Windows10 IoT Enterprise eMMC sppeed problem

[Quinn_Liu]

Hi,

This topic talks about eMMC supporting HS200.https://community.nxp.com/t5/i-MX-Processors/eMMC-HS400-supporting-in-Windows10-IoT-Enterprise/m-p/1...,but I used the winstat tool in the Windows command line to test the eMMC sequential read speed, which is 45.47MB/s.

I measured the clock frequency of the eMMC through an oscilloscope and it was 52MHz. The eMMC seems to be working in SDR50 mode, which is consistent with the actual measured speed.

I am evaluating Windows 10 IoT Enterprise on i.MX8M Plus EVK, using W21H2-1-5-0-imx-windows-bsp. Please confirm whether V1.5.0 BSP + Win10 IoT supports eMMC HS200? If supported, how should I set it up?

[JorgeCas]

Hello,

I checked this with internal team, Win10 IoT supports eMMC HS200 but it seems that the speed depends of two factors:

- Memory used.

- Cleared/erased eMMC.

Here the results:

Using PassMark PerformanceTest.

I have noticed different score for Disk on another board with revision A. I have tested the revision B before. I have cleared the whole eMMC on advice from R&D. Installation of windows was much faster than before on that revision B. And the Disk score went from 300 to 730. It looks like there is no support of TRIM operation

On both boards are also different eMMC chips:

The score depends on performance of used eMMC. To compare score with another platform both should have use same eMMC and DDR too I would say. Otherwise, platform with faster component would have advantage over the slower one. But it should be obvious.

Best regards.

[Quinn_Liu]

Thanks for your reply, JorgeCas,

The eMMC on the IMX8MPLUSLPD4-CPU board I tested is SDINBDG4-32G, and the results I tested using PerformanceTest are as follows:

I have two questions:

1. The sequential read/write speed of SDINBDG4-32G in HS200 mode is 170/130 MB/s,

but the actual tested sequential read speed is only 43MB/s，why is it so much slower?

2. In HS200 mode, the eMMC clock should be 200MHz, but the frequency of the eMMC clock signal I tested is 52MHz? If it is eMMC HS200 mode, why is the clock not 200MHz?

[JorgeCas]

Hello,

Got it, thank you for the information.

For that I have understood HS200 mode is used by default.

Did you check with erased eMMC? According to the source code, HS200 is supported.

Best regards.

[Quinn_Liu]

Thanks JorgeCas,

eMMC is the only disk in the system, and Windows 10 is installed on it. I don't know how to erase eMMC in Windows. Should I erase the entire eMMC in U-Boot, then reinstall Windows 10, and then test it again?

If it is confirmed that HS200 is supported, I want to first figure out why the eMMC clock is not 200 MHz. I will try to debug the driver to verify whether the eMMC is really working in HS200 mode.

Best regards.