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LattePanada Alpha : eGPU + SSD

Posted: Tue Nov 06, 2018 10:56 pm
by aromap
Hi everyone,

From what I've understood of the m2 slots on the Alpha board, it is impossible to have an eGPU and a NVMe SSD at the same time.
Only the m2 M slot can handle a NVMe SSD or an eGPU (with a pcie adapter).

Is there a solution to use the m2 e-key slot for storage ? with a pcie adapter maybe ?

I'm really new to this.

Have a nice week.

Re: LattePanada Alpha : eGPU + SSD

Posted: Wed Nov 07, 2018 12:41 pm
by aromap

Re: LattePanada Alpha : eGPU + SSD

Posted: Wed Nov 07, 2018 1:31 pm
by ccs_hello
(Over that link) there is an incorrect statement about PCIe bus sharing.

Actually, correct statement should be Key-M and key-A+E slots do not share PCIe bus.

CPU m3-7Y30 is Kaby Lake "Y" 7th gen CORE M processor 4.5W TDP
It supports max of 10 PCIe lanes, on board, 6 available/used:
PCIe root-port #3: used by Intel WiFi (+ BT) module
PCIe root-port #4: Gigabit Ethernet RTL8111E
PCIe root-port #5 (and 6, 7, 8): M.2 M-Key (max 4 lanes and can do x4),
PCIe root-port #9 (and 10): M.2 E-Key (max 2 lanes and can do x2)
20181107_082.jpg
20181107_082.jpg (140.45 KiB) Viewed 3466 times

Re: LattePanada Alpha : eGPU + SSD

Posted: Wed Nov 07, 2018 1:47 pm
by ccs_hello
re: Is there a solution to use the m2 e-key slot for storage ? with a pcie adapter maybe ?

Yes, several ugly solutions. The approach is to "bring out key-E slot's PCIex1 or PCIex2 bus".
To do the x2 method, some hardcore DIY is required.

Once the PCIe bus is exposed, one can use NVMe SSD (but now downgraded to PCIe x1 bus bandwidth) or use a SATA PCIe card to use a regular SATA drive.
<-- This paragraph has several approaches, regular sized PCIe, M.2 form factor, etc.

There is a completely different approach, direct-access to SATA signal, a hardcore DIY method.

As LattePanda Alpha 800 (about to be) released, I believe this topic will be brought up over and over.
(Sadly, that key-E slot was not designed originally as a key-B slot instead;
or a design revision to bring out the SATA connector...)

ccs_hello

Re: LattePanada Alpha : eGPU + SSD

Posted: Wed Nov 07, 2018 3:30 pm
by aromap
thanks for the information :)

Re: LattePanada Alpha : eGPU + SSD

Posted: Tue Apr 02, 2019 11:20 pm
by Project-SBC
aromap wrote:
Tue Nov 06, 2018 10:56 pm
Hi everyone,

From what I've understood of the m2 slots on the Alpha board, it is impossible to have an eGPU and a NVMe SSD at the same time.
Only the m2 M slot can handle a NVMe SSD or an eGPU (with a pcie adapter).

Is there a solution to use the m2 e-key slot for storage ? with a pcie adapter maybe ?

I'm really new to this.

Have a nice week.
I may have found an adapter that will work. Check out my video on it here. I’ll do testing shortly via crystal disk benchmark.

https://youtu.be/UUT99pgk_Bs

Re: LattePanada Alpha : eGPU + SSD

Posted: Wed Apr 03, 2019 3:39 am
by ccs_hello
Unless that vendor made a design change, I believe that key-E to key-M adapter is only exposing PCIe 1x bus.
(I had communicated with the manufacturer about 2 months ago.)

BTW, AFAIK, there is no one making a key-E PCIe 2x (2-lane PCIe bus) adapter.

Re: LattePanada Alpha : eGPU + SSD

Posted: Wed Apr 03, 2019 4:14 pm
by Project-SBC
ccs_hello wrote:
Wed Apr 03, 2019 3:39 am
Unless that vendor made a design change, I believe that key-E to key-M adapter is only exposing PCIe 1x bus.
(I had communicated with the manufacturer about 2 months ago.)

BTW, AFAIK, there is no one making a key-E PCIe 2x (2-lane PCIe bus) adapter.
Css_hello, you are right, it does look like it is 1 lane PCIe. The E key was capping out around the 1 PCIe lane theoretical limit (~900 MB/s). Performance wise (via crystal disk mark) shows a 50% loss from the M key to E key with the Samsung 970 evo for large transfers only. I will do some larger test files to see what the true gap is between the M key and E key.

On the low queue depth and file transfer size, the drives performed fairly similar. You MIGHT see some larger differences if you used one of the intel optane SSD at low queue depth rates. In real life scenarios, there isn’t much user feel difference. Boot times between the two keys with the Samsung as boot drive had at most a 2 second delay on the E key. The most important thing in my opinion is that the data transfer is through a PCIe lane and therefore there is the lowest response time.

Not letting perfect be the enemy of good, this is a perfectable acceptable and viable solution to have both a SSD and eGPU for the LattePanda Alpha. I will be doing exactly this in a couple days.

I will also post a video with the boot ups and benchmarks in a day or two.

Re: LattePanada Alpha : eGPU + SSD

Posted: Sat Apr 06, 2019 7:53 pm
by Project-SBC
Here is my review of the adapter including benchmarks and boot times

https://www.youtube.com/watch?v=owIFL40NQIs

Re: LattePanada Alpha : eGPU + SSD

Posted: Sun Oct 13, 2019 11:08 pm
by TrickyAamir
Here i installed a NVME SSD and a external graphics card (eGPU) on a Lattepanda Alpha :mrgreen:

Used M Key slot for SSD and E Key slot for eGPU,

Check Tutorial: https://www.youtube.com/watch?v=OGCLXPDPtfk