4 cores at 1.2 GHz. It costs $75,-

It only has WiFi and no physical network interface, for my tests it will be ok, but it is a big problem if you want to build a cluster with these devices.

I expect it to give me about twice the performance for my engine compared to the RPI2B. (64 vs 32 bit and 33% higher clock).

At the moment these are only sold by Arrow in the USA and there were quite some shipping costs added.
I suppose it is just a matter of time before they start selling these in my country as well.

[sje]

The lack of an Ethernet port can be resolved with a USB->Ethernet adapter -- at extra cost. But at US$70, the Qualcomm board already has enough extra cost.

[bnemias]

The lack of an Ethernet port can be resolved with a USB->Ethernet adapter -- at extra cost. But at US$70, the Qualcomm board already has enough extra cost.

Tempting. Lack of ethernet is quite irritating. However it does come with 8G eMMC and a P/S. I'd like to replace my old kirkwood home server with something like this, but lacking ethernet... i dunno. But I suspect I could run zerowin (FICS) on just one core and it'd be a lot stronger.

I didn't see any cases for it. That's a must if I'm going to convert it into a server.

[Joost Buijs]

Although the company says on their website that they have in stock, I just got an email that it will take at least 10 days before they can ship it.
So I have to wait somewhat longer.

[sje]

I am convinced that the best way to fix a Debian 8.0/8.1 install is to re-install Debian 7.8 which will fix many things.

What remains no-good is getting a USB WiFi adapter using a RealTek chip working on a desktop running any Linux version. I have spent hours on this and will now use an alternate approach of a WiFi network extender which has four 10baseT jacks.

I still haven't done much with getting a USB WiFi adapter working on a Pi or on the BeagleBone Black.

[sje]

I managed to get an Ourlink USB WiFi adapter working on a BeagleBone Black, and with a static IP as well. But I haven't yet figured out how to make the phony usb0 dhcp interface to not be installed. This is not critical, but it is sloppy.

The decent adapter:

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Earlier I had tried a similar but super miniaturized adapter with the same RT8818CUS chip; it wasn't even recognized by the lsusb command. This was probably because the adapter was defective; when I removed it from the board's USB part, it fell apart in my hand. Twelve bucks down the drain.

The crap adapter, do not buy:

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The single core 32 bit BB Black runs the BusyFEN benchmark at about 275 KHz which is not too bad for a system which can be powered by a 9 V battery.

But the BB Black has been around a while, and given the competition from the Pi2, the Black needs a much better CPU to keep up in the marketplace.

[sje]

Symbolic vs Oscar on the BB Black

Symbolic, using bitboards, runs the BusyFEN benchmark on the single core, 32 bit 900 MHz BeagleBone Black at a rate of about 275 KHz. Oscar, using 32 bit piece sets, gets about 560 KHz -- just over twice as fast. While Oscar was designed from the start to be primarily a perft() program, like Symbolic it does a lot of general chess work and uses 128 bit signatures.

I haven't yet run four threads of Oscar on the Pi2; I estimate it'll run BusyFEN at just over 2 MHz.

[Joost Buijs]

Still waiting on that Dragonboard to be shipped.
When I ordered it (and paid for it), it was supposed to be in stock.
The company doesn't even reply to my inquiries.
I thought Arrow Electronics is a reliable company to deal with.