Tesla MCU Index - ARM Tegra, Intel Atom, AMD Ryzen

[Krash]

A comparative index of the differences between MCU1, MCU2 and MCU3/MCUZ...

Sources and related threads:
AMD Ryzan speed comparison vs Intel Atom
https://teslamotorsclub.com/tmc/threads/new-model-y-performance-no-ryzen.258552/
https://insideevs.com/news/561232/amd-ryzen-affects-range-tesla/
https://teslanorth.com/2021/11/30/tesla-model-y-amd-ryzen-vs-model-3-with-intel-atom-chip-video/
https://teslatap.com/articles/autopilot-processors-and-hardware-mcu-hw-demystified/
https://videocardz.com/newz/tesla-c...n-ryzen-embedded-apu-and-discrete-navi-23-gpu
https://wccftech.com/amds-ryzen-cpu-reportedly-cuts-down-tesla-model-3s-driving-range/
https://www.cpu-world.com/Compare/231/Intel_Atom_x5_Z8350_vs_Intel_Atom_x7_E3950.html
https://www.intel.com/content/www/u...r-2m-cache-up-to-2-00-ghz/specifications.html

 

[t3sl4drvr]

To me the largest advantage of MCU3 over MCU2 seems to be that Tesla is more likely continues to supporting MCU3 for longer than they will support MCU2. This would include new software releases including features for MCU2, protecting software against regressions specific only to MCU2, keeping the software releases performing well on MCU2, and releasing any software updates at all to MCU2.

Tesla already has practically stopped supporting MCU1 that was still in new cars sold just four years ago. Today all those cars are out-of-warranty and Tesla does not seem to have any obligation of keeping those cars working properly. When exactly we can expect MCU2 support to become similar disaster compared to MCU1 is unknown. My guess would be 2026, when the last MCU2 cars are out-of-warranty.

I hope regulators will force manufacturers to commit to clear timelines when selling a car. Purchasing a new car today leaves it unclear how well - if at all a properly maintained car will work - in 10 years from the purchase date.

 

[t3sl4drvr]

I wish Tesla will make MCU3 upgrade available to MCU1 cars. That would give those cars a way longer life extension compared to an already out-of-date MCU2 upgrade.

 

[TMYB-C1]

Can one upgrade from MCU2 to MCU3?

 

[Krash]

Can one upgrade from MCU2 to MCU3?

Still waiting for the first person to try on the S/X. Getting the UI to run vertically on it may be harder that faking the liquid cooling. Also tricky that MCU3 has HWx integrated.

The 3/Y ought to be easier since none of those three problems exist, but Green says it still won’t happen mostly due to physical size and harness/power.

Size and power should come down in a theoretical MCU4, so maybe later.

 

[vcor]

Can one upgrade from MCU2 to MCU3?

Not currently, and likely not ever although a small possibility on the 3/Y. On the S/X there is nothing similar between MCU2 and MCU3 as far as wiring, connectors, placement, and more. MCU3 required liquid cooling, which is not available in the cabin for cars made for MCU1 or MCU2 with the S/X. Now for the 3/Y, there is perhaps some hope as MCU2 was water cooled and the physical placement hasn't changed. I don't know if the connectors changed or if other key electrical changes were made in the 3/Y when Tesla switched from MCU2 to MCU3 which would prevent a reasonable retrofit.

 

[EV bud]

I just had my MCU/whole touch screen replaced this week on our 2020 LR+ Model X. They have to address a few other things, but when I played with the touchscreen and map rendering, it was noticeably faster than the original MCU that came with the car (something I observed on delivery). The units are clearly MCU2, but curious if there are variations of MCU2 if MCU3 may not be supported on vertical screen S/X's?

 

[Krash]

…curious if there are variations of MCU2…

Interesting question. I’m sure there are minor revisions, but I suspect the specifications are identical.

Obviously you can’t put a Ryzen on an Atom board, but it would be interesting to see if the chipset that the MCU2 board uses supports any other CPUs. I assume some here are good enough to float a new BGA CPU on a rework station.

 

[EV bud]

I suspect they have a couple suppliers for certain chipsets and some just don't perform as well as others, but are "within spec". Have there been any known warranty replacements on vertical S/X vehicles with MCU3?

 

[Droschke]

Interesting question. I’m sure there are minor revisions, but I suspect the specifications are identical.

Wouldn't the part numbers be different then?

 

[Krash]

Wouldn't the part numbers be different then?

I’m pretty sure there is only one part number.

 

[Krash]

Anyone ever determine if the MCU3 modem is 5G capable?

 

[EV bud]

Looks like there may be a new part number for the MCU2? Unfortunately, the replacement didn’t fix my issue. Screen stills freezes, more debugging needed.

 

[jswifter]

Thanks for this @Krash. Is there any other source of model numbers? I'd like to search for a MCU3 on ebay, but 1637790 only brings up MCU-Z. And for instance when I search on ebay and look at pics, I can see lots of other model numbers like 1775000 or 1684435 or 1681271 which aren't listed in that table, and ideally I'd like to create a saved ebay search for a known-correct part number. (It's hard to see but I think the 1684435 is the part number of this one which is claimed to be an MCU3 one?)

 

[Krash]

Anyone else notice that T-Mobile is licensing part of its spectrum to Starlink so that it’s customers can use Starlink v2 satellite data in the future? Some debate about whether the spectrum is 5G or older PCS.

Hmmm.

5G in MCU3/MCUZ (speculated) plus a switch from AT&T to T-Mobile would mean instant Starlink in the future. Somebody at Tesla has to be thinking about this.

 

[PaulF2020]

As far as I can see, the only CPU upgrade on MCU you can do is upgrading to Pentium J4205, it has significantly higher turbo frequency on CPU and GPU. The only problem can be, Pentium does not support ECC memory when Atom does, I'm not sure what RAM is used on MCU2.

 

[Krash]

…the only CPU upgrade on MCU you can do is upgrading to Pentium J4205, …Pentium does not support ECC memory when Atom does…

Do you mean MCU1? Is the J4205 pinout identical?

Also, I know I typed the original list but I’m still shocked that the atom could support ECC, here it is.

 

[Krash]

MCU3/MCUZ originally listed for S/X had the GPU daughter card, but spy photos are already out of the new CPU GPU single PCB. Not sure if the components change.

We should probably also include the 3/Y Ryzen no dedicated GPU board that was released after this thread was started.

 

[PaulF2020]

Do you mean MCU1? Is the J4205 pinout identical?

Also, I know I typed the original list but I’m still shocked that the atom could support ECC, here it is.

No i mean to upgrade cpu in mcu2 to a faster one

 

[PaulF2020]

I think CPU/GPU board on MCU2 is also a daughterboard, I wonder if someone can make upgrades for it, shouldn't be too complicated to replicate PCB, component and fit more powerful CPU there, maybe even newer generation intel Atom. They an sell it for a nice premium since there will be no upgrade paths to MCU3.