Olimex Support Forum

Others => TERES DIY Laptop => Topic started by: farukhkhan21 on February 18, 2018, 12:52:33 AM

Title: Some questions and suggestions
Post by: farukhkhan21 on February 18, 2018, 12:52:33 AM
First of all, really nice open source project. I appreciate all the efforts behind this project. So, some of my initial questions if you guys can answer:

1. Why you guys are limiting yourself to Allwinner A64 processor and only 2GB DDR3 memory? Also, why not go for M.2 SSD instead of the eMMC to reduce the overall latency of the system and increase the disk I/O? Ever thought about RockChip RK3399? with ARM Cortex A72 + A53 in big.LITTLE configuration? And by the way the 64bit CPU's can support more than 2GB of RAM. So, why not a 4GB and 8GB DDR3 Dual Channel variations?

2. Why no USB 3.0/3.1 and Gigabit ethernet? Or these modules still in development? And how about WiFi AC and BLE 4.2 or 5?

3. As a kit based or modular project why not multiple chasis and lcd sizes? 10.1", 11.6", 12.3", 13.3", 15" etc.

Thanks.
Title: Re: Some questions and suggestions
Post by: starkwether on February 18, 2018, 04:16:51 AM
Hello, I don't speak for and am not affiliated with Olimex in any way but maybe I can answer some of your questions and share my viewpoint:

Check out   the wiki page for the TERES processer, the Allwinner A64  (https://linux-sunxi.org/A64). The A64 is 64 bit, correct, but does not support any more than 3 Gbs of RAM.

Yes, the A64 is not super powerful but the excellent thing about it is that it isn't vulnerable to the  Specre and Meltdown exploits  (https://meltdownattack.com/) which is a pretty big deal if you care about security or privacy.

Here's ARM's statement on what CPUs were affected.  (https://developer.arm.com/support/security-update)  Looks like the RockChip RK3399 uses the A53 just like the TERES but also unfortunately the A72 which has issues. Techarp also has a  list of all CPUs with Spectre/Meltdown issues.  (https://www.techarp.com/guides/complete-meltdown-spectre-cpu-list/)

Free and open drivers for Linux rely on the manufacturer releasing them or reverse engineering. In the case of Wireless AC, the community has been flat out denied driver source code. See this  Reddit post  (https://www.reddit.com/r/linux/comments/7vj621/why_no_opensource_80211ac_wifi_adapters/) for info.

Chassis size choices would be great but that all that custom injection molding by a third party sounds difficult and expensive. 3D print our own? I had a thought to build a TERES into a mech keyboard housing maybe...

I'm happy with my TERES as I feel it's one of the most trustworthy and potentially secure computing platforms available now. I only wish it  had ECC memory  (https://en.wikipedia.org/wiki/ECC_memory)  :D
Title: Re: Some questions and suggestions
Post by: farukhkhan21 on February 18, 2018, 11:32:48 PM
Hi there,

Thanks for your reply. I wasn't aware of the 3GB max ram support in the A64 processor. So, I think they should totally max this out to 3GB on the Teres main board. And I was aware of the A72 spectre and meltdown issue but linux arm kernel has already good patches for this. Anyways just to be totally secure, I agree that A64 with Cortex A53 is the best bet. But really the RAM should be upgraded to the processor's max capability of 3GB @ DDR1333 with NAND Flash controller and 64-bit ECC.

To 3D print our own teres should provide a baseline design for the 3D model of the laptop and also the suggested materials for 3D printing. And a variety of LCD display sizes which supports the teres main board. Maybe also some expensive LCD IPS panels with 1080p and 1440p resolutions because the A64 can do 4K/2K at a reasonable fps. And building a teres into mechanical keyboard enclosure seems really cool. But I think the HDMI needs to be exposed on the main board for that.

I understand now why no wireless ac. By the way is there any way possible teres stating the source and prices for individual components used in all the teres boards including the main board? Suppose from where to source Allwinner A64 and what is the price of the individual processor. From where to source samsung RAM and their prices. etc. This way we can build the open source board at our end and just source the parts we need.

Thanks.
Title: Re: Some questions and suggestions
Post by: starkwether on February 19, 2018, 08:15:41 PM
Glad to help.

Careful though, Meltdown and Spectre are related but different issues; Meltdown has hopefully been mitigated for many CPUs but Spectre is not a quick band-aid. It's going to be a while until anyone is sure they're safe from Spectre unless they use a processors without Branch Prediction. Spectre even effects things like Nvidia GPUs.

Haha, ECC is good stuff but it's typically found in servers and not supported by the A64. I wish, because there's a lot of ionizing radiation where I live ;D but more importantly ECC can make  Row Hammer  (https://en.wikipedia.org/wiki/Row_hammer) harder, if not actually stop it.

If you want to make your own TERES board, that is well beyond my skill level but the place to start would be grabbing the TERES KiCAD files and understanding those. I'd guess there's a BOM in there?

For parts like the A64, Samsung DRAM, Atmels, etc, I think the first place to check would be the usual online stores such as  digikey  (https://www.digikey.com/) or  mouser  (https://www.mouser.com/).
Title: Re: Some questions and suggestions
Post by: LubOlimex on February 20, 2018, 09:56:46 AM
Hey,

About your questions, farukhkhan21:

1. We are working on new designs with different processors compatible with the Teres-I. This was just the first main board that we have completed! Any ideas and suggestions are welcome! Of course, faster chips and more RAM are always a good idea!

2. The A64 chip has no native USB 3.0/3.1 support. The Ethernet jack is too big for our plastic case, and also the Gigabit Ethernet and the LCD output are multiplexed, e.g. can't work simultaneously.

3. Good idea! No one knows what the future can hold. Yet, we usually have a major problem when it comes to plastic cases! We had problem finding this one, can't imagine if we have to go through a range of sizes and displays. Our ordeal with cases is also detailed at the "PLASTICS" part in this blog post: https://olimex.wordpress.com/2018/01/19/teres-i-diy-open-source-hardware-modular-hackers-laptop-update/

P.S. I won't lie, the fact that the A64 turned out immune to Spectre and Meltdown (since the A53 micro-architecture doesn't perform out-of-order execution) made me really happy.
Title: Re: Some questions and suggestions
Post by: farukhkhan21 on February 20, 2018, 12:45:40 PM
Thanks for all the replies guys. @LubOlimex please open source the new board designs you guys are working on if you haven't. Then in the github people will be able to suggest modern high performance and compatible parts. Suppose, which processor to pick, which RAM, does the processor supports this or that etc. Maybe I will also be able to contribute on the circuit designs and some kernel stuffs.
Title: Re: Some questions and suggestions
Post by: farukhkhan21 on February 20, 2018, 12:51:28 PM
And by the way why not make the LCD panel modular also? How about using a LCD controller on the panel and use a HDMI input from the Teres main board? Then it will also allow users to put their own preferred main boards inside the teres chasis and connect to the LCD using HDMI from their main board.