Werner

The interior is 10.5cm wide and 16cm high and 15.5 deep and a commercial ssd disk has a dimension of 10cm x 7cm x 0.6cm with case.
Create a new backplane with 4 x Jmb575 5 Sata ports spaced 1cm each you can plug 20 SDD (up to 80 TB = 20x 4TB) on the Helios64 and put your cache on M.2 Port Sata1 ,
and waiting for new SoC 4-8 line PCIe v.3 (RK3399 have 4 line v2.1) .
 
 

Shared lines are not uncommon even on x86 mainboards. For example: https://www.asrock.com/mb/intel/fatal1ty z97 killer/#Specification
Take note at Storage and Slots sections:
That is to mention as addition to @tommitytom.
You can try to sell it in forums. I already noticed a few people who did this successfully here. However if I were a potential buyer I'd consider a person with such an attitude not necessarily trustworthy

@Joãobt If you're going to follow @SteeMan suggestion, please report here your experience!

https://man7.org/linux/man-pages/man7/lvmcache.7.html
https://linuxhint.com/configuring-zfs-cache/
Here you go... use 4 HDDs and an SSD cache.
Or sell your unit, quite a lot of people wanted to buy one and couldn't in time.
OR, Frankenstein your unit and add in port multipliers to original SATA ports. Can add up to 20 HDDs to the 4 original SATA ports, and up to 5 SSDs to the remaining 1 original SATA port. The hardware controller specs say that it supports port multipliers, not sure about Armbian kernel, might have to modify.
 
Btw, you can take a look at the new version of Odroid H2+ with port multipliers (up to 10 SATA disks, + PCI-e Nvme) if you are into more tinkering. Also you get two 2.5G network ports instead of one. Hardkernel team has a blog post about its setup and benchmarks. https://wiki.odroid.com/odroid-h2/application_note/10_sata_drives
I am planning to expand my network infra with the H2+ soon. You can even plug a $45 4 port 2.5g switch into the Nvme slot now. I'm going crazy about this unit. If only it didn't have a shintel (r/AyyMD) cpu in.
 
Anyhow-
Just doing a bit of research shows that this was not a 'decision' made by Kobol, not exactly. There are just two reliable PCI-e to SATA controllers I could find that support multiple SATA ports(+4), with the limitation of RK3399 which has 4 PCI-e lanes. It would be a different story if RK had 8 lanes, but that is another can of worms that includes cpu arch, form factor, etc. Not gonna open that can while I'm barely qualified to open this one.
 
What we have here in Helios64 is JMB585, and then the other option was Marvel 88SE9215. Marvel only supports 4 ports, while JMB supports 5. There are no controllers that work reliably with 4 PCI-e 2.1 lanes and have more than 5 ports that I could find.
There is the quite new Asmedia ASM1166 which actually supports 6 ports, but that was probably not available during design of Helios64 as it is quite new. Not only that, there is a weird thread about its log output on Unraid forums.
 
At the end, this '5 ports only' was not exactly a decision for Kobol. But a rather uninformed decision made by you. You don't see people here complaining about this. You are the second one who even mentioned it, and the only one who is complaining so far with CAPS no less. Which means that the specs were clear to pretty much everyone that this was the case.
 
My suggestion is to replace one of the drives with a Samsung 860 pro, make it a SLOG/L2ARC, or in my case a LVM cache (write back mode, make sure you have a proper UPS, or the battery in the unit is connected properly) and call it a day. SATA port is faster than the 2.5G ethernet or the USB DAS mode anyhow so your cache SSD will mostly perform ok.

Shared lines are not uncommon even on x86 mainboards. For example: https://www.asrock.com/mb/intel/fatal1ty z97 killer/#Specification
Take note at Storage and Slots sections:
That is to mention as addition to @tommitytom.
You can try to sell it in forums. I already noticed a few people who did this successfully here. However if I were a potential buyer I'd consider a person with such an attitude not necessarily trustworthy

Hello! We have sent second version of patches for A3720 which should make 1 GHz mode finally stable:
https://lore.kernel.org/linux-arm-kernel/20210114124032.12765-1-pali@kernel.org/

Seems like the mistake is yours.  It's made pretty clear that the port is shared (it's even mentioned twice on the front page of kobol.io), it's not exactly a secret.

I would have loved to have the PBP. But it's a bit too expensive.
I've got my self made SBC "laptops". Either my first with a 7" 1024x600 display and Odroid C2 or RPi2b to save energy. All together -1A 5V.
And my 13.3" 1080p display either with M4V2 or Khadas VIM3. The display alone is 1.2A. I then clock my RK3399 to all cores 1Ghz for watching movies or internet. Uses less than 1A then. Still powerful enough.
Also got speakers in my display. So having this already I didn't see the sense in buying the PBP. Too bad they don't want to work with me. I'd love to have reviewed the PBP, the PinePhone, PineCube... 
I was the first to have a video about all those products since I filmed their stand at FOSDEM in 2019.
I now ordered a 60 000mAh power bank. I'll be able to use it for a week without charging. And it can charge with quickcharge. So in a rather short time I'll be able to charge it enough to last a long time. I can't wait for the lockdowns to be done so I can travel again. It's awesome to be able to use my desktop PC in my tent on solar power. 
Here a picture of my first box almost 5 years ago now. Doesn't look as good as PBP. But functions as I need it. 

I've got the NVMe hat on the way. I asked the people of Firefly. I only needed to pay for the hat, so I'm happy. The extra $30 for shipping was a bit too much for me. It's more than the device is worth. 
I don't know if I mentioned it already. I replaced the thick thermal pad with copper shims. It doesn't overheat anymore. I'll show it in my review video. I needed 2 copper shims on top of each other to reach the height of the thermal pad. With copper shims of double the height would probably perform a bit better.

Now the case does get very hot when used maxed out.
The CPU used to go over 85C and start throttling. Now maximum temperature is 79C and no throttling. Tho this is with 1.5Ghz/2Ghz overclock. With default clocks it didn't overheat.

Mine is 000048.

Is it just me, or did we have the exact same question a few weeks/month ago already?
 
EDIT: Found it! 
 
 
 

Since when its Armbian problem if your computer is infected by malware?

I haven't build Armbian for some time now, I'm just the guy who works on upstream U-Boot and Linux support for H616. I build all components separately and then manually put them together.

To get rid of all the tails that are now on your SD card, I recommend doing a clean check. Download the image from the link, unzip it and burn it to the SD card. Do not change anything on the SD card, connect to the device and check the launch.
 
https://users.armbian.com/balbes150/firefly_station_p1/
 
Model Fyrefly Station P1 = ROC-RK3399-pc-plus + eMMC module.

You can also check all the certification and conformity document for the PSU we provide with Helios64 : https://wiki.kobol.io/helios64/docs/#psu
 
We have designed Helios64 with safety and protection in mind... no shortcut.

You cannot. Happens very rarely but sometimes electronics in general can end up in magic smoke or even worse.
 
Best you can do is to look ahead and think about what would happen IF. Are flammable objects close by? Does the device lie on a wooden table? Are other devices close by that radiate heat and cause the concerned devices to heat up additionally?
How is your local public power supply? Do voltage spikes occur often? If so think about installing devices in the building connection that prevents such spikes from hitting your stuff. Kind a lightning conductor but way more sensitive against voltage above rated.
 
Try to look for more general information about fire hazard prevention. Maybe ask your local firefighter station.

Good news.
SATA works on mainline focal 5.10.6.
Also my 5Ghz wifi dongle works out of the box. I've got everything I could want. After that ordeal I'm so happy to have things working as should

There was actually an attempt to bring Armbian and Kali together and release it as images for SBCs. However the project is not very active. I guess they underestimated the effort needed to put in for maintenance
https://github.com/GoVanguard/karmbian

I'll continue to help with PBP..   As you all are familiar my work usually comes in bursts..  But yeah i'd like to build kind of a specific community up for it.. almost wonder if its worth a subforum under RK3399 or osmething.

I'm getting a PBP bare motherboard that i can use for the bare metal testing of liek uboot etc... and @Rich Neesehas a PBP coming in the mail
 

Sorry, my USB-C to DP/HDMI converter is broken, and I have no plans to make room in my budget for a new one, at least for now. So I cannot debug or fix this problem.
 
TBH, I am very surprised there is people using the Helios64 as a desktop device, I always considered it a NAS

Here is fixed v2 version: https://github.com/jernejsk/u-boot/commits/h616-v2
 
Note - it's not finished yet, so it will still change (force pushes).

There was actually an attempt to bring Armbian and Kali together and release it as images for SBCs. However the project is not very active. I guess they underestimated the effort needed to put in for maintenance
https://github.com/GoVanguard/karmbian

We will have some spare stock to sell soon.
Yes we ship to China.
 
As for the next batch we will announce our plan soon.

If it was a cheaper board I'd do that. This is one of the most expensive I've bought. PSU is also a 15V 60W brick. Adds to the cost.
I rather save my money to buy an Odroid Go Super next month. I never wanted a handheld so much, except when the Gameboy came out maybe.
HC4 also suddenly became a gaming rig with 500GB of retro games on HDD. Too many games, I can't find the ones I want since thousands to browse thru.

I also got my Odroid HC4. Doing my first tests. USB seems very buggy with the Ubuntu Mate 20.04 from Odroid.
This seems better with Armbian focal legacy desktop. Tho there no sata is found, while that does work with the Odroid HC4 Mate image.
I'll try a lot more images to see if/what difference there is.
Haven't checked any mainline yet.

It does seem to have performance issue's when overclocked(2Ghz/2.1Ghz). It sometimes performs worse than with default clocks. Weird.
I'm a bit surprised about how good it is for gaming.
I like it a lot, but it did cost me a lot. Tho also bit my own fault.
I first bought it from AmeriDroid. It was stuck in transit for a +month. So I got my money back and bought another at a Belgian seller. A lot more expensive. A day after I got my HC4 from the Belgian seller the one from AmeriDroid arrived. If only I had waited a few more days I'd have saved about 40euro. Buying from Hardkernel would have been even more cheap I'd guess.
I may send it back to AmeriDroid without fees. Luckily. I really wanted a HC4, but 2 is too much