Rasberry PI 2 ?

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UKenGB
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Rasberry PI 2 ?

Post by UKenGB » Mon Sep 14, 2015 2:45 pm

Do you think MM2 could run on an RP2 - and be useful as a MythTV frontend of course?

It's an obvious choice if it works satisfactorily, i.e. is fast enough, because they're cheap, readily available, small and diskless and ideal - if they've got sufficient horsepower. Has this been tried?

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warpme
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Re: Rasberry PI 2 ?

Post by warpme » Mon Sep 14, 2015 7:39 pm

Well,
Key differentiators of MM2 over other disk-less alternatives are:
1.Very simple install (only copy of 2 files + some TFTP/DHCP/HTTP config changes)
2.Full plug-and-play
3.PXE boot with RAMdisk based root FS

For me 3 has advantage over alternatives like NFS root based solutions (i.e. LTSP https://www.mythtv.org/wiki/Diskless_LTSP_Frontend) because it maximizes speed as root FS. It has RAM speed - instead of network speed.
I see clear benefit on platforms like ION1 (where effective network speed is only 600-800Mbps on GE) - especially on UI responsivnes as mythtv images cache/theme cache are in RAM.

Regarding PI2 I see following issues not allowing to keep MM2 diferentiators:
1. PXE boot: PXE is an X86 only BIOS thing. AFAIK it's not specifically available on ANY ARM based machine.
2. RAM: RAMdisk needs RAM. Currently MM2 needs 460MB of RAM for rootfs RAMdisk. For heavy 1920x1080 theme MythTV can consume over 1G RAM. 1G of on-board PI2 RAM is way too small.

Also PI2 will have video HW decode issue: MythTV isn't supporting OpenMAX API to PI2 GPU - so all video playback will be in software decode.
This I believe will not work at all for HD content...

br

UKenGB
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Re: Rasberry PI 2 ?

Post by UKenGB » Tue Sep 15, 2015 8:02 am

OK, no good then. I'll search for some ION based alternatives.

Would I be right in thinking that ION2 would be better than ION1?

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warpme
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Re: Rasberry PI 2 ?

Post by warpme » Wed Sep 16, 2015 3:58 pm

UKenGB wrote:OK, no good then. I'll search for some ION based alternatives.

Would I be right in thinking that ION2 would be better than ION1?
Oh this is not obvious:
ION1
+GFX to CPU via fast DMI
-Nvidia9400M (gfx in ION1) can't HW decode DIVIX
-Nvidia9400M (gfx in ION1) can't do Advanced 2x HW DI

ION2
-GFX to CPU via slow PCI-e x1 lane
+GT218 (gfx in ION2) can HW decode DIVIX
+GT218 can do Advanced 2x HW DI

Personally DMI vs PCI-e x1 lane makes bigger difference than DVIX/2xHW DI for me - so paradoxically I would opt for ION1...

Damn Intel revoke DMI licence for Nvidia after significant success of ION1....

UKenGB
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Re: Rasberry PI 2 ?

Post by UKenGB » Wed Sep 16, 2015 4:04 pm

So who's got a stack of ION1 based machines available to sell at wonderfully cheap prices?

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Re: Rasberry PI 2 ?

Post by UKenGB » Wed Sep 16, 2015 6:59 pm

So would I be correct in thinking that the Acer Aspire Revo is a good choice for MM2?

Anyone know the difference between the R1600 and the R3600?

The R3700 is ION2 therefore not ideal.

So the R3610 looks to be the best option? Dual core CPU, so more grunt, but still ION1 graphics. The best choice?

Would the above and also an ASUS EEEBox boot from the same MM2 image, or would they have to different? I just want a single network image so do I need to stick to the exact same box or could they all run from the same network files?

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warpme
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Re: Rasberry PI 2 ?

Post by warpme » Thu Sep 17, 2015 9:10 am

UKenGB wrote:So would I be correct in thinking that the Acer Aspire Revo is a good choice for MM2?

Anyone know the difference between the R1600 and the R3600?
R1600 is single core Atom while R3600 is dual core Atom. Both are Nv9400M so video will be very good.
For pure Mythtv both will work OK - but with single core Atom expect rather slow (but fully acceptable) UI responsiveness.
UKenGB wrote:The R3700 is ION2 therefore not ideal.
I'm not sure is it ION2...
I think it is ION1 buth with Atom 2550 - not 535 (a bit faster, but no DMI)
it is for sure OK - but for equal price I'll go with R3600
UKenGB wrote:So the R3610 looks to be the best option? Dual core CPU, so more grunt, but still ION1 graphics. The best choice?
I my opinion yes.
UKenGB wrote:Would the above and also an ASUS EEEBox boot from the same MM2 image, or would they have to different? I just want a single network image so do I need to stick to the exact same box or could they all run from the same network files?
Having single image and full plug-and-play for any relevant HW is main goal for MM2.
Currently I have 7 different HW (ION1, ION2, AMD Brazos, AMD Kabini, AMD 8300 IGP, Intel 9400IGP, NUC) and all are working with single image, right out-of-box and full plug-and-play (5 of them don't have any config).
If it will not work single image and full plug-and-play - I'll extend MM2 to achieve this.

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Re: Rasberry PI 2 ?

Post by UKenGB » Thu Sep 17, 2015 9:44 am

I got the info mainly from:-

https://en.wikipedia.org/wiki/Acer_AspireRevo

That states the 3600 has the same CPU as 1600. Obviously could be wrong, are you sure the 3600 has dual core? In which case, what's the difference between the 3600 and the 3610?

I read that the 3700 is ION2 on the page of someone advertising to sell one. Since they're out pf production it's not so easy to get definitive info.

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Re: Rasberry PI 2 ?

Post by warpme » Thu Sep 17, 2015 10:07 am

UKenGB wrote:I got the info mainly from:-

https://en.wikipedia.org/wiki/Acer_AspireRevo

That states the 3600 has the same CPU as 1600. Obviously could be wrong, are you sure the 3600 has dual core? In which case, what's the difference between the 3600 and the 3610?
Indeed 1600 and 3600 seems bot to be single core. 3610 is dual core.

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