PC not booting at all with EXPO on & some issues

[InfiniteNoise]

So I'm trying to sort out things on a relative's computer with few issues, the components that are potentially problematic & the issues are,

Components,
- Ryzen 7900
- MSI B650i Edge board (with latest BIOS released on 15/8)
- Corsair Vengeance DDR5 RAM, 32GB (2x 16GB), 6000MHz CL36, AMD EXPO Compatible
(for the rest of the system, Corsair SF750 PSU, Radeon RX 6700)

Issues,
- won't POST/boot at all with EXPO enabled, or with it off + memory clocks higher than stock (4800MHz)
- any curve optimizer settings (even very minor negative/positive) eventually results the PC not booting after few restarts/shutdowns

When these issues occurs, the only way I can get the PC to boot again is to clear CMOS. If I leave everything on stock, it runs wonderfully without any issues, stable when stress tested, it's just that any adjustments to the CPU or RAM results in the PC not booting, and on the rare occasions it manages to get past POST, it just hangs.

CO isn't the issue, but not being able to run higher clocks for the RAM got me stumped.

Tried reseating everything and re-flashing BIOS, didn't help, I can't tell if it's one or more of those components that's a lemon (when not running at stock).

Our system is pretty much identical, except mine has 7800X3D, and their RAM in mine runs at EXPO 6000 Mhz fine, so I guess the RAM is fine.

What am I missing?

 

[Tetras]

When you enable EXPO, is it setting the voltages correctly? That would be the first thing I'd check.

 

[InfiniteNoise]

When EXPO is on, the DRAM voltage is set to 1.350v, which seems about right? I tried setting it to 5200mhz non-EXPO with 1.350v (up from 1.1v on stock), booted but CPU runs a bit slower.

Everything at stock (4800MHz, DRAM voltage at 1.1v), the CPU scores 25500~ in CB R23 mulitcore test, which is actually a bit higher than normal.

But with RAM adjusted to 5200Mhz with voltage at 1.35v, CPU scores 24100~ in CB R23, which is about right for the CPU on stock, but that's lower than above when everything is on stock.

Looking at the CPU clock speeds when running CB R23 multicore test, 4.6GHz all core when everything is on stock, 4.4GHz all core with RAM at 5200MHz.

Not ideal but I'm getting there I guess.

Edit: also to add that I'm aware about the memory training and long boot time issue with EXPO, but even after waiting 30+ mins on couple of occasions for it to finish training with EXPO enabled, nothing happens.

 

[Jamin280672]

When EXPO is on, the DRAM voltage is set to 1.350v, which seems about right? I tried setting it to 5200mhz non-EXPO with 1.350v (up from 1.1v on stock), booted but CPU runs a bit slower.

Everything at stock (4800MHz, DRAM voltage at 1.1v), the CPU scores 25500~ in CB R23 mulitcore test, which is actually a bit higher than normal.

But with RAM adjusted to 5200Mhz with voltage at 1.35v, CPU scores 24100~ in CB R23, which is about right for the CPU on stock, but that's lower than above when everything is on stock.

Looking at the CPU clock speeds when running CB R23 multicore test, 4.6GHz all core when everything is on stock, 4.4GHz all core with RAM at 5200MHz.

Not ideal but I'm getting there I guess.

Edit: also to add that I'm aware about the memory training and long boot time issue with EXPO, but even after waiting 30+ mins on couple of occasions for it to finish training with EXPO enabled, nothing happens,

Try giving the ram a little more juice, manually set the ram voltage to 1.37v after enabling expo, its not going to hurt it, ive found a lot of boards dont give the full 1.35v, some of them just drop it down to 1.34v, and the 0.01v makes the world of difference,......cant remember if MSI is one of them, but gigabyte definitely is, you can double check once in windows using HWinfo.

I wouldnt bother messing with Curve optimizer yet, you'll just be making everything more difficult for yourself basically reducing the voltage on cores, my 7900 is a nightmare setting curve optimizer up, ive actually disabled it completely for now since going direct die as the CPU is giving me more at lower temps, so ive gone back to playing with RAM timings, it will be a week or 2 before I start working on CO again, but on my 7900 some cores were -3, others -5, and others yet were -20, it was weeks of constant overnight testing and testing during the day whilst I was at work, so theres a long way to go.

 

[InfiniteNoise]

I'll have to give that a go in a moment, but if that doesn't help and it results in the PC still not booting, I'll just not bother with overclocking the memory speed and instead just tighten the timings a bit.

Yeah, won't bother with CO either, even on stock it performs decently, I'm surprised with how well it runs compared to 7900X with just almost the 1/3 the TDP.

Looks like EXPO is just annoying to deal with based on what I've seen.

 

[Jamin280672]

I'll have to give that a go in a moment, but if that doesn't help and it results in the PC still not booting, I'll just not bother with overclocking the memory speed and instead just tighten the timings a bit.

Yeah, won't bother with CO either, even on stock it performs decently, I'm surprised with how well it runs compared to 7900X with just almost the 1/3 the TDP.

Looks like EXPO is just annoying to deal with based on what I've seen.

Just one other thing, are you sure its an EXPO kit not a XMP kit ?

Nothing wrong with that, mine is an Intel XMP kit, but wont run EXPO, ive had to set everything up manually, all timings and voltages for everything, mem controller, soc, mem itself, etc etc.

Wait till you really get to playing with it, mine is boosting to 5.6ghz on a regular basis, which I think the 7900X boosts to at stock ? they are great chips, I was torn between a 7900 and 7800X3D, but as I dont game much, I came to the conclusion there wasnt any point getting the 7800X3D, at didnt want the 170w counter part.

 

[InfiniteNoise]

As mentioned in the initial post, the kit is Corsair Vengeance DDR5 RAM, 32GB (2x 16GB), 6000MHz CL36, AMD EXPO Compatible.

Though that same kit worked fine in my system with EXPO enabled, I'm starting to think it's the motherboard that's the issue.

 

[Tetras]

Though that same kit worked fine in my system with EXPO enabled, I'm starting to think it's the motherboard that's the issue.

Looks like EXPO is just annoying to deal with based on what I've seen.

DDR5 does seem different to DDR4. With XMP3/EXPO the boards seem to change a lot more than just the dram frequency/voltage and are more unstable when only those two things are changed.

 

[Ziggystarduft]

On the ram issues, I'm running the same speed/spec kit on b650 Aorus Elite AX and I though the pc wasn't posting turns out it was just taking a long time to train on first boot.

When first setting expo the pc would look like a no post and fans would blast full speed, I found some advice saying DDR5 can take longer to train so I walked off and came back 5 minutes later with it booted no problem.

After that first training it boots quick and its been completely stable.

I've since made changes to the system and every time I reset the bios I see the exact same behaviour, set expo reboot wait a few minutes and boom it boots. When I actually timed it its about 2 minutes or so.

Don't know how long you've left it but might be worth a try.

 

[InfiniteNoise]

I'm aware, it just won't boot at all with EXPO enabled, I've waited 30+ mins, and since my last post here I've conducted some more tests, it's the motherboard that's the issue.

I put the CPU + RAM in my motherboard (same board, MSI B650i Edge, both on same BIOS version as well as similar settings), and they ran fine with CO + EXPO enabled without issues while they couldn't in the other board, and to rule anything else out, I tested the same CPU + RAM in another board that I borrowed (ASUS ROG Strix B650E-I) and they ran fine too.

The board is still in its return window so I'll ask them to return it and get a different board.

Update: new board arrived, EXPO works, just as I expected, the board is useless so it goes back.