Boot Loop And CMOS Error After Enabling XMP In BIOS (PO3-640)

I upgraded my computer a year or two ago with extra RAM. The RAM was rated for 3600Mhz, but ran at 2133MHz because the original RAM that came with the computer only ran at that speed. Today I upgraded the computer again by replacing the original RAM with two more sticks of the same RAM as the extra RAM I added a while ago. When I got into Windows (with no issues) the RAM speed was only 2133MHz. I looked on the forum and it said that I needed to enable XMP in the BIOS for it to run at the motherboard limit of 3200MHz.

I went ahead and did that, but then the computer entered a boot loop. I'd turn it on, the screen would be blank for twenty seconds, and then the computer would turn itself off. It would restart itself and the process would continue. After six or so attempts I put it out of its misery by holding the power button to turn it off. I waited about twenty seconds and turned it back on. This time it re-entered the boot loop but managed to reach the startup screen on the third go. I wanted to enter the BIOS so I pressed Delete, and I got a screen that said there had been a CMOS error and the settings had all been reset. Continuing into the BIOS setup, I found that it really had reset all the settings.

I didn't touch the CMOS battery and it didn't shout about it before. After leaving the BIOS Windows booted normally. I had already done a RAM test before enabling XMP - no issues, so I don't know why it caused an issue.

Something that I did note was that before I changed the RAM, the memory utility in the command prompt listed the RAM speeds as 2133/3200/2133/3200, with the faster ones being the extra RAM I fitted a while ago. When I installed the new RAM, they all said 2133 for seemingly no reason. The BIOS is on R01-B1, the latest version.

Finally, the RAM is of two (identical) types. They're Corsair Vengeance RGB sticks, two of which have the product code CMG16GX4M2D3600C18 and the other two CMG8GX4M1D3600C18. The former are the new ones. The only difference to my knowledge between them is that the new RAM is from a set of two, whilst the others are two separately bought 8GB sticks.

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Puraw

https://community.acer.com/en/discussion/722678/boot-loop-and-cmos-error-after-enabling-xmp-in-bios-po3-640

I am listing a few threads on upgrading RAM for this desktop:
Predator Orion 3000 PO3-640 – Memory upgrade — Acer Community
Acer Predator Orion 3000 po3-640 64gb Ram Upgrade — Acer Community
It seems that some users have reported issues with Corsair Vengeance modules not booting or running at their advertised speeds in the Acer Predator Orion 3000 PO3-640 desktop.

StevenGen

https://community.acer.com/en/discussion/722678/boot-loop-and-cmos-error-after-enabling-xmp-in-bios-po3-640

All the ram in your PO3-640 desktop should be DDR4-3200MT/s CL22 type and the DIMM slots should be populated @ 4x 16GB modules to achieve the 64GB max total for this desktop, look at the PO3-640 Acer service guide chart below. Also make sure that the PO3-640 bios is at its last version R01-B1 for best ram performance.

I suggest that you buy the exact ram that Crucial suggests as its a Micron ram and it works, and follow the Crucial Acer Predator PO3-640 RAM & SSD Upgrades guide and if you want to use the XMP switch in bios and to turn it to ON, I suggest that you buy/fit the Crucial Pro DDR4-3200MT/s CL 22 type ram for best performance results, as that can be overclocked and then and when the XMP switch is turned ON in bios, the ram speed will be overclocked to whatever Acer has appropriately set the max ram speed at, which should be above 3200MT/s.

The reasons why you desktop is in a boot loop is because you have mixed ram speeds and incompatible ram that does not work with this desktop like the DDR4-3600MT/s type modules, as that is what happens if you mix ram of different speeds, it gets down clocked irrespectively to the lowest 2133MT/s speeds. For precise ram speeds always look at the windows OS Task Manager > Memory as the PO3-640 should be running at 3200MT/s plus whatever the XMP switch increased the ram speed above 3200MT/s speed to. let us know as it would be interesting to know what the XMP switch in bios increases the ram speed to?

The only compatible ram that you should fit to the PO3-640 desktop is the DDR4-3200MT/s CL22 or XMP ram that works at 3200MT/s and above speeds with the XMP switch in bios turned on. Buy the Crucial Pro type ram, as this ram will be overclocked to a higher ram speed that Acer has the XMP setting set to. I suggest that you follow the Crucial RAM guise for the PO3-640 and the Acer PO3-640 ram DIMM slots population table below for the ultimate ram performance for your PO3-640.

Aver PO3-640 RAM DIMM 1 to 4 population guide:

Just as a guide this is the ram that Acer has tested and recommends for the PO3-640 desktop, so you can follow this guide too.

If this answers your question and solved your query please "Click on Yes" or "Click on Like" if you find my answer useful👍

Doomotron

The advertised speed for each of the sticks of RAM in the computer is 3600Mhz. I was already aware that I wouldn't be able to get up to that speed. Just to make it completely clear, this is the series of changes I made to the RAM since getting the computer:

Initial RAM: 2x Kingston 8GB sticks, fitted from the factory.
One extra RAM stick added, Corsair Vengeance RGB RS 8GB, C18, 3600Mhz.
Second duplicate of the above added. Now 32GB total. The speed listed is 2133Mhz for the Kingston sticks and 3200 for the Corsair sticks, although I assume it was all running at the former speed.
Replaced both Kingston sticks with Corsair Vengeance RGB RS 8GB, from a set of two. Identical stats to the other Corsair Vengeance sticks. Works fine, but all listed at 2133Mhz.
Enabled XMP in the BIOS. Boot loop.
After power-cycling, the BIOS shows a CMOS error and all settings are reset.
Launch into Windows (now with XMP disabled), works fine.

The issue only starts when XMP is enabled. With it disabled, the overall speed in the task manager is 2133MT/s. I assumed that enabling XMP would increase the RAM to the 3200Mhz limit of the motherboard, but whatever the BIOS did has ended up causing the computer to have a fit.

As I only got the new sticks of RAM today, I am well within the Window to send them back if there is no hope of getting them to run at 3200Mhz. This is probably the best option as I bought the second set of RAM specifically so that they could all run at that limit.

StevenGen

https://community.acer.com/en/discussion/comment/1332435#Comment_1332435

As I've told you before, you have mixed ram and that is why the XMP bios switch does not work and is crashing your system, as for XMP ram to work when the bios switch is turned on "you need the same ram types and speed in every DIMM slot @ DDR4-3200MT/s CL22 type ram" the Crucial Pro DDR4-3200MT/s CL22 is a ram that is specifically designed as an XMP ram and can be overclocked and is made for a bios with an XMP switch.

If you have 2x DDR4-2133MT/s Kingston 8GB sticks, fitted from the factory + 2x Corsair Vengeance RGB RS 8GB, C18, 3600Mhz that is why you are getting 2133MT/s ram speed and the XMP SWITCH DOES NOT WORK as you have unequal ram in the DIMM slots and the ram always runs to the lowest common denominating ram speed which is DDR4-2133MT/s ram of the Kingston modules, its a simple formula.

If this answers your question and solved your query please "Click on Yes" or "Click on Like" if you find my answer useful👍

Doomotron

You didn't read my post properly.

The Kingston RAM is not in the system. I've said at least twice now that the new RAM replaced the Kingston RAM.

The RAM sticks in the computer at this very moment are all C18 3600MHz Corsair Vengeance RGB RS 8GB. The only difference between them is that two of them were individually bought and installed at least a year ago, and the ones I installed yesterday are from a 16GB set of two. While the Corsair support page says that you can't mix sets, the specifications for every stick in the computer are identical. I find it hard to believe that mixing identical RAM sticks is the cause of the boot loop when XMP is enabled. Maybe it is, but I can't see why it would be. Maybe I'm just not very intelligent.

The other lead is the speed. The BIOS on the computer has no XMP customisation from what I've seen. There is the possibility that the BIOS simply can't cope with RAM faster than 3600Mhz when XMP is enabled, but I would have assumed that it would slow them down to 3200 or a lower rating that's still faster than the base speed. If that does turn out to be the case, I'll have to send the new ones back because I would have wasted £50 otherwise.

billsey

As stated above, we have had reports where the Corsair memory doesn't work well in XMP mode. Best to return them and purchase a set from a different manufacturer. You don't have to go with Crucial, and if you use their memory selector you will likely want to scroll down instead of buying their most expensive option, which is always at the top for some reason. :) Also, needless to say, don't pick 3200XMP memory, since even with XMP enabled it will only run at the stock 3200 non-XMP speed. I'd look for something like the 3600 or 4000 speed range rather than 4400 or 4800 just to be on the safe side.

Marshall2000

Annoyingly I just purchased a pair of crucial pro CL22 3200 (2 x 16gb) and while they do work and run, and I can even enable XMP, I get the same boot loop and crash issue grrrr.

I'm starting to wish I had just built a pc, as I keep running into issues like this😓

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