Predator P05-640 New ram is slowing down my speed

AlaricB

I have a Predator P05-640 and have been fine with the stock ram of 16gb(2x8gb) until recently. I purchased another 16gb(2x8gb) ram from Crucial. However when I put the ram in and booted my desktop up, the speed was reduced from the stock 4400 to only 2000. I have tried accessing X.M.P. but when I try to save the changes, they do not stick. How can I get the ram back up to the 4400 mhz I was enjoying?

StevenGen

https://community.acer.com/en/discussion/711715/predator-p05-640-new-ram-is-slowing-down-my-speed

We know that the PO5-640 manual and that Acer states the following about the max ram speed that the PO5-640 can have and run:

But you need to update the bios to the last PO5-640 version R01-B0 titled “performance enhancement” that will allow an increases in the ram speed to DDR5-5600MT/s - CL46 type ram, and you can change the XMP bios overclocking settings also to that speed or even higher, other community members have achieved speeds of 5600MT/s with the PO5-640 desktop, so be aware of this and maybe they can contribute to this post.

I don't know what ram you bought from Crucial ram for the PO5-640 and if its their 16GB 2x 8GB DDR5-4800 • CL=40 • NON-ECC • UDIMM • 288-pins • 1.1V • 1Rx16 based • PC5-38400, but if you did then you need to make sure that you exactly match the oem Acer 16GB 2x 8GB DDR5-4XXX ram that Acer fitted into your PO5-640 desktop, use CPUz and look at the Memory and SPD sections for the exact spec of the Acer oem fitted ram, as you need to match those same spec to make the ram run at the exsact and highest speeds of all ram modules, if you have 2x DDR5-4200MT/s and 2x DDR5-4800MT/s with different CLs then the ram speed can be downgraded to the lowest wj=which is either 42000MT/s or even 2000MT/s speed that you are getting.

I suggest that you send the Crucial ram 16GB kit for your PO5-640 back and change the 16GB kit for a new Crucial 32GB Kit (16GBx2) DDR5-5600 UDIMM which is the suitable ram that you should have and its the DDR5-5600 • CL=46 • Non-ECC • UDIMM • 288-pins • 1.1V • 1Rx8 based • PC5-44800 type ram and your ram will run at a speed of 5600MT/s in Windows Task Manager > Performance > Memory. Good luck and hope this helps you out.

For your information I'm including the correct PO5-640 ram modules allocation to DIMMs 1 to 4 chart from the service guide:

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

chris5m

I keep reading on various forums and videos that DDR5 is known to run less stable with 4 sticks. They are saying best performance is achieved with only 2 sticks.

I also have the stock Samsung 16gb(2x8gb) Ram in my P05-640 and planning to remove them completely and upgrade to 32gb(2x16gb). 2 sticks only just to be on the safe side.

Looking at the DIMMs chart above it looks like you have to use all 4 slots if you want to upgrade to 64GB.