21.5" 2019 iMac 6+minute boot after 32 GB ram upgrade

[TopHatPlus]

hey

2019 Imac 21.5" 4K with the latest Ventura update
6 core I7
Fusion drive
4 GB dedicated graphics


I boot windows off a external Ssd through thunderbolt port and play World of warships with a boot time of 1-2 minute and ran the game at 35-40 fps on medium graphics settings and was crashing often

I cut the screen off and upgraded the factory 8 GB RAM to 32 GB of vengeance RAM

The windows side now boots and loads game to play screen in 52 seconds... its incredibly fast and im very happy

The Mac side though.... was booting 40-50 seconds from apple logo to chrome launched and loaded and now runs 5-6 minutes.... once its loads the OS and is done booting it runs FAST 4-5 seconds safari load to a loaded webpage and everything else is FAST

Activity monitor shows 5-6GB ram used with OS and apps running just

I'm a little lost why it boots SO slowly when everything else is SO fast

stock ram was 8 GB (2x4) 2667 mhz
new ram is 32 GB (2x16) 2667 mhz

The googling so far has showed the computer doesn't recognize the ram while booting and once booted is then confirms and uses the ram... my 5th Mac and all were upgraded and never has this issue...

I want to get a new M series chip but I also want windows for gaming...

Any help or trouble shooting tips are appreciated.

 

[Lifeisabeach]

Can you link to the exact modules you purchased? Normally I'd say you have either a defective module or perhaps one or more are not properly seated, but with Windows booting normally, that seems to suggest something else is going on. The first thing I would try is resetting the NVRAM and SMC.

How to reset the NVRAM, PRAM, and SMC on any Mac

If you're experiencing weird glitches with your Mac, doing a reset of your MacBook or desktop Mac could help. Here's how to reset the NVRAM, PRAM, and SMC on either an Intel or M-Series Mac.

www.macworld.com

If that doesn't help, use Onyx or a similar app to clear out the caches. If it still boots slow, if you have an external SSD that connects by Thunderbolt or USB-C, I would clean install macOS to that and try booting off that just to see if there is a difference.

 

[BrianBaughn]

You should run Apple Diagnostics to see if it catches anything…RAM or otherwise.

Use Apple Diagnostics to test your Mac - Apple Support

Apple Diagnostics, formerly known as Apple Hardware Test, can check your Mac for hardware issues.

support.apple.com

I'm not up on any third-party apps for checking RAM. Maybe someone else knows.

It sure wouldn't be easy to just swap the RAM and re-check with the original.

 

[Lifeisabeach]

I'm not up on any third-party apps for checking RAM. Maybe someone else knows.

Ah yes! I've used one before and it nailed a problem for me once. It took me a while to hunt the app down. It's Rember, which is a GUI front-end for memtest. Unfortunately Rember hasn't been updated in ages and is stuck as a 32-bit app, but memtest itself is still around. MemTest86 is an option available that should work. You use it to make a bootable USB stick and run from that. There is a free edition available for download.

MemTest86 - Download now!

Download your free copy of MemTest86 here for USB.

www.memtest86.com

 

[TopHatPlus]

I will try this and update later

thanks for the feedback

this is the ram I used

Corsair Vengeance Performance Memory Kit 32GB DDR4 2666MHz CL18 Unbuffered SODIMM

CORSAIR high performance Vengeance SODIMM memory kit, 2666MHz CL18 1.2V, allows you to automatically boost performance of your without BIOS reconfiguration. Slim and attractive design to ensure physical compatibility with all 6th Generation Intel Core i5 and i7 notebooks. Each module is built usi...

www.amazon.ca

 

[Lifeisabeach]

I will try this and update later

thanks for the feedback

this is the ram I used

Corsair Vengeance Performance Memory Kit 32GB DDR4 2666MHz CL18 Unbuffered SODIMM

CORSAIR high performance Vengeance SODIMM memory kit, 2666MHz CL18 1.2V, allows you to automatically boost performance of your without BIOS reconfiguration. Slim and attractive design to ensure physical compatibility with all 6th Generation Intel Core i5 and i7 notebooks. Each module is built usi...

www.amazon.ca

Here's OWC's listing for RAM that is certified for your iMac:

32GB Memory Upgrade for 21.5-inch iMac 2019

Get everything you need to upgrade your 2019 21.5-inch iMac to 32GB of RAM, and save money by trading in the original memory.

eshop.macsales.com

In comparing specs, I do believe you have the wrong RAM. OWC's modules list timing parameters of 18-18-18-14. The ones you bought indicate latency of 18-19-19-39. This is a pretty significant difference and on point for what a couple articles I had read earlier before posting said could be the problem.

Very slow boot after installing new RAM and other problems

My first problem is that a few days ago after I installed a new stick of 8GB ram, my computer takes a long time to boot. My computer takes around 2 minutes to boot past the "bios" screen then another 2 minutes to boot past the windows loading screen. Before I installed the new ram it took less...

forums.anandtech.com

 

[gilby101]

Fusion drive

That's your slow booting problem. Put macOS on an external Thunderbolt drive.

 

[gilby101]

In comparing specs, I do believe you have the wrong RAM. OWC's modules list timing parameters of 18-18-18-14. The ones you bought indicate latency of 18-19-19-39. This is a pretty significant difference and on point for what a couple articles I had read earlier before posting said could be the problem.

How sure are you of this? The RAM works with Windows, so I would expect it to work with macOS.

 

[Lifeisabeach]

How sure are you of this? The RAM works with Windows, so I would expect it to work with macOS.

I would think so too, but the stone cold reality is that before the RAM upgrade, all was well. Afterwards, not so much. We have a difference in specs with what he purchased vs what a Mac-focused vendor sells for that specific model iMac. And a tech-focused forum discussion where someone with a similar problem on a Windows PC was told the RAM timing could be the issue. I haven't built my own PCs in ages, but that does seem to jibe with what I recall. The problem is staring us in the face. When you hear the sound of hooves, think horses, not zebras.

I would do the troubleshooting steps I suggested earlier just to be sure, including installing macOS clean to an external SSD, just because it's such a nuisance to get back into this model iMac.