If you don't mind me asking, what's the issue with Tegra 2?

Ask questions about DraStic or discuss compatibility issues here.
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JimBobIII
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Joined:Thu Aug 08, 2013 2:58 am
If you don't mind me asking, what's the issue with Tegra 2?

Post by JimBobIII » Thu Aug 08, 2013 3:31 am

After losing my Xperia Play a few months back, I finally purchased a 'new' phone, a Samsung Captivate Glide, on eBay earlier this week. I was excited to find out about DraStic's release and subsequently a bit disappointed at its lack of Tegra 2 support. Should I assume that the issue here is the Tegra 2's lack of NEON support (the biggest flaw I can think of, off the top of my head), or is there some other underlying issue? Should I also assume the likelihood of a fix or workaround is slim or zero? I don't really know if the Android version is being developed actively alongside the Pandora version or if it's more of a port.

I hope I'm not sounding rude or overly pessimistic; I'm really impressed by this project even if it'll be a few more years before I have use of it anyways. I'd put down the $8 if I still had a compatible device linked to my Google Play account, but I don't think it'll let me.

ChronoReverse
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Joined:Wed Aug 07, 2013 2:41 pm
Location:Vancouver

Re: If you don't mind me asking, what's the issue with Tegra

Post by ChronoReverse » Thu Aug 08, 2013 4:09 am

JimBobIII wrote:After losing my Xperia Play a few months back, I finally purchased a 'new' phone, a Samsung Captivate Glide, on eBay earlier this week. I was excited to find out about DraStic's release and subsequently a bit disappointed at its lack of Tegra 2 support. Should I assume that the issue here is the Tegra 2's lack of NEON support (the biggest flaw I can think of, off the top of my head), or is there some other underlying issue? Should I also assume the likelihood of a fix or workaround is slim or zero? I don't really know if the Android version is being developed actively alongside the Pandora version or if it's more of a port.

I hope I'm not sounding rude or overly pessimistic; I'm really impressed by this project even if it'll be a few more years before I have use of it anyways. I'd put down the $8 if I still had a compatible device linked to my Google Play account, but I don't think it'll let me.
Tegra 2 doesn't work because, as you suspected, it lacks NEON.

JimBobIII
Posts:9
Joined:Thu Aug 08, 2013 2:58 am

Re: If you don't mind me asking, what's the issue with Tegra

Post by JimBobIII » Thu Aug 08, 2013 5:49 am

Yeah, not surprising. I still have no idea what Nvidia was trying to do by releasing a multimedia-focused chipset without key multimedia support. I'm not really concerned as I still have my 3DS anyways, but I always enjoy being able to compress the number of devices I need/use even further, and I suspect I'll be replacing my phone again in a year or two anyways.

a41airport
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Joined:Fri Aug 09, 2013 2:37 am

Re: If you don't mind me asking, what's the issue with Tegra

Post by a41airport » Fri Aug 09, 2013 3:01 am

So, will it work with Tegra 2 in upcoming updates?
It would be prefect if the emulator work with Sony Tablet P.

JimBobIII
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Joined:Thu Aug 08, 2013 2:58 am

Re: If you don't mind me asking, what's the issue with Tegra

Post by JimBobIII » Fri Aug 09, 2013 7:39 am

There's pretty much no chance unfortunately. From what I've seen around the web, DraStic relies pretty heavily on NEON (which, to oversimplify things, is ARM's main media processing engine/instruction set for ARMv7+). This is the reason Tegra 2, Intel Atom, and MIPS devices can't run it - Intel Atom is a non-ARM architecture that can emulate or interpret ARM code, but apparently can't or doesn't handle NEON instructions, MIPS is a non-ARM architecture, and despite using ARM Cortex-A9 cores (which are fully capable of supporting NEON, but it's apparently an optional feature), Nvidia decided to release a multimedia/gaming-oriented chipset without proper NEON support as the Tegra 2.

Getting the emulator to work without using NEON would require a rewrite of every part of the emulator that uses NEON, which is fairly counter-intuitive - 90% or more of the devices that have compatible specs have NEON-capable processors, and there's no reason to do it from a performance standpoint either.

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